The Complete Season One
001. “Pilot”
After an unsuccessful visit to the high-IQ sperm bank, Dr. Leonard Hofstadter and Dr. Sheldon Cooper return home to find Penny, a new neighbor who has moved in across the hall from their apartment. Leonard immediately becomes interested in her, but Sheldon feels he is chasing a dream he will never catch. Leonard invites Penny to his and Sheldon's apartment for Indian food where Penny asks to use their shower, since hers is broken. While wrapped in a towel, she gets to meet their friends Howard Wolowitz, a wannabe ladies man who tries to hit on her, and Rajesh Koothrappali, who suffers from selective mutism in the presence of women and is unable to speak to her.
Leonard is so infatuated with Penny that, after letting her use their shower, he agrees to retrieve her TV from her ex-boyfriend Kurt. However, Kurt's physical superiority overpowers Leonard and Sheldon's combined IQ of 360, and they return empty handed, and without pants. Feeling bad, Penny offers to take the guys out to dinner, beginning a new friendship with them.
002. “The Big Bran Hypothesis”
When Sheldon and Leonard drop off a box of flat pack furniture that came for Penny, Sheldon is deeply disturbed when he sees how messy and disorganized her apartment is. Later that night, while Penny sleeps, Sheldon, extremely obsessive-compulsive and unable to sleep, sneaks into her apartment to clean and organize it; Leonard catches him, but reluctantly helps him clean.
The next morning, Penny realizes that they had been in her apartment and becomes furious. Sheldon tries apologizing to Penny but fails after remarking that Leonard is a "gentle and thorough lover". Later, Penny encounters Raj in the hallway. Although Raj cannot talk to Penny, she calms down talking about the problem to him and hugs him, reasoning with herself that the guys were just trying to help her. Leonard then apologizes, prompting Penny to hug him and forgive him.
003. “The Fuzzy Boots Corollary”
When Leonard sees Penny kissing a man in front of her apartment door, he becomes devastated, thinking she has "rejected" him. The guys convince him to ask someone out at work, so he asks out fellow scientist Leslie Winkle, who preemptively turns him down. As Leonard slips deeper into his depression, thinking about buying a cat, Sheldon points out that he was not actually rejected by Penny, as he had not asked her out. Leonard agrees and promptly asks Penny out to dinner, but she mistakes it as an invitation to hang with all the guys, so Leonard makes up excuses as to why the guys were absent.
On the date, Penny mentions the man Leonard saw was not her boyfriend, but that she has a habit of having weekend-long casual sex encounters to get over relationships. Excited, Leonard regains his confidence, but he accidentally hurts himself and Penny has to take him home. In the end, Leonard does not get the courage to reveal his true feelings to Penny, even though she suspected what he was up to.
004. “The Luminous Fish Effect”
Sheldon is fired from his job as a physicist at the university when he insults his new boss Dr. Eric Gablehauser. His change of circumstance sends him into a downward spiral of depression which results in working on developing luminous fish for nightlights and buying a loom for himself. Worried, Leonard calls Sheldon's mother, Mary Cooper.
When she arrives for a visit, the men realize she is completely the opposite of what they expected: she is sweet, down-to-earth, a devout Christian, and a really good and loving and caring mother. Mary finally forces Sheldon to apologize, and he is given his job back after she flirts with Dr. Gablehauser.
005. “The Hamburger Postulate”
While eating at the Cheesecake Factory where Penny works, the guys run into Leslie. Leslie wants Leonard to play in her string quartet as a new cellist, as the other players are uncomfortable near the current cellist due to the chance he was irradiated at work. After practising in Leonard and Sheldon's apartment, Leslie and Leonard have sex, making Sheldon uneasy.
Penny congratulates Leonard, whom tries to figure out what she meant. Leonard decides to pursue a real relationship with Leslie over an imaginary one with Penny, but when he arrives in the lab, Leslie makes it clear she is not interested in a relationship, and was only using him for a one-night stand to satisfy her sex drive. Leonard later tells Penny, who reassures him and walks away smiling.
006. “The Middle-Earth Paradigm”
The guys are invited to Penny's Halloween party. They originally turn it down as they do not dance but change their minds when costumes are mentioned. At the party, the guys have problems socializing; Sheldon is unable to explain his costume as the Doppler effect since none of Penny's friends are physicists or smart enough to understand it, Raj cannot speak to women, Howard is mistaken for Peter Pan instead of Robin Hood, and Leonard is insecure. Kurt later shows up and confronts Leonard, causing Leonard (and later Penny) to leave.
Penny goes to check on Leonard and apologizes while also very upset about Kurt. Leonard tells her that she is perfect and they kiss, though Penny confesses she is drunk. They return to the party and kiss again in front of Kurt, prompting Leonard to say "That's how we roll at the Shire!", before locking the doors in panic. Meanwhile, Howard cannot find Raj, who ends up going home and having sex with a woman he had met at the party, who found him to be a "good listener".
007. “The Dumpling Paradox”
Penny's promiscuous friend Christy from Nebraska arrives in town, and ends up sleeping with Howard almost instantly, who is dragged to her. The pair take over Penny's apartment, causing Penny to sleep on Leonard and Sheldon's couch for the night. With Howard gone, Penny takes his place playing Halo 3 and ends up being naturally good at it, annoying Sheldon. Furthermore, Howard invites Christy to move in with him (and his mother), taking up all his time.
Distraught over the odd number in the group, Sheldon invites Penny again to play Halo, but she declines to go dancing. Believing that they are falling apart as a group, the guys go to speak to Howard. When they arrive, they hear Christy and Howard's mother arguing loudly, causing Christy to leave. Howard, once again single, goes with the guys to play Halo and the group is restored yet again.
008. “The Grasshopper Experiment”
Raj introduces his parents, Dr. V.M. Koothrappali and Mrs. Koothrappali, via webcam to his friends. However, Raj immediately becomes overwhelmed after his parents try to arrange a date with Lalita Gupta, a childhood friend and dental student, as he cannot talk to women. Howard pretends to be Raj and sets up the date with Lalita by using a fake Indian accent, much to Raj's annoyance. Meanwhile, Penny takes up bar tending for some extra money. As she practices mixing drinks with the guys, they discover that after drinking an alcoholic beverage, Raj can actually talk to women. They decide the date should be at Penny's restaurant, so she and the guys can keep an eye on Raj's behavior while drinking.
On his date, Raj becomes a very obnoxious drunk, and Lalita ends up leaving with Sheldon, who impresses her by complimenting her, comparing her to Princess Panchali, a princess in an Indian fairy tale. Raj tries to explain to his parents what happened, who become angry at him for drinking. Leonard asks Sheldon if he is going to see Lalita again and he replies that he already has a dentist.
009. “The Cooper-Hofstadter Polarization”
Cleaning up after an Internet experiment, Leonard discovers a letter in the trash can, which is an invitation he and Sheldon received to present some research they had done together at an academic conference. Sheldon disapproves of presenting research in person, but Leonard defies him, saying he will go on his own. This causes a rift between the two which Penny tries to mend but accidentally makes worse. At the conference, Sheldon appears and tries to discredit Leonard's presentation by attempting to "blow up" Leonard's head with his mind à la the movie Scanners, causing a physical altercation between the two. Howard records the fight on his cell-phone and puts it on YouTube, but earns the ire of Penny after also taking a picture of her sleeping on his shoulder and posting it to Facebook with the caption "me and my girlfriend".
010. “The Loobenfeld Decay”
Penny is given a part in Rent, but after Leonard and Sheldon hear her sing extremely off-key (with Sheldon commenting, "if cats could sing, they'd hate it too"), Leonard lies to avoid seeing her performance and hurting her feelings. Sheldon becomes worried that Leonard's lie was not good enough, so he creates an intricate lie about his non-existent drug addicted cousin "Leopold Houston", who was in need of an intervention (and thus why they could not see the play).
Sheldon ends up becoming so obsessed with the credibility of his lie that he has Toby Loobenfeld, a research assistant who double majored in Physics and Theatre, impersonate cousin "Leo" to convince Penny that the lie is true. In the end, not only does Leonard still have to see the videotape of Penny's performance, but Penny and "Leo" start flirting as well.
011. “The Pancake Batter Anomaly”
Penny returns from visiting family in Nebraska, but mentions while picking up mail from Leonard that most of her relatives got sick. Sheldon, a germophobe according to Leonard, freaks out and becomes sick, causing his obnoxious personality to increase drastically as he becomes demanding.
Familiar with Sheldon being sick, Leonard and the guys hide from him at a Planet of the Apes series marathon, leaving Penny to take care of Sheldon. However, Leonard breaks his glasses and must re-enter the apartment using help with a web-cam from Howard and Raj. Penny catches him and sticks him with Sheldon. As he tries to escape, he runs into a wall and nearly knocks himself out. In the end, Leonard and Sheldon sit injured and sick on the couch respectively.
012. “The Jerusalem Duality”
Sheldon becomes envious when he meets 15-year-old child prodigy Dennis Kim, who was invited to work at the university, and soon realizes that not only is Kim like Sheldon himself (a child prodigy, obnoxious, and arrogant), but is even smarter than he is. Losing faith in his research, Sheldon annoys his friends by criticizing their work more than usual and contributing to their work. Deciding his work in physics is useless, he aims for the Nobel Peace Prize by attempting to solve the Middle East conflicts: he proposes the creation of an exact replica of Jerusalem in the Mexican desert, which ends up in a giant failure.
The others, tired of Sheldon's behavior, decide to distract Dennis with girls of his age. At his welcome party, their plan works unexpectedly and Dennis leaves with a blonde 15-year-old, using money to get her with him. Sheldon resumes his research while the others are perplexed at how easily Dennis was able to get a girl. The guys spot Dennis drinking heavily and making out in a park and feel sorry for him, but Sheldon mocks Dennis in victory.
013. “The Bat Jar Conjecture”
The guys decide to compete in a physics bowl after finding out that the strong competitors have dropped out, but find Sheldon's showboating too much and kick him off the team. Sheldon, upset, vows to form his own team and compete against them. The guys, in need of a fourth member, ask Leslie; she rejects at first, but agrees after finding out they are going against Sheldon, who has often criticized her research and gender.
The guys name themselves PMS (Perpetual Motion Squad, an unintentional pun on premenstrual syndrome), while Sheldon's team is named AA (Army ants, an unintentional pun on Alcoholics Anonymous) and is composed of himself, the 3rd floor janitor, the lunch lady, and her son (a butcher). PMS win when Sheldon, unable to answer the last question, refuses to accept the janitor's answer, which turns out to be correct. The janitor explains that despite working in America as a janitor, he was a physicist in the former Soviet Union.
014. “The Nerdvana Annihilation”
Leonard buys a time machine online from the 1960 film, The Time Machine, believing it to be a miniature, though it turns out to be the full-sized original. Because the men's efforts to move the cumbersome object into the apartment cause Penny to lose much of her day's time, including a shift at work, she furiously lashes out at them for their childlike preoccupation with various genre memorabilia. Leonard, upset at possibly losing the respect and attention he craves from Penny, decides to get rid of all his collectibles (which Howard refers to as "Nerdvana"), while his friends try to convince him not to, leading to a conflict among the other men over the collectibles of his that they want.
Later, Sheldon turns the tables in Leonard's favor, accusing Penny of being a hypocrite by pointing out her own love of things such as Hello Kitty, Care Bears, Beanie Babies and My Little Pony. Penny, realizing his point, apologizes to Leonard, and encourages him not to give up the things he loves before her new boyfriend Mike shows up. His hope of a relationship with Penny renewed, Leonard decides to keep his belongings. Sheldon ends up having a nightmare where he travels to the future and is attacked by Morlocks. He then "wakes up" sat in the time machine and tells Leonard they need to get rid of it. Leonard agrees that the time machine is too big for the living room and has hired some guys to help move it; the Morlocks, who attack Sheldon again.
015. “The Pork Chop Indeterminacy”
Sheldon introduces the guys to his twin sister, Missy, who all become attracted to her. Raj decides to take part in a drug trial to cure his inability to talk to women, and Leonard insists she stay with them at the apartment. The men predictably begin awkwardly flirting with her, causing Penny to come to her rescue.
Leonard convinces Sheldon to be protective of Missy so that he is more likely to win her heart over Howard and Raj, but Sheldon deems all three unsuitable to be with Missy. Upon learning about Sheldon's plan to find a suitable mate for her, Missy confronts her brother, and Sheldon agrees to let Missy date whoever she wants after she kicks him in the groin. Missy turns Leonard and Howard down. Finally, Raj goes to talk to Missy, and she seems interested in him, but the drug wears off and he is unable to speak to her, forcing Raj to leave defeated.
016. “The Peanut Reaction”
Penny learns that Leonard has never had a birthday party, as his parents did not believe in celebrating anything but achievements. She decides to throw him a surprise party, and blackmails Sheldon to join her by threatening to draw a smiley face on one of his mint condition comic books. However, when the day of the party arrives, Penny finds Sheldon did not buy a present, so she has to drive him to a computer store to pick one up.
Meanwhile, Howard is in charge of keeping Leonard out of his apartment until the party. Howard pretends to eat a peanut bar, to which he is allergic, so Leonard can drive him to the emergency room. However, due to Sheldon's absent-mindedness in the computer store, Howard has to keep Leonard distracted even longer and is eventually forced to actually eat the peanut bar, causing him to swell up in a severe allergic reaction.
017. “The Tangerine Factor”
Penny furiously breaks up with Mike after he posts details about their sex life on his blog, while Sheldon, determined to prove that the Chinese restaurant uses oranges instead of tangerines in their "Tangerine chicken", asks Howard to teach him Mandarin.
As Penny laments her choices in men, Leonard awkwardly asks her out. A few days pass and both become worried that this relationship could ruin their friendship, so both seek Sheldon's advice. Sheldon uses the "Schrödinger's cat" thought experiment to explain that the date has both "good" and "bad" possible outcomes, and the only way to find out is to go on the date and find which outcome it is. When Leonard arrives to pick Penny up, he mentions the experiment and passionately kisses her. She concludes that "the cat is alive" and they leave for dinner.
Leonard and Penny go to the Chinese restaurant, but they leave before entering as they see Sheldon fighting with the owner in Mandarin, and doing it very badly, disturbing the patrons.
The Complete Season Two
018. “The Bad Fish Paradigm”
Continued from the Season 1 finale, Leonard and Penny return from their first date while Howard and Raj spy on them using a webcam. Leonard, spotting the camera, suggests going over to Penny's apartment, but she misunderstands him and tells him to "slow things down". The guys try to convince Leonard that the date did not go too well, which he denies. Penny later tells Sheldon that she lied to Leonard about graduating from community college, feeling Leonard would not want to date a woman who is not smart, and makes him promise not to tell him.
Sheldon finds it difficult to keep the secret and moves out of the apartment as a result. He first stays in Raj's apartment, but after he criticizes Aishwarya Rai (comparing her to Madhuri Dixit), Raj leaves him with Howard. At Howard's house, Sheldon is unable to sleep, so Howard gives him Valium and takes him back to the apartment. Sheldon, in his drugged state, tells Leonard the secret. The next morning, Leonard suggests Penny should join Pasadena City College, but tells her that he does not mind dating someone who is not smart after she asks, to which she slams her door in his face.
019. “The Codpiece Topology”
After the guys return from a Renaissance fair and see Penny with her new boyfriend, Eric, Leonard decides to once again pursue a relationship with Leslie. Leslie agrees to date Leonard, assuming the dominant role before conceding that Leonard should assume the "male role". With this new attitude, Leslie goes as far as evaluating Leonard's genetic defects, and talking about procreating with him. Penny dumps Eric after unsuccessfully using him to make Leonard jealous.
Sheldon explains to Penny that he feels uncomfortable with Leonard dating his arch enemy, Leslie, but approves the relationship after Penny's advice. However, almost immediately, Leslie and Sheldon argue over the validity of loop quantum gravity, which Leslie supports, and string theory, which Sheldon supports. Leslie expects Leonard to back up her beliefs, but when Leonard backs up Sheldon, Leslie dumps him, much to Sheldon's relief.
020. “The Barbarian Sublimation”
Sheldon lets Penny into his apartment after she accidentally locks herself out. Penny, frustrated by not progressing in her acting career and not having sex for six months, becomes curious when seeing Sheldon play Age of Conan. Penny quickly becomes addicted and experiences video game addiction.
After talking with Leslie, Sheldon realizes that Penny needs to have sex to relieve her stress and regain her regular life. Sheldon attempts to set Penny up with an online dating service, but fails. In the end, Penny overcomes her addiction when she realizes she accepted to have a virtual date with Howard. Horrified, she promptly stops playing.
021. “The Griffin Equivalency”
Raj is included in People magazine's "30 Visionaries Under 30 Years Old to Watch" list for his discovery of the trans-Neptunian object 2008 NQ17, sparking jealousy from his friends. Despite Leonard's comments that they need to be supportive, Raj becomes arrogant after receiving star treatment from Dr. Gablehauser and getting an assistant, so the guys ditch him.
Raj invites Penny to People's reception. After the party, a very intoxicated Raj returns home with Penny, and via webcam introduces her to his parents as his girlfriend. The night ends with Penny denying being Raj's girlfriend, and leaving after he becomes sick from over drinking. The following morning, a sober and shy Raj tries to apologize to Penny, attempting to leave a written note, but Penny forces him to utter a barely audible "sorry" before forgiving him.
022. “The Euclid Alternative”
Leonard is working on an experiment for several days, resulting in his inability to drive Sheldon to the university. Sheldon asks Penny, Howard and Raj for assistance, but they all eject him from their vehicles for being annoying. The group finally stage an "intervention" and tell Sheldon to get a driver's license and learn to drive.
After a trip to the DMV, resulting in Sheldon getting his learner's permit, the group set up a driving simulator for him in the living room. Sheldon does horribly as a driver, so he decides to live in his office at the university so that he does not have to commute. However, Leonard reveals that he actually finished his experiment a week ago and just wanted to avoid driving Sheldon to work.
023. “The Cooper-Nowitzki Theorem”
After a lecture by Leonard and Sheldon, a graduate student named Ramona Nowitzki becomes obsessed with Sheldon and insinuates herself into his life as a platonic girlfriend/assistant. Ramona proves to be a helpful influence on Sheldon's work, but she annoys him by prohibiting his recreational activities and forcing him to solely concentrate on his research. Eventually Sheldon realizes that he is in "some sort of relationship" with Ramona, and seeks help from Penny and Leonard to get rid of her, without success.
Sheldon eventually reaches a breakthrough in his research and, grateful to Ramona, asks if he can do something for her. Ramona suggests they share credit for his discovery calling it "The Cooper-Nowitzki Theorem", but Sheldon refuses and kicks Ramona out. After reading a draft paper of the new theorem, another student approaches Sheldon in the same way Ramona did the first time.
024. “The Panty Pinata Polarization”
When Penny's cable gets cut, she comes over to the guys' apartment to watch America's Next Top Model. However, she accidentally sits on Sheldon's spot on the couch and touches his onion rings, prompting Sheldon to banish her from his apartment. Sheldon and Penny then aim to one-up the other, with Sheldon cutting Penny's Wi-fi and Penny ruining Sheldon's laundry night. Eventually, after Sheldon places Penny's laundry on a telephone wire, Leonard tells Penny to complain to Sheldon's mother. Sheldon's mother forces Sheldon to apologize to Penny and give back her laundry.
Meanwhile, Howard finds out that the models in America's Next Top Model are in a house in Los Angeles. Determined to get in the house, he and Raj search the house using all available technology and successfully find it. Howard and Raj end up entering the house by posing as cable guys.
025. “The Lizard-Spock Expansion”
Howard meets Dr. Stephanie Barnett at a bar and invites her to drive the Mars rover at the Jet Propulsion Laboratory, but the plan fails when the rover gets stuck in a Martian ditch. Howard subsequently destroys all security tapes and hard drives relating to the mission. Afterwards, Leonard admits to Howard that he has started dating Stephanie, but Howard forgives him when Stephanie sets up him with another friend, and invites him on a double-date. In the end, Howard hears the news on TV that the rover found water on Mars in the bottom of the ditch, but as the data was destroyed, no one was able to determine who was responsible for the discovery.
Meanwhile, Sheldon and Raj play a game of rock-paper-scissors-lizard-Spock, a "The Lizard-Spock Expansion" of the traditional game rock-paper-scissors. They play to decide who gets to watch what on TV, but they both choose Spock. They, along with Howard, play the game for the last dumpling. When they choose all Spock again, they play it where none of them may hold up Spock, but they all choose Spock again anyway.
026. “The White Asparagus Triangulation”
Sheldon considers Stephanie the only "tolerable" girlfriend that Leonard has had, and tries helping Leonard in the relationship as a result, fearing Leonard will ruin it. However, Sheldon irritates Leonard by joining the couple when they have a romantic dinner and go to the movies. After believing that Leonard is losing Stephanie, Sheldon attempts to prove Leonard's physical superiority to Stephanie by having him open a jar of white asparagus. However, Leonard shatters the jar by accident and has to get stitches.
Following the trip to the hospital, Leonard finds Sheldon hacked his Facebook account and changed his status to "In a relationship". Leonard worries that this will make him look desperate, but then finds that Stephanie changed her status to "Stephanie Barnett is in a relationship with Leonard Hofstadter". Sheldon then proclaims "Dr. Sheldon Cooper for the win."
027. “The Vartabedian Conundrum”
Stephanie moves into Leonard and Sheldon's apartment for practical purposes, though Leonard does not acknowledge this. Stephanie gives a physical examination to Sheldon, who complains about a ringing in his ear, but after Penny, unaware of the relationship, shows up in the guys' apartment, she attempts to prove to Leonard that Stephanie is living with him. After Stephanie buys Leonard new clothes that he ends up hating, Leonard realizes that his relationship with Stephanie is moving too fast for him.
Leonard tries to tell Stephanie to move out, but every time he tries, she diverts him by initiating sex. Meanwhile, Sheldon sneaks into the hospital to test himself, as the ringing has not stopped. By the time Leonard gets back to the apartment, Stephanie has diagnosed Sheldon with a fake larynx inflammation, and instructs him not to speak at all. She calls the diagnosis a "Sheldonectomy".
028. “The Bath Item Gift Hypothesis”
Sheldon worries about the approaching Christmas holidays and his indecision about what to buy for Penny. After deciding on a basket of bath items, he discovers a wide selection available, but unsure about what Penny is going to get him, he buys an entire array to cover all contingencies. Penny's gift to Sheldon is a napkin both autographed and used by Leonard Nimoy. Sheldon, overwhelmed since he now possesses Nimoy's DNA and can grow his own Leonard Nimoy, gives Penny all of the gift baskets and then a rare "Sheldon" hug.
Meanwhile, Leonard meets visiting researcher and fellow experimental physicist Dr. David Underhill. Although Leonard envies David for being handsome and a more successful physicist than himself, he still jumps at David's offer to help him in his research. However, things come to a halt when David meets Penny and the two start dating. They later break up after Penny finds out he is married.
029. “The Killer Robot Instability”
Howard designs a robot, M.O.N.T.E. (Mobile Omnidirectional Neutralization and Termination Eradicator) for the "Southern California Robot Fighting League Round Robin Invitational", which the guys plan to enter. When Penny arrives at the apartment, Howard begins to flirt with her, but pushes her too far and causes her to furiously lash out at him. Depressed, Howard returns home and remains in his room, refusing to go to work. Leonard advises Penny to go to Howard's house and apologize. Howard tells Penny about all his failed romances, and Penny consoles him by saying that he is a good guy at heart and he just tries too hard to get girls. After this however, Howard tries to kiss Penny, which results in her punching him. Howard is left happy, feeling he is halfway to 'pity sex'.
Meanwhile, the guys' co-worker Barry Kripke also enters the competition and challenges Sheldon and the guys to a one-on-one fight using their robots. Sheldon accepts, but Kripke's robot turns out to be far superior to M.O.N.T.E. and, with Howard indisposed, Barry easily wins. Sheldon refuses to throw the towel in, resulting in M.O.N.T.E. being destroyed by Kripke's robot.
030. “The Friendship Algorithm”
Sheldon hears that Kripke is in control of an Open Science Grid computer, so he plans to befriend him to gain access to it. Socially inept, Sheldon struggles, and his current friends prove not of much help in the same respect. During a trip to the bookstore, Sheldon tries making friends with a little girl, but Leonard gets him to quickly exit before he is picked up as a pedophile.
Sheldon uses a children's book to help him design a flowchart to get new friends. This pays off as Sheldon goes rock-climbing with Kripke, but Sheldon faints due to his fear of heights. Back at the apartment, Sheldon decides to cut off Raj as a friend to make room for Kripke. However, when Kripke reveals he does not actually control the computer, Sheldon dismisses him and restores Raj as a friend.
031. “The Financial Permeability”
Penny is experiencing financial difficulties, which may result in her finding a new place to live. Sheldon, after discussing it with her, does the logical thing and lends her some money. After Leonard learns about Penny's problems, he tries to help her cut expenses, and in the process learns that her ex-boyfriend Kurt owes her $1,800.
Without telling Penny, Leonard and the guys go to Kurt's place to collect the money. Though they are unsuccessful, Kurt writes "I owe Penny $1800, Kurt" on Leonard's forehead in indelible ink. Penny later pays Sheldon back after Kurt pays her back, but, much to Leonard's disappointment, Kurt never told Penny about Leonard's visit, and instead took the opportunity to get back together with her.
032. “The Maternal Capacitance”
Leonard becomes worried when he learns his mother, accomplished psychiatrist and neuroscientist Dr. Beverly Hofstadter, is coming to visit. Upon arriving, Beverly meets Penny, and by the time they reach Leonard's apartment, Penny is in tears after having her childhood issues psychoanalyzed. Sheldon, on the other hand, instantly develops a comfortable relationship with Leonard's mother, who turns out to be as strict and logical as himself. Howard and Raj also meet Beverly, but after learning that Howard still lives with his mother and Raj cannot talk to women, she is quick to declare that they are in an "ersatz homosexual marriage".
Leonard later goes to talk to Penny and they comfort each other by discussing their respective childhood issues with their parents. As they become drunk, Penny and Leonard are about to have sex, but Leonard ruins the moment by using psychology and noting that he is having sex with his mom and she with her dad. Disgusted, Penny throws Leonard out of her apartment.
033. “The Cushion Saturation”
After a paintball match, Penny accidentally shoots a paintball gun at Sheldon's couch cushion, and she and Leonard have a hard time getting it cleaned. Sheldon, upset and still dissatisfied with dry-cleaning, team-kills Penny in the next paintball game, causing the others to surrender.
Meanwhile, Leslie and Howard begin a relationship after sleeping together during the match. Leslie secure funds for his work and even invites him to a trip to the CERN Large Hadron Collider project in Geneva. However, this turns out to be just Leslie's way to control Howard. Although initially reluctant, Howard later happily accepts his role as a "sex toy/arm candy".
034. “The Terminator Decoupling”
The guys take a trip to a conference in San Francisco to meet guest speaker and 2006 Nobel Prize laureate Dr. George Smoot. On the train, the guys realize Summer Glau of Terminator: The Sarah Connor Chronicles is on board. Raj is the first to approach Summer, and she gets along with him, but Raj notices that he drank non-alcoholic beer before approaching her, causing a placebo effect and Raj to revert to his usual timid self. Howard then takes over, but creeps Summer out with his awkward style. Leonard finally gets his chance, but Summer gets off the train before he can introduce himself.
Meanwhile, Sheldon realizes he forgot his USB flash drive with a paper he wants to show to Smoot, and needs Penny's help to find it and email it to him. However, Smoot is not impressed, asking him "With all due respect, Dr. Cooper, are you on crack?"
035. “The Work Song Nanocluster”
Penny develops home-made hair barrettes called 'Penny Blossoms' and aims to turn them into a profitable homebased business. With Sheldon's help, Penny develops an efficient assembly line before Leonard, Howard, and Raj join in. Leonard designs the sales website, and they immediately get an order for a thousand Penny Blossoms from the East Rutherford, New Jersey Gay-Lesbian-Bisexual-Transgender Alliance.
Despite their initial happiness, they realize Leonard included a one-day rush shipping option on the website, so the group has to work all night to fulfill the order. However, the next morning, they discover that the same group doubled their order, leading the guys to quit in exhaustion. Sheldon, drinking coffee to stay awake, races around the apartment dressed as The Flash.
036. “The Dead Hooker Juxtaposition”
The former tenants of the apartment above Leonard and Sheldon's move out. After an unsuccessful attempt by Howard to rent the apartment, an attractive blonde woman named Alicia moves in. Alicia, like Penny, is an aspiring actress who obtains a role as a dead hooker in an episode of the TV series CSI. The guys become fascinated with Alicia, and she takes advantage by having them labor for her. As a result, Penny loses the guys' attention, and also comes to resent the way Alicia exploits them.
Penny tries to win her friends back by bribing them with Chinese food, offering to watch Battlestar Galactica, and even memorizing a quantum physics joke. After Alicia brags about her exploitation of the men, while also expressing derision of their incomes, Penny confronts her. Alicia responds by saying that Penny exploits the men in the same way that she herself does, causing Penny to attack her. After the fight, the guys learn that Alicia is sleeping with one of the CSI producers, leading Penny to comment that Alicia is a "dead whore on TV, live one in real life".
037. “The Hofstadter Isotope”
When Penny accompanies the guys to the comic book store to buy a present for her nephew's birthday, the owner, Stuart, asks her out on a date, prompting jealousy from Leonard. To take his mind off the situation, Leonard asks Howard and Raj to take him to a bar to socialize with women, but neither he nor Howard succeed in finding a woman. Stuart's date with Penny goes well, but they are interrupted by Sheldon, who starts an argument with Stuart about who Bruce Wayne's successor as Batman should be, during which Penny falls asleep.
038. “The Vegas Renormalization”
Leslie ends her "friends with benefits" relationship with Howard, upsetting him. Leonard and Raj decide to take him on a trip to Las Vegas, Nevada to cheer him up. There, a prostitute named Mikayla approaches Raj, and he and Leonard decide to hire her for Howard. Howard soon realizes she is a prostitute, but nevertheless thanks Leonard and Raj for setting up the "date".
Meanwhile, Sheldon, who has declined to go to Las Vegas, is delighted to spend the weekend alone, until he forgets his apartment key. He is forced to spend the night at Penny's apartment, and, in the process, thinks he has a better understanding of the term "friends with benefits".
039. “The Classified Materials Turbulence”
Howard celebrates the launch of his latest invention, a zero-gravity human-waste disposal system (a space toilet) to be used in the International Space Station, by buying all of his friends new comic books. However, Howard discovers he made a mistake that will cause the toilet to fail and explode after 10 flushes, so the guys convene to try and fix it (a la Apollo 13 's Ken Mattingly), working for a whole night to find a solution and even testing the toilet with meatloaf which Howard brought from his mother. In the end, the ISS astronauts report to NASA that they are going on an unscheduled "spacewalk", suggesting that Howard failed.
While at the comic book store, Stuart tells Leonard that he is having a second date with Penny and asks for advice. Leonard deliberately avoids Stuart's request and gives him bad advice. The next day, Leonard feels guilty and goes to apologize to Stuart. Stuart reveals the date went okay until he and Penny started making out in his car and Penny accidentally called him "Leonard."
040. “The Monopolar Expedition”
Sheldon wins a National Science Foundation grant to go on a three-month expedition to the Magnetic North Pole to detect magnetic monopoles and prove the validity of string theory. After some hesitation, he decides to go and wants Leonard, Howard and Raj to come with him; they too initially hesitate as it would mean being locked in a cabin with Sheldon for three months, but finally agree. To prepare, Sheldon and the guys use the freezer at the Cheesecake Factory, however this later proves unnecessary as they discover they are going to spend their time in a warm cabin.
On the night before the expedition, Leonard expresses doubts on going as it would mean he would not see Penny for the whole summer. He also thinks that Penny is going to miss him after she gives him a blanket with sleeves and a long hug. The next morning, when Leonard meets Penny again, she claims to simply have wished him a safe trip, but after he closes the door, she sadly whispers "It means I wish you weren't going". The guys arrive in the Arctic and agree to abide to the same rules as in the apartment.
The Complete Season Three
041. “The Electric Can Opener Fluctuation”
The men return home from their three-month expedition at the Magnetic North Pole (from the Season 2 finale), and Penny finally reveals her feelings for Leonard by kissing him as soon as he visits her. Meanwhile, Howard and Raj reveal to Sheldon that they and Leonard tampered with his experiment on magnetic monopoles by using an electric can opener. Sheldon is angry as he had already submitted his results to the university, and is forced to make an apology, making him the butt of jokes from everyone at the university, particularly Kripke. Feeling betrayed, Sheldon returns to his home in Galveston, Texas. On Penny's advice, Leonard, Howard and Raj reluctantly go to Galveston to bring him back.At his home, Sheldon becomes increasingly annoyed with his mother's strict Christian lifestyle. When the guys come over and plead with Sheldon to come back to Pasadena, he initially refuses, but following an argument with his mother about evolution, he forgives them and returns to Pasadena. Penny and Leonard then finally have sex, but both of them now feel their relationship got weird.
042. “The Jiminy Conjecture”
Leonard and Penny struggle to recover from a not-so-great first hookup and try to figure how to overcome it. A romantic evening between the pair soon turns into a night filled with drunken sickness. The next day Penny talks to Sheldon and Sheldon points out that if things do not work out, they can always return to being friends. After Sheldon tells Leonard that he spoke to Penny, Leonard goes to Penny's apartment. Penny tells Leonard that being friends was much simpler and that it will take the pressure off, something that Leonard agrees to. They decide to go back to being friends, however they quickly give in and resume their relationship.
Meanwhile, Sheldon and Howard stake their most valuable comic books (Sheldon's "Flash of Two Worlds" against Howard's Fantastic Four #48) on a bet to determine the species of a cricket after they hear it chirping. Sheldon claims it is a snowy tree cricket, but Howard insists it is a common field cricket. Along with Raj, the three spend a long time locating the cricket. They settle the bet by taking "Toby" to Professor Crawley, Caltech's depressed entomologist, who has just lost funding for his lab. Howard is proven correct that it is a common field cricket, so Sheldon has to give up his copy of The Flash.
043. “The Gothowitz Deviation”
After a sexual encounter that results in Penny's bed breaking, Penny and Leonard sleep in Leonard's room, much to Sheldon's dismay. Sheldon tries to condition Penny using chocolate, despite Leonard's opposition, rewarding her for what he considers to be correct behavior.
Meanwhile, Howard and Raj go out to a goth club and meet two girls. After they say they would prefer to go "somewhere else and have some fun," the four end up in a tattoo shop, which makes Raj and Howard reveal their true selves and admit to not being goths, missing their opportunity with the girls rather than getting tattoos.
Note: Leonard, Sheldon, and Penny are watching the anime Oshikuru: Demon Samurai, which is a reference to a 2004 episode of Two and a Half Men ("The Salmon Under My Sweater") in which Charlie and Jake collaborate on the theme song to the same show. Both shows were co-created by Chuck Lorre.
044. “The Pirate Solution”
Raj's research on trans-Neptunian objects comes to a dead end and he faces deportation to India unless he gets a new job. After he unsuccessfully applies for other jobs at the university, Sheldon offers Raj a chance to work "for" him, rather than "with" him. Raj reluctantly accepts Sheldon's offer. Later, Sheldon and Raj disagree on how to solve a work-related problem and Raj walks out. Sheldon apologizes to Raj after realising he was right (but does not concede to him being wrong), and they agree to continue working together.
With Raj working for Sheldon, Howard feels lonely, so he tries to hang out with Leonard and Penny (even making them breakfast). They tell him that they need to be alone together, but feel guilty and bring him back.
045. “The Creepy Candy Coating Corollary”
Leonard reluctantly agrees to fulfill a pledge he made to Howard years earlier and asks Penny to set Howard up with one of her friends. Penny introduces Howard to her friend Bernadette and they go on a double-date. It firstly seems like they have nothing in common, but they start to bond when they learn about each others' problems with their mothers.
Meanwhile, Sheldon enters a collectible card game tournament after he hears that Wil Wheaton, for whom he harbors a deep resentment for missing a 1995 Sci-Fi convention, is also participating. With Raj as his partner, they reach the final match against Wil and Stuart. Just as Sheldon closes in on victory, Wil lies, claiming his grandmother's death prevented him from appearing at the convention, which touches Sheldon's heart. Sheldon allows Wil to win, but Wil then admits to lying, leaving Sheldon even more resentful.
046. “The Cornhusker Vortex”
Penny invites her friends over to her apartment to watch the Nebraska Cornhuskers football game that Saturday, but does not invite Leonard as he is not a football fan. Determined to fit in with his girlfriend's friends, Leonard learns the rules of football from Sheldon, who is highly knowledgeable about football having grown up in football-crazy Texas. Using the knowledge, Leonard goes over on Saturday to watch the game, but his comments are too clinical and he fails to fit in with Penny's friends. He later becomes bored and leaves at half-time to fly kites with Sheldon.
Meanwhile, Howard upsets Raj after abandoning him during a kite fight with Leonard and Sheldon to pursue a girl and causing them to lose. Howard decides to make it up to Raj by spending an entire Saturday with him at the La Brea Tar Pits, but fails to keep his promise and again abandons Raj at the tar pits to pursue another girl.
047. “The Guitarist Amplification”
When Penny invites her guitarist ex-boyfriend Justin over to sleep on her couch, Leonard becomes upset. They start a fierce argument, which makes Sheldon, reminded of memories of his parents fighting, upset. He tries to convince Penny to make up with Leonard, but ends up telling her how Leonard dislikes her temper, which only makes her angrier. Upset with the constant bickering between the two, Sheldon leaves his and Leonard's apartment.
Sheldon tries to take refuge in Raj's apartment, but sees him arguing with his parents over webcam. He then goes to Howard's house, but hears him arguing with his mother. Leonard and Penny begin to search for Sheldon and eventually find him at the comic book store. They manage to convince Sheldon to come back to the apartment, but not before allowing him to buy a robot and a comic book. Justin ends up sleeping on the couch in Leonard and Sheldon's apartment (with Sheldon sitting in his spot) and Leonard and Penny, having finally made up, sleep together in Penny's apartment.
048. “The Adhesive Duck Deficiency”
Sheldon hears Penny crying for help after slipping in her shower and dislocating her shoulder. Sheldon is forced to help her dress and drive her to the hospital emergency room, despite not having driven a car before. Sheldon drives slowly and annoys Penny at the hospital, but Penny successfully receives aid. Also under the influence of strong analgesics, Penny forces Sheldon to sing Soft Kitty to her while helping her into bed.
Meanwhile, Leonard, Raj and Howard go on a camping trip to watch the Leonid meteor shower, but all succumb to the effects of "magic" cookies given to them by Deadhead campers nearby. Raj, Howard and even Leonard make fun of Leonard's American accent while looking at the stars. They then share a conversation about their secrets; Raj talks about what it would be like to be king of the rabbits, Leonard thinks of changing his name to "Angelo", and Howard admits that he lost his virginity to his second cousin. The trio begin to run out of food, but Howard remembers that his mother packed food for him and shares it with Leonard and Raj. The trio then succumb to the effects of munchies and forget about the meteor shower, with Leonard and Raj making fun of Howard's experience with his second cousin.
049. “The Vengeance Formulation”
After their third date, Bernadette asks Howard where their relationship is going. Howard avoids her for a week, thinking about whether he should "settle" for her or hold out for the dream of superstars like Megan Fox. After a dream in his tub involving a romantic-evening-turned-lecture from Katee Sackhoff, he decides that he should stick with reality. Howard proposes to Bernadette at The Cheesecake Factory, but gets rejected. In order to win back her affections, he then sings her his version of the song "Bernadette" (by the Four Tops), and succeeds when she declares it the most romantic thing anyone has ever done for her.
Meanwhile, Kripke severely embarrasses Sheldon on National Public Radio's talk show Science Friday by filling Sheldon's office with helium so that his voice is higher-pitched than usual. While at first pouting and accepting defeat, Sheldon is convinced by Leonard and Raj (who originally enjoyed the prank) to fight back. Sheldon takes revenge on Kripke by setting off gooey foam into Kripke's office, but the trick backfires when the visiting Caltech president and board of directors are also hit. Sheldon gives himself away with a pre-recorded video stating that he has sent the taped trick to YouTube, and proclaims himself the mastermind, also giving Leonard and Raj away.
050. “The Gorilla Experiment”
Bernadette joins the guys and Penny for dinner and shows an interest in physics, particularly in Leonard's work. Leonard offers her the chance to tour his lab and watch him conduct an experiment. Howard becomes jealous and accuses Leonard of trying to steal Bernadette's heart from him. After Leonard texts Bernadette that Howard has become jealous, Bernadette storms out before having sex with Howard, accusing him of trying to control whom she takes an interest in. Howard apologises to Bernadette the following day as she arrives to watch Leonard's experiment, and they kiss and make up.
Meanwhile, Penny, jealous over the fact she cannot talk to Leonard about his job, asks Sheldon to teach her physics. After teaching her, Penny ends up spouting off a prepared spiel Sheldon taught her while the group has dinner.
051. “The Maternal Congruence”
At Christmas, Leonard's mother visits, much to Leonard's horror and Sheldon's delight. Penny becomes upset after Leonard failed to tell her about his mother's visit, (nor his mother about their relationship), and the problem gets worse when Leonard learns that Sheldon has been in touch with his mother. Leonard is told about his parents' pending divorce, his mother's surgery, and the death of his dog, all of which Sheldon had known for weeks.
Beverly questions Howard and Raj about what she views as their ersatz homosexual relationship (alluding to her last visit in The Maternal Capacitance), goes out drinking with Penny, and shares a passionate kiss with Sheldon when she returns to the apartment (which they later agree to keep secret from Leonard), though she remarks that she would prefer the busboy she met at The Cheesecake Factory.
052. “The Psychic Vortex”
Leonard and Penny go on a double-date with Howard and Bernadette, but when Penny reveals that she has taken career advice from a psychic, Leonard laughs, infuriating her. Howard tells Leonard that he will have to accept that people have differing beliefs if he wants to maintain a relationship, so Leonard apologizes to Penny and agrees to visit her psychic, despite her having declined to read a book debunking psychics.
Meanwhile, Sheldon and Raj attend a university mixer, with Sheldon as Raj's wingman after Raj bribes him with a Limited Edition Green Lantern lantern. They meet Abby, who takes a liking to Raj, and her friend Martha, who tries to connect with Sheldon. The four play Rock Band at Sheldon's place for a first date. For a second date, Raj bribes Sheldon with his pair of Hulk hands, signed by Stan Lee. After Sheldon announces that he is going to bed, Martha asks if she can stay in his room to avoid Raj and Abby, who are "getting busy". Sheldon obliges, but immediately leaves to sleep in Leonard's room, leaving Martha alone.
053. “The Bozeman Reaction”
Leonard and Sheldon return from dinner to find their apartment broken into and their TV, laptop, hard drives, video game consoles and video games stolen. Sheldon fears being alone in the apartment after the robbery, so he forces Leonard and Penny to stay with him. The next day, Howard designs a state-of-the-art security system for the apartment using components he "borrowed" from the Department of Defense.
After Sheldon gets caught in the security system, he decides that the apartment is no longer safe and plans to leave Pasadena for a safer city. After rejecting Enid, Oklahoma, Boone, North Carolina and the entire state of Nebraska (because Penny is from there), he decides to move to Bozeman, Montana. But when Sheldon arrives there, he gets robbed again, so he returns to Pasadena.
054. “The Einstein Approximation”
Sheldon's search for the answer to a physics problem keeps him up for several days and he becomes obsessed with finding the answer. His obsession leads him to visualize food as atoms and even sneak out in the middle of the night to go to the mall ball pit. He then decides that he needs a menial job to think better since Albert Einstein came up with the Theory of Relativity while working at a menial job at the Swiss patent office. Since the United States Patent and Trademark Office is in Washington DC, and he does not want to move out of Pasadena, Sheldon interviews for any menial job with the County of Los Angeles. At the county office, Sheldon angers the woman interviewing him and security remove him. Sheldon then decides to work at the Cheesecake Factory with Penny as he considers her job the most menial of all. He works as a busboy and waiter without actually being hired or demanding pay, and turns out to be a more efficient waiter than Penny until he drops and breaks a tray of dishes. The scattering of the shattered pieces leads him to the answer to his problem, and he promptly walks out without cleaning up the mess.
Meanwhile, Leonard, Penny, Howard and Bernadette go to disco night at the roller skating rink. Raj is left out as he does not have a girlfriend, but later successfully pressures Howard to take him to the skating rink as it was his idea.
055. “The Large Hadron Collision”
Leonard announces to the guys that a professor is unable to attend a conference in Switzerland and visit CERN's Large Hadron Collider, so he has been designated to be his replacement, and gets to take one guest with him. Sheldon wants to go, but Leonard decides to take Penny as the trip would coincide with Valentine's Day, their first together as a couple. Sheldon is distraught and begins to constantly give signs indicating that Leonard "betrayed" him. He gives Leonard breakfast in bed to change his mind, but Leonard is firm on taking Penny.
Sheldon later convinces Penny to drop out of the trip, but this does not go down well with Leonard, who terminates their friendship. Later that night, Penny falls ill, so Leonard asks Sheldon to accompany him to Switzerland in Penny's place, but Sheldon also falls ill, having hugged Penny and been given the bug. As a result, Raj accompanies Leonard to Switzerland while Sheldon and Penny spend Valentine's Day together.
056. “The Excelsior Acquisition”
Stuart announces that Stan Lee is coming to the comic book store on Thursday to sign comic books, much to the guys' excitement. However, Sheldon cannot attend as he has to appear in court after running a red light while driving Penny to the hospital in the episode "The Adhesive Duck Deficiency". At court, Sheldon insults the judge and is imprisoned as a result. Sheldon later apologizes to the judge and is freed, but falls out with Penny since she made him miss meeting Stan Lee. To make it up to him, Penny takes Sheldon to Stan Lee's house to meet him, but Stan, not impressed by their intrusion, sarcastically invites them in. Sheldon, not understanding sarcasm, enters Stan's house, causing him to call the police. In the end, Sheldon gleefully returns to his apartment with a restraining order from Stan and hangs it next to his restraining order from Leonard Nimoy.
057. “The Precious Fragmentation”
The guys return to the apartment with a large box of TV and movie collectibles from a garage sale, including a prop version of the One Ring. This turns out to be a prop made for The Lord of the Rings film trilogy, with high value to collectors, and the four promptly argue over who gets to keep it. Leonard eventually gives it to Penny for safekeeping. Sheldon sneaks into Leonard's room (where Penny is sleeping) and tries to steal the ring, but she wakes up and punches Sheldon.
The next day in the cafeteria, the guys all grab onto the ring and decide whoever is the last one holding the ring will get to keep it. Leonard removes himself from contention when Penny shows him the contents of a bag she got from Victoria's Secret. Sheldon, Raj and Howard then all fall asleep and let go of the ring. The next morning, Leonard says he sent it back to the original owner, but actually kept it hidden in his room. That night, Sheldon tries to take the ring again and he and Leonard wrestle for it on Leonard's bed. Penny walks out of the room and mutters to herself about how she should "go back to dating dumb guys from the gym."
058. “The Pants Alternative”
Sheldon is delighted when he wins a science award, but is terrified of accepting it because of his fear of speaking to a public audience. Leonard, Raj and Penny offer to help Sheldon overcome his fear, with Sheldon christening himself, Leonard, Raj and Penny as the C-Men (Cooper-Men), but all the C-Men fail to overcome Sheldon's fear; Raj tries to teach Sheldon meditation to calm his nerves, but Sheldon instead imagines a Godzilla-like monster approaching his simulated city Sheldonopolis; Penny takes Sheldon to buy a new suit to give him confidence, but Sheldon is more interested in weird and fancy suits; Leonard attempts a psychotherapy session with Sheldon, but Leonard actually ends up having a nervous breakdown after reminiscing a humiliating incident with his mother.
As a last-ditch solution, Penny offers Sheldon alcohol. This solution actually works, but it makes Sheldon drunk and he speaks nonsense during the awards ceremony. At one point in his speech, Sheldon drunkenly removes his pants. When Sheldon wakes up the next morning, unaware of the events which happened the previous night, he sees his humiliating speech uploaded on YouTube.
059. “The Wheaton Recurrence”
After having sex, Leonard says "I love you" to Penny, but she only replies "Thank you", prompting both of them to start thinking about where their relationship is heading. The next night, Penny and the guys have a bowling match with Stuart and some of the comic book store regulars (with the loser to be publicly humiliated in a fashion to be chosen by the victor). As one member of Stuart's team could not make it, Stuart substitutes him with Wil Wheaton, with Sheldon vowing revenge for what Wheaton did to him in The Creepy Candy Coating Corollary. During the match, Leonard offers Penny chili cheese fries, to which she expresses her love of chili cheese fries. Angry that Penny could describe her feelings for food but not for him, Leonard starts a fierce argument with her, following which she leaves the bowling alley in a huff. Without Penny, the guys are forced to forfeit the match.
The next day, Sheldon makes Leonard and Penny supposedly patch things up and then schedules a rematch that night. During the match, Wheaton tells Penny that he endured two years of misery with a girlfriend who could not say "I love you" to him. When Penny goes to bowl, she feels pressured by Leonard's encouragement and lashes out at him. Realizing that she cannot say "I love you" to Leonard, she breaks up with him and storms out of the bowling alley again. The guys again have to forfeit the match, and Wheaton reveals to Sheldon that he intentionally broke up the couple so that his team would win. In the end, the guys have to enter the comic book store dressed up as female superheroes under Stuart's idea of humiliating them for losing the match.
060. “The Spaghetti Catalyst”
Leonard and Penny have broken up and are no longer talking to each other. Sheldon continues to maintain contact with Penny and goes over for a spaghetti dinner at her apartment. Howard tells Sheldon that he cannot be friends with both Penny and Leonard, but Sheldon has dinner with both the guys and Penny. Unable to keep his friendship with her secret, he reveals to Leonard that he is still friends with Penny, which Leonard does not mind. The next day, Penny bumps into Leonard in the laundry room and tells him that she is taking Sheldon with her to Disneyland that Saturday. When she drops Sheldon home late on Saturday night and puts him to bed, she tells Leonard that they can remain friends despite their break up, which he accepts. However, he suggests that they have a friends with benefits relationship, which she refuses.
061. “The Plimpton Stimulation”
Dr. Elizabeth Plimpton, a cosmological physicist from Princeton University, accepts Sheldon's invitation to stay over at the apartment during her visit to Caltech. However, she instead takes an immediate interest in Leonard, and the two end up sleeping together. The next morning, Penny learns about their tryst and becomes jealous. Leonard assumes that he and Elizabeth are now an item and shows her around, introducing her to Raj and Howard.
Later that night, Howard and Leonard go to Raj's apartment for Halo night and find Elizabeth (trying to seduce Raj). When she sees Howard and Leonard as well, she suggests role-playing sex with all three of them, much to the shock of the men. Raj manages to lock the other two out of the apartment so he could be alone with Elizabeth. Back home, Leonard and Penny discuss whether or not he needs to explain to Penny what happened. Although Penny keeps insisting that he does not, Leonard explains that he had sex with Elizabeth because "she let [him]".
062. “The Staircase Implementation”
Leonard fights with Sheldon over the setting of the thermostat before storming out of the apartment and visiting Penny, who had been listening to the argument. He then proceeds to tell Penny about how he met Sheldon back in 2003.
Sheldon's departing former roommate and Louie/Louise (the transvestite male then occupying the apartment that Penny moves into in the first episode) meets Leonard and both warn him that Sheldon is "crazy". Having found the apartment, Leonard meets Sheldon whom, at the door, questions Leonard about the sixth noble gas (Radon) and "Kirk or Picard?" before allowing him to enter. Leonard goes to sit down, but learns about the acquisition of the lawn chair, which Sheldon calls "my spot". Leonard then undergoes further examination, and the ensuing rigorous interview questions and intrusive conditions suggest Sheldon's literalness, rigidity, egotism, and peculiar priorities.
Another flashback, introduced by Penny wondering why Leonard continues to live with Sheldon, reveals two events: Sheldon inadvertently kept Leonard from revealing a top secret rocket fuel to his girlfriend at-the-time Joyce Kim, a North Korean spy, angering her so much that she storms out. Later, Sheldon comes in to see Leonard brought in a new couch and playing video games, which eventually causes Sheldon to find his later spot on the couch. When Leonard returns to make some rocket fuel for Howard, Sheldon points out that he made a mistake in the fuel formulation, and the botched rocket fuel prematurely activates. Leonard thinks he has plenty of time, but Sheldon saves his life by deducing that it is likely to explode quickly, and resolves the situation by sending it down the otherwise empty elevator. Leonard explains that the reason he puts up with Sheldon is that he saved his life and did not notify the authorities.
When Penny questions Leonard's responsibility for the experiment that resulted in the destroyed elevator, he asks her what she was doing at the time, and she responds that she was studying, behaving well and doing charity work, when in reality she was jubilantly celebrating with her boyfriend after her pregnancy test came back negative. Leonard then returns to the apartment and apologizes to Sheldon, but the two then immediately get into another argument when Leonard starts watching Babylon 5, which Sheldon hates.
063. “The Lunar Excitation”
The guys set up an experiment on the building's roof to bounce a laser off the moon and back to Earth using the laser reflector left by the crew of Apollo 11. On Leonard's request, Penny arrives with her new boyfriend Zack. During the experiment, Zack turns out to be extremely ignorant and dimwitted, prompting Penny to break up with him. Later that night, Penny enters the guys' apartment drunk and has sex with Leonard. The next morning, Penny realizes what she had done and leaves the apartment embarrassed. Leonard, now thinking it is routine for friends to have "meaningless" casual sex, asks Leslie and then Penny to have sex with him, and both slam the door in his face.
Meanwhile, Raj and Howard find a dating website and submit Sheldon's profile to the website without his knowledge to help him find a girlfriend. To their surprise, the dating site matches Sheldon with a woman named Amy Farrah Fowler. Sheldon initially refuses to meet Amy as he considers dating sites "hokum", but agrees when Raj and Howard blackmail him by claiming that they hid a dirty sock in the apartment. Amy bonds with Sheldon, having had an aversion to soiled hosiery and physical contact including coitus, sharing Sheldon's disbelief of dating websites and religion, and both their mothers' having similar personalities. Howard and Raj, shocked, regret what they have done.
The Complete Season Four
064. “The Robotic Manipulation”
At dinner, Howard demonstrates a robotic arm that he "borrowed" from the Jet Propulsion Laboratory by unpacking dinner. Later at home, he uses the arm as a massager and even tries to use it to masturbate, but executes the wrong program and gets his genitals stuck to the arm, forcing him to call Leonard and Raj for help. They take him to the hospital (along with the arm and Howard's laptop containing the program for the arm movement) where the nurse turns off the laptop, which releases the arm's grip on Howard's genitals. Later Howard calls Leonard, saying it "happened again", indicating that he again tried to use the arm to masturbate and got his genitals stuck for the second time.
Meanwhile, Penny comes to know of Sheldon's new friend Amy and is shocked when Sheldon announces his plans to conceive a child with her via in-vitro fertilization based on their superior genetics using Penny as a surrogate. Penny suggests that he should first go out with Amy on a date. Since Sheldon cannot drive, and because the date was Penny's idea, she is forced into giving Sheldon a ride and ends up chaperoning. During the drive and at the restaurant where they are having dinner, Penny tries to make Sheldon and Amy have a proper conversation, as it is a first date for each of them. All her attempts fail and to add to her annoyance, Sheldon calculates the number of dates that Penny has had in her life, and the number of sexual partners she has had. Amy then asks Penny whether she ever felt like a "slut". Penny denies it, but appears unsure. When Sheldon and Penny return home later that night, Penny, who is still upset with Sheldon's claim that she had sex with 31 men, threatens to tell his mother about his procreation plans, causing him to drop them.
065. “The Cruciferous Vegetable Amplification”
Sheldon's estimate for his life expectancy leads him to the conclusion that he will miss by only a few years "the singularity, when man will be able to transfer his consciousness into machines and achieve immortality". He therefore changes his diet by eating cruciferous vegetables instead of pizza on Thursdays and decides to go jogging with Penny in the mornings in hopes of extending his life expectancy. Due to the diet of cruciferous vegetables he has a bad case of flatulence and he tumbles down the stairs while going down for his jog, Sheldon builds a robotic replication of himself which he calls a "Mobile Virtual Presence Device" (the telepresence robot by Willow Garage[3]) that would go through all the hazards of life that Sheldon would otherwise have to endure, while he stays behind in a "secure, undisclosed location" (his bedroom). The guys dismiss the MVPD as a stunt (Penny calls it Shel-Bot). Leonard then goes over to Sheldon's room to convince him to drop the idea, but Sheldon refuses to listen to him and proceeds to cite Section 74C of the Roommate Agreement requiring Leonard to assist him (by providing him transportation) "in the event one of the roommates becomes a robot". Leonard reluctantly takes the MVPD to work, completely regretting it after the MVPD continuously irritates him during the drive. Later Leonard takes the MVPD to the Cheesecake Factory for dinner. Sheldon, from his bedroom, spots Steve Wozniak having dinner there and sends the MVPD over to his table, telling him that he has a 1977 Apple II. Wozniak says that if Sheldon had the Apple II there he would sign it. Sheldon then takes the Apple II and rushes out of his apartment, but trips and falls down the stairs, breaking the Apple II and his ankle. The episode ends with a now bedridden Sheldon using the MVPD to force Penny to sing "Soft Kitty" to him.
066. “The Zazzy Substitution”
Sheldon and Amy are very compatible with each other, as evidenced by how well they can play "counter-factuals", a game they invented requiring them to know what the other is thinking when answering a question about "an alternate world that differs from ours in one key aspect" (Leonard fails miserably when he attempts to play this game). However, Amy's presence does not go down well with the other guys, who already find it difficult to handle Sheldon himself, and they start hanging out at Penny's apartment to escape "ShAmy" (the name the guys and Penny gave for the couple). But one day at lunch, Amy belittles Sheldon's occupation as a theoretical physicist relative to, in her opinion, her superior occupation of neurobiology, prompting Sheldon to terminate their friendship. Following the breakup (or according to Sheldon, "our friendship outlived its utility"), Sheldon adopts 25 cats as a substitute for Amy. A worried Leonard calls Sheldon's mother, who rushes over to the apartment. She calls over Amy and, using reverse psychology, she makes Sheldon offer to reconcile with Amy, which she agrees to after a negotiation on the amount of responsibility Sheldon has to accept for the breakup. The episode ends with Sheldon and Amy giving away $20 to anybody willing to adopt a cat.
067. “The Hot Troll Deviation”
The guys run into Howard's ex-girlfriend Bernadette while having dinner at the Cheesecake Factory. Though Howard hides under the table when he sees Bernadette, the incident nonetheless reignites his feelings for her. He seeks help from Penny, who agrees on the condition that he reveal the reason behind his breakup. He confesses that Bernadette caught him engaging in cybersex with a fellow World of Warcraft player, who is later revealed to be one of Howard's male colleagues at Caltech. Howard and Bernadette later meet at the Cheesecake Factory and after Howard reveals the reason he indulged in cybersex (he thought that Bernadette was not interested in having sex with him), they make amends and decide to give their relationship another try. They go out on a date, following which they make out in Bernadette's car.
Meanwhile, Sheldon and Raj argue over the latter wanting a desk in their office, with Sheldon citing budgetary reasons (saving money for a drawer full of Red Vines, a marshmallow shooting rifle, and a super executive ant farm with glow-in-the-dark sand) for not providing a desk. Raj offers to buy his own desk, to which he reluctantly agrees. When he enters his office later, he sees Raj sitting on a huge and ornate desk which takes up half the office space. After Raj refuses to obey Sheldon's subsequent order that he remove the desk, a series of annoying confrontations (Sheldon calls it "tit-for-tat" exchanges) ensues between the two. Eventually, Sheldon prepares ammonia and hydrogen sulfide to create a bad smell in order to throw out Raj from their office, which Raj tries to counter by lighting his cinnamon-apple-scented aromatherapy candles. However this makes the gases ignite, causing an explosion.
068. “The Desperation Emanation”
When Amy decides to introduce Sheldon to her mother, he becomes worried as being introduced to Amy's mother would indicate that Amy wants to be his girlfriend. So he begins to avoid Amy, removing all possible contact with her and even disguising himself so that she would not recognize him. However Amy catches Sheldon outside the apartment building and then tells him that she only wants to introduce him to her mother so that she would be convinced that Amy is in a relationship and leave her alone. Later when talking to Amy's mother on webcam, a now relieved Sheldon and Amy lie to Amy's mother that they are in a "sexual relationship", which does not go too well with her.
Meanwhile, as Howard now has a girlfriend, Leonard decides to invoke the "Girlfriend Pact" (from the Season 3 episode The Creepy Candy Coating Corollary) with Howard. Howard and Bernadette set up a double date with Leonard and one of Bernadette's friends, Joy. Joy behaves in an obnoxious and inappropriate manner during the date, which disgusts Leonard. However he later accepts another date with Joy due to understanding that sex is a strong possibility.
069. “The Irish Pub Formulation”
Raj's younger sister Priya, a lawyer by profession, visits Pasadena en route to Toronto. Though unknown to the others including Raj, Priya had been involved in a sexual encounter with Leonard five years earlier, despite Leonard's assurance to Howard that he would never hit on Priya in deference to Raj. That night, Priya sneaks into Leonard and Sheldon's apartment unknown to Sheldon and has sex with Leonard. Sheldon finds out the following morning that Leonard and Priya had "coitus" and frames an elaborate, flawless lie to cover it up, which involves Leonard having had sex with an imaginary Irish bartender named Maggie McGeary. But Leonard decides not to hide the truth and confesses to Raj that he slept with Priya. Raj is initially upset, but reconciles with Leonard after he says that Priya broke his heart. The guys then unleash confessions of all of the deceptions they have perpetrated on each other, including Howard dropping Raj's iPhone into a urinal, Sheldon's experiment feeding moth parts to Leonard mixed in his food and Raj using Sheldon's toothbrush. Sheldon becomes upset at Raj for using his toothbrush and terminates his friendship with him, but immediately forgives him after Raj reveals that he gave him a talking Thomas the Tank Engine with real puffing smoke for Thanksgiving.
070. “The Apology Insufficiency”
Howard needs top-level security clearance to work on a government surveillance satellite, so the FBI sends Agent Angela Paige to interview Leonard, Sheldon and Raj in order to do a background check on him. None of the guys are able to convince Agent Paige that Howard is trustworthy; Raj fears being deported back to India, while Leonard unsuccessfully tries to ask her out by seeming "confident". Sheldon on the other hand, unwittingly tells her that Howard crashed the Mars Rover (from the Season 2 episode The Lizard Spock Expansion). As a result, Howard is denied clearance. Sheldon feels guilty that he caused Howard's career to be set back and apologizes to Howard, who refuses to accept it. Later when Sheldon discusses the issue with Penny, Penny refers to an incident from Star Trek (where Captain Kirk won the Kobayashi Maru by reprogramming the simulator), which inspires Sheldon to use neurolinguistic programming to modify Howard's thoughts to force him to accept his apology. That too does not work, so as a last resort, Sheldon offers Howard his spot on the couch. Howard is touched at this gesture and forgives Sheldon. The episode ends with Sheldon taking back his spot after only 94 seconds.
071. “The 21-Second Excitation”
The guys decide to go to a special midnight screening of Raiders of the Lost Ark which has 21 seconds of unseen footage. However when they arrive at the theater, they are made to wait in a long queue, making Sheldon whine about how Leonard, Howard and Raj wasted time by having dinner. Later Wil Wheaton arrives and is immediately allowed entry without having to stand in a queue due to his celebrity status, which angers an already-impatient Sheldon. Eventually the guys are barred from watching the movie as the theatre is fully occupied. Just as the four are about to leave, Sheldon discovers a side door and enters it. Leonard, Howard and Raj follow Sheldon and find him holding some film cans, having stolen the reels of the movie in retribution for being denied from watching the movie. Wheaton too finds Sheldon holding the movie reels, leading to a mob of angry Raiders (and Wheaton) chasing the four from the theater, mimicking the opening scene of Raiders of the Lost Ark.
Meanwhile, Amy decides to spend the evening with Penny and Bernadette, who are planning a "girls' night", despite her initially planning to go with the guys to Raiders of the Lost Ark. As Amy had never been to a girls' night before, she grosses out Penny and Bernadette with descriptions about her female parts as she thinks that is what girls talk about and looks up Wikipedia to determine sleepover customs, which Penny and Bernadette reluctantly go along with. During Truth or Dare, Amy and Bernadette get on Penny's case about Leonard. Annoyed, Penny storms off to her bedroom. Later Amy finds out that girls engage in lesbianism during sleepovers and enters Penny's bedroom. The episode ends with a horrified reaction from Penny, indicating that Amy may possibly be trying to indulge in lesbian sex with her.
072. “The Boyfriend Complexity”
Penny informs Leonard that her father Wyatt has come on a visit and asks him to pretend that they are back together as he is the only boyfriend she had that her father ever approved of. He is initially wary of the idea, but gleefully plays along to get her to confess (he also calls her out on her hypocrisy at being mad at him for going along with her stupid, flawed plan), which she does when he is Wii fishing with her father. Penny's father confronts her about the hoax and admonishes her for always being dishonest to him. After Penny goes to her room, her father pleads with Leonard to get back together with her because he does not want her to go back to dating boyfriends whose personalities he does not approve of and wants grandchildren who do not grow up in a mobile home. Leonard then plays along as Wyatt pretends to angrily throw him out of Penny's apartment.
Meanwhile, Howard and Raj decide to spend the night in a control room so that Raj can control a ground-based telescope located in Hawaii in the hope of seeing the star Epsilon Eridani dim, which would be evidence of a planet orbiting it. Raj becomes angry when Howard invites Bernadette until he discovers that Bernadette brought wine. A drunk Raj complains that no girl wants to kiss him, to which Bernadette shows sympathy for him. At this, Raj attempts to kiss her, but ends up kissing Howard when he attempts to stop Raj from kissing his girlfriend. The next day, Howard and Raj act awkward around each other and lash out at Leonard and Sheldon when they enquire about what they had seen on the telescope.
Elsewhere, Sheldon thinks that Leonard and Penny have got back together (he is unaware they are faking it). So he modifies the Roommate Agreement to include a Penny-specific section which addresses some of Penny's annoying habits, which if she does while at their apartment, would cause Leonard to pay a fine to Sheldon. When Leonard tells him later that he and Penny "broke up" again, a frustrated Sheldon throws the agreement papers into the air and yells whether Leonard even thinks of other people.
073. “The Alien Parasite Hypothesis”
While on a girls' night out with Penny and Bernadette, Amy meets Penny's ex-boyfriend Zack and immediately becomes attracted to him. She later discusses her symptoms with Sheldon (elevated heart rate, moist palms, dry mouth, vascular throbbing in the ears and genitalia and saying an involuntary "hoo" in Zack's presence) and comes to the reluctant conclusion that she is sexually aroused by Zack. It is also pointed out that Sheldon might be jealous. Sheldon prefers to assume that Amy has contracted an alien parasite. Later when Sheldon discusses about Amy and Zack with Penny, Penny tells him that there is "something" he could do about Amy's "urges", but as usual he misunderstands what Penny is trying to say to him (Penny meant that Sheldon should show romantic feelings to Amy) and instead tries to bring Amy and Zack together. He manages to contact the right Zack Johnson and sets him up on a date with Amy at a bar. This proves to be a failure, as Amy finds out that Zack is extremely stupid. Later while walking home with Sheldon, Amy does something she never did before- she holds Sheldon's hand. When Sheldon asks why Amy is holding his hand, Amy says it is just an experiment, but then lets go and says, "Nope. Nothing. Never mind.", indicating that she is not attracted by Sheldon's appearance, yet chose Sheldon's intellect over Zack's looks.
Meanwhile, after one of the scientists at the biology lab is bitten by a radioactive rat, Howard and Raj argue about who would be the better superhero (with Raj expressing his desire to be "Rat-Man"). Knowing that Raj is afraid of spiders, Howard proposes a contest where the first person who dares to put his hand into a jar with a huge spider in it and keeps it there for the longest time gets to be the superhero. This however backfires, as the spider crawls onto Howard's arm, freaking him out. The duo decide to settle their argument once and for all by having a wrestling match, but this too fails as instead of wrestling each other, they only end up circling and insulting each other.
074. “The Justice League Recombination”
Penny gets back together with Zack. The guys insult Zack's low intelligence which upsets him; however he reconciles with the four after Sheldon offers him Milk Duds and he accompanies them to the comic book store, where Stuart announces the New Year's Eve costume party. The guys decide to come as the Justice League of America and also decide to include Penny as Wonder Woman (who initially refuses, but later agrees) and Zack as Superman (because according to Howard, "he is the only person we know with actual muscles"). Leonard dresses up as Green Lantern, Sheldon as The Flash, Howard as Batman and a reluctant Raj as Aquaman. Sheldon forces Penny to wear a black wig, as Wonder Woman has black hair, but Penny refuses to wear the wig and decides not to come to the costume party. Sheldon, Howard and even Zack are unable to convince Penny to change her mind. Later when Leonard talks to her in an attempt to convince her to come to the party, Penny reveals that she got back together with Zack only because she did not want to spend New Year's Eve alone. She confesses that she'd rather go to a regular party with Zack than to a costume party with Leonard. Leonard questions why not him, prompting Penny to change her mind and put on the wig. At the comic book store, the group win the award for the Best Group Costume. The episode concludes with the six witnessing an ongoing car theft and then scurrying off despite wearing Justice League costumes.
075. “The Bus Pants Utilization”
Leonard gets an idea to develop a smartphone app that will allow users to solve differential equations just by taking a picture of them. However, Sheldon catches the heat from Leonard when he tries to put himself in charge despite the app being Leonard's idea (Sheldon had named himself as the chief executive, financial, and operating officers among other high-rank positions while listing Leonard as only the founder). Despite eventually acknowledging Leonard as the leader of the project, Sheldon continually criticizes Leonard's leadership in the development of the app. After Sheldon suggests names for the app that have his name in it (the "Surprisingly Helpful Equation-Linked Differential Optimized Numerator", which has "Sheldon" as its acronym, and "Project NodlehS", which has "Sheldon" spelled backwards), Leonard tells him to stop. Sheldon abruptly calls for a vote to change the team's leadership, resulting in Leonard kicking Sheldon off the team. After unsuccessfully trying to bribe Howard and Raj to dump Leonard and join his "rival company", Sheldon resorts to sabotaging Leonard's project by playing a theremin while they work, and Leonard kicks him out of the apartment in retaliation. When Penny sees Sheldon moping on the stairs, she sympathetically invites him to her apartment for a cup of cocoa, but quickly regrets her decision. She asks the guys to take Sheldon back, promising that he will apologize. Sheldon initially refuses to apologize, so Penny tells him to use sarcasm to disguise his lack of sincerity, an idea to which Sheldon immediately takes a liking. The guys agree to put him back on the team, but Sheldon quickly goes back to criticizing their work, demanding that they completely start over. The episode ends with Sheldon, having been kicked off the team again, reluctantly working with Penny on an app she mentioned to him while sitting on the stairs- the app identifies shoes and finds out where to buy them.
076. “The Love Car Displacement”
Amy asks Penny to join her, Bernadette and the other guys on a trip to a science conference in Big Sur, California, as she believes them to be her best friends. At first she rejects the offer, but then accepts after learning about the free spa treatment. Before they leave, Sheldon ("travel supervisor") explains the timetable and seating arrangements. Amy convinces Sheldon to let Penny ride in the lead car with themselves and Leonard because her "Nebraska backwoods skills" could help them if their car breaks down. During the trip, Penny gets sent to the second car with Howard, Raj and Bernadette after she attempts to stand up to Sheldon. At the hotel, Bernadette spots Glenn, her professor at college and ex-boyfriend, a tall handsome guy who intimidates Howard. When Howard confronts Bernadette over Glenn, she gets mad at him and decides to stay with Amy and Penny. Since there are only two beds and Penny cannot sleep because of Amy's nightmares (which cause her to bite), Penny moves out of her room and asks Leonard if she can stay with him and Sheldon. Leonard accepts, but after Penny tells him that they aren't going to have sex, Sheldon wakes up, asking them if they are not going to have "coitus". As he receives different answers (Penny says "yes", Leonard says "no"), Sheldon leaves and seeks shelter in Raj's room, where Raj is about to watch Bridget Jones's Diary. Sheldon eventually kicks out Raj, who then goes to Leonard and Penny's room, just when they are about to have sex. He crawls into the bed vacated by Sheldon, stopping Leonard and Penny from having sex. The next morning as Sheldon, Leonard, Howard, Raj, Bernadette and Amy sit on a panel, with Penny in the audience, they all exchange (initially thinly veiled) criticisms at one another stemming from the previous night's events. An irritated Penny then accepts a ride back to Pasadena with Glenn, much to Leonard's horror. Later while returning home, Leonard gets pursued by the police for speeding as he is distracted by the thought of Penny being with Glenn.
077. “The Thespian Catalyst”
Sheldon guest lectures at a university, but his teaching style is considered boring and intolerable, and results in negative online feedback from his students. On Amy's advice, he decides to take acting lessons from Penny for $40 to learn how to more easily communicate with his students, though his attitude during the lessons frustrates Penny. Finally, they act out a Star Trek fanfiction script which Sheldon wrote in his childhood, in which Mr. Spock takes a young Sheldon to the 23rd century to bring hope and peace to the galaxy. Penny plays the role of Spock as she feels that Sheldon needs to come out of his comfort zone, while Sheldon plays the dual role of himself and his mother. However while acting out the script, Sheldon immerses himself so deeply in the part that he is brought to tears, because he does not want to be taken away from his mother by Spock. Penny then calls his mother and gives the phone to Sheldon so that his mother can console him.
Meanwhile, Raj develops a crush on Bernadette after she comforts him over not having female company. He starts daydreaming various scenarios involving him and Bernadette; the first one is Howard asking him to satisfy Bernadette's sexual needs while he is away on a fellowship in Israel; the second one is a dying Howard, who has met with a fatal accident, asking him to take care of Bernadette and satisfy her sexually after his death; the third and final one has him and Bernadette dancing Bollywood-style.
078. “The Benefactor Factor”
President Siebert invites the guys to a fundraiser for Caltech that Saturday. While Leonard, Howard and Raj are willing to attend, Sheldon refuses to go and stays back in the apartment; however, he changes his mind after a video chat with Amy, who tells him that if he is not at the fundraiser, the task of raising funds for the physics department would fall to Leonard and Raj, whom, according to her, would probably fail in raising funds, as a result of which the funds would go to departments like geology and liberal arts; but during the fundraiser, he insults many donors by refusing to shake hands with them due to his mysophobia as a result of which the physics department loses potential donors. At the fundraiser, the guys are introduced to Mrs. Latham, an elderly philanthropist whose condescending attitude terrifies them, but she later tells Leonard that she likes making smart people nervous. She then invites Leonard to dinner the following night to talk more about his research, despite none of the guys (including Leonard) feeling like they did anything right at the fundraiser. During dinner, she reveals that she is willing to donate money to the physics department on one condition- Leonard must have sex with her. Leonard is not comfortable with this and is unwilling to prostitute himself, despite Sheldon's plea that he do it for the physics department. The next night, Leonard again has dinner with Mrs. Latham, during which she tells Leonard that whether he has sex with her or not, she will donate to the physics department. After this, she flirts with him, eventually causing him to give in and have sex with her. The next morning, Penny and Sheldon catch him as he arrives home after his "walk of shame" and tease him slightly. Later at work, he is applauded by everyone at Caltech, including Howard, Raj and President Siebert for his "gigolo work" which brought funds to the physics department.
079. “The Cohabitation Formulation”
Bernadette is upset because Howard always goes home after sex so that he can help his mother in the morning. She insists that Howard moves in with her, which Howard is not interested in until he has a big fight with his mother after reaching home regarding his sexual activity with Bernadette. After spending the rest of the night in Leonard and Sheldon's apartment, Howard moves out of his house to Bernadette's apartment. Both are happy initially, but later Bernadette realises that Howard is too dependent on his mother and insists that he should not expect the same treatment from her. As a result, Howard returns home, where his mother (who did not know that Howard had moved out) grounds him for "running away".
Meanwhile, after Howard offhandedly mentions that Raj's younger sister Priya has come to Pasadena and is staying at Raj's apartment, Leonard rushes over there to talk to her. Leonard and Priya then decide to pursue a long-term relationship much to Raj's indignance, who even quotes from the Manusmriti to dissaude Priya from dating Leonard, only for Priya to remind him that he eats beef which is also forbidden in the Manusmriti. Amy, who considers Penny her BFF, rushes over to Penny's apartment to console her when she hears the news, but Penny insists that she is not upset that Leonard and Priya are dating. Later while having dinner, Penny finds out that Priya, being a lawyer, is much more successful than her and also sees that Leonard (and even Amy) is crazy about Priya's achievements. After returning to her apartment following dinner, Penny breaks down crying, which confirms that she still has feelings for Leonard. Amy, who is also in Penny's apartment, comforts her before using electrodes to determine which brain regions are active during crying, as she plans to make a rhesus monkey cry by stimulating the analogous areas of its brain. During the weekend, with Leonard and Priya having gone to Santa Catalina Island, Howard grounded by his mother and Raj at home in strong disapproval of Leonard and Priya dating, Penny spends her time with Sheldon and Amy (via webcam), who tells her that thanks to her contribution, she was successfully able to make a rhesus monkey cry.
080. “The Toast Derivation”
Now Leonard and Priya are dating and since she lives with Raj, Leonard and Howard decide to have dinner there instead of the normal venue which disturbs Sheldon who prefers their place. Sheldon leaves and stops by the Cheesecake Factory where Penny tells him he has to accept that the gang will be hanging out at Raj's place more often. Amy tells him that Leonard is the nucleus of their social group and not Sheldon. As a result, he sets up a new group consisting of Kripke, Stuart, Zack and LeVar Burton (whom he tweeted) with him as the nucleus. Sheldon's plans are dismissed by the others in favor of Zack's dating stories and getting drunk and singing karaoke. Naturally, Sheldon does not like that very much, so he decides to go back to his old friends, who, in the meantime, realized that they actually missed Sheldon. In the end, LeVar Burton finally does show up at Sheldon's place, but when he sees Kripke, Stuart and Zack singing karaoke together, he leaves immediately, stating "I am so done with Twitter".
Meanwhile, Bernadette and Amy want to take Penny out dancing to get her mind off of Leonard and Priya. She agrees to come with them on the grounds that they stop pestering her about Leonard and Priya. As she changes clothes, she tells the girls that it is the first time in her life she is satisfied with being single and does not want to have sex with a random guy to make up for it, however when Amy finds the snowflake that Leonard gave to her after his expedition to the North Pole, she changes her mind as her feelings for Leonard come back to the surface again.
081. “The Prestidigitation Approximation”
Priya has begun to dominate in her relationship with Leonard, buying him new clothes and forcing him to wear contact lenses (which Leonard is not comfortable with). She also feels threatened by Leonard continuing to hang out with Penny, even though they have broken up, so during sex, she tells him to break all contact with Penny. Leonard initially hesitates, but still tries to tell Penny to stay away from him, albeit indirectly, with an obscure anecdote about Charles Darwin's finches. Penny does not get the right message, but Leonard takes comfort in the fact that he tried. Later Penny interrupts Leonard's date with Priya and is completely oblivious to what is going on. Leonard once again indirectly tries to tell Penny to stay away from him, but this time Penny gets the message and realizing that Priya was behind this, decides to break all contact with Leonard. Leonard immediately attempts to go after his ex-girlfriend, only to crash into the doorframe due to his uncomfortable new contact lenses.
Meanwhile, Howard shows Sheldon, Raj and Penny a card trick in which a volunteer picks a card and after shuffling the deck, Howard tells the volunteer his/her card. Raj and Penny both try out the trick and are amazed by it. Though at first his attitude is dismissive, Sheldon eventually becomes obsessed with discovering the trick's secret, as even Penny could figure it out. He goes to the extent of using a barcode reader and even hacking the Oak Ridge National Laboratory's Cray supercomputer, attempting to procure Uranium 235 on Craigslist in order to recreate the trick. It is then revealed (to the audience) that the card trick is just a prank played by Howard, Raj and Penny on Sheldon. Raj and Penny willingly pretended that Howard was successful, knowing fully well that Sheldon would go nuts trying to figure out the trick's secret. When Sheldon wants Howard to perform the trick on him in the end, Raj manages to get a peek on Sheldon's card and uses hand signals to tell Howard the right answer. Sheldon is puzzled once more, still not knowing that he had been pranked all along, while Howard and Raj both laugh gleefully.
082. “The Zarnecki Incursion”
Sheldon's World of Warcraft account has been hacked and all of his WoW stuff have been stolen. He enlists the help of the other guys in finding the hacker. Howard manages to trace the hacker and reveals that his name is Todd Zarnecki and lives in Carlsbad. The guys then drive to Carlsbad to get back Sheldon's WoW stuff. At Todd's home however, not only does Todd refuse to return Sheldon's stuff, but he also takes away Sheldon's Klingon Bat'leth. Defeated, the guys decide to return home, but their car breaks down midway, prompting Leonard to call Penny to fetch them. When Penny hears their story, she drives them back to Todd's house where she delivers a kick to Todd's groin and forces him to return Sheldon's stuff.
Meanwhile, Amy, Bernadette and Penny criticise Priya and her arrogant, dominating behavior, with Amy going to the extent of asking Bernadette and Penny to "throw their waste" at Priya. Penny takes Amy's comments lightly, but after an encounter with Priya in the apartment lobby, she agrees with Amy.
083. “The Herb Garden Germination”
Penny spreads a rumor that Bernadette is thinking of breaking up with Howard. Amy tells Sheldon, who tells Leonard, who tells Priya, who later tells Raj. Priya informs Leonard that Raj has a crush on Bernadette and even writes poems about her. When Raj hears the rumor from Priya, he gets excited, as he could finally have his own shot with Bernadette. Howard is completely unaware of the rumor and plans to ask Bernadette to marry him. The others try to stop him from asking, as they believe that Bernadette will reject him and he will become blindsided, except Raj, who selfishly encourages Howard to go through with his plan in the hope that Bernadette will reject him. When having dinner one night, Howard pulls out the proposal ring, as he cannot imagine a better time to ask her than with all of his friends around. Despite the protest of the others, he gets on his knees and starts to talk. At that moment, Bernadette cuts him off in what appears to be a rejection, however she actually accepts his marriage proposal, devastating Raj.
The rumor about Bernadette breaking up with Howard motivates Amy and Sheldon to conduct an experiment in which they concurrently spread two false rumors: a "tantalizing" one (Sheldon and Amy had sex) and a "non-tantalizing" one (Amy decided to start a herb garden) to see which rumor gets back to them first. Amy starts both rumors by informing Penny and, as expected, the rumor about the two having sex reaches the entire group in under 24 hours while the other one is not mentioned again. When Howard's proposal distracts the group from the rumor, they decide to start over with their experiment. Amy visits Penny (who just got a text from Bernadette informing her about the proposal) again and tells her that she is getting orthotics and that she is pregnant with Sheldon's baby. Moments later Leonard meets Amy in the hall after he receives a text message from Penny, informing him about the false pregnancy. He confronts Amy, who, in return, just wonders "is there anything on there about orthotics?".
084. “The Agreement Dissection”
When Leonard takes a shower with Priya while Sheldon experiences an event of force majeure, he gets charged with two violations of the roommate agreement (Leonard denied access to the bathroom when Sheldon had to urinate and Leonard was not the only person in the shower). However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges, due to the agreement's vague wording, much to Sheldon's dismay. When the guys take advantage of Priya's skills in order to eat Greek food (which Sheldon does not like at all) on pizza night, Sheldon seeks shelter at Penny's, who invites him to join her on a girls' night out with Amy and Bernadette. After the girls have some cocktails and Sheldon mentions he had learned to dance at cotillion balls as a child, they decide to take Sheldon dancing. After dancing, Sheldon takes an intoxicated Amy back to her apartment. Amy tells Sheldon not to give in to Priya's law skills, just like a monkey would defend his territory. She then proceeds to kiss him and then rushes to her bathroom to vomit. The next day, Sheldon presents an overhauled version of the roommate agreement to Leonard and asks him to sign it. When Leonard shows his reluctance, Sheldon activates a "self-destruct sequence" on his laptop; If Leonard does not sign the agreement within a minute, an e-mail will be sent to Priya's parents informing them of their relationship. Leonard accuses Sheldon of bluffing and blackmailing and does not see any harm in Priya's parents knowing. Priya, however, knowing that her parents do not approve her dating an American, tells Leonard their relationship is over if he does not sign the new agreement. After a failed attempt to cut the power supply from Sheldon's laptop, Leonard gives in and Sheldon aborts the program. Later that day, Sheldon speaks with a hungover Amy via webcam and thanks her for the advice that she gave him the night before. They agree to treat their relationship like a "crashed computer" and "restore" it to the last point it worked for both, thus deciding to forget about the entire evening's events. Meanwhile, Leonard, not knowing how strict Priya's parents are, argues with her about whether or not she is ashamed of him.
085. “The Wildebeest Implementation”
While shoe-shopping with Penny and Amy, Bernadette reveals that Howard and her have been invited to a double date by Priya. Amy suspects that Priya is trying to win over the weakest member of their social group, just as a cheetah attacks the weakest specimen in a herd of wildebeests. Therefore, she proposes to use Bernadette to spy on Priya and spread disinformation about Penny and Leonard. Bernadette is uncomfortable with lying, as she went to a catholic school, but nonetheless goes along with the plan. When the four meet for dinner, Priya makes a snide remark about Penny's acting career. Penny and Amy order Bernadette to tell Priya and the others that Penny is on her way to Prague for a movie part and that she is dating an architect (although this is AutoCorrected to astronaut). Priya, Leonard and Howard begin to ask questions about this news (being very interested in details about where Penny met the astronaut), to which Bernadette has to improvise answers, increasingly unnerving and frustrating her. Bernadette excuses herself to the bathroom and calls Amy to tell her that the lie (as well as her calm) is unraveling. She also reveals that Priya and Leonard are planning a trip to India to meet the Koothrapallis. Consequently, Penny wants her to find out if the two are getting engaged. Bernadette finally snaps and storms out, leaving Priya and Leonard befuddled.
Meanwhile, Raj, who is still very lonely and does not want to be the "fifth wheel" during the double date, visits Sheldon in his apartment. He tries to get advice about whether or not he should try to cure his social anxiety using an experimental drug, however Sheldon is preoccupied with his "three-person chess" project, as he does not only adapt the popular game for 3 players with a new board design, but also adds new chess pieces. Sheldon finally advises Raj to do so and accompanies him to a coffee shop to observe the drug's effectiveness. It ends up working very well, as Raj starts to talk to a woman named Angela, who also seems to like him. However, an adverse effect begins to manifest itself, causing Raj to lose all his inhibitions and strip completely naked, thus scaring off Angela. In the end, Sheldon, Leonard and Howard play a test game of Sheldon's chess version, to which he added a multitude of new chess pieces and rules while a still-nude Raj is watching them.
086. “The Engagement Reaction”
While dining at the Cheesecake Factory, Bernadette and Howard reveal that their parents have not been informed about their engagement yet. Howard arranges a lunch for his fiancé and his mother and they end up getting along well. After Howard hears the good news while talking to his mother, who is in the bathroom, he decides to make the move and tell her about the engagement. To his horror, she collapses from an apparent heart attack. Howard takes her to the hospital as fast as he can. When the others hear about this, they rush to the hospital. Sheldon, being extremely mysophobic, is initially reluctant to visit the hospital and only agrees to come after Penny pressures him to go. When Bernadette finds out that Howard was telling his mother about his engagement before she collapsed, she is very upset, as she believes that she is the reason all this happened. When Mrs. Wolowitz finally wakes up, the doctor informs them that it had not been a heart attack and that she wants to see Bernadette before anyone else. It is revealed that she actually had food poisoning from the restaurant she and Bernadette ate at and was worried about Bernadette's well-being, whom she actually likes a lot. Bernadette ends up being very mad at Howard, as he led her to believe that it was all her fault.
While in the hospital, Priya and Penny start searching for the cafeteria and bond in the process. They mainly discuss Leonard's skills in the bedroom. Sheldon has other things to worry about, as he tries to avoid contact with anything in the hospital and, when he has to go to the restroom, is trapped in there, waiting for someone to open the door for him. When he tries to avoid a coughing patient on the way back, he seeks shelter in a random room. Much to his horror, it turns out to be a bio-hazard room, where he is exposed to a deadly disease. Sheldon is eventually forced to stay in the hospital under a 2-week quarantine after the exposure, with his friends keeping him company in hazmat suits.
087. “The Roommate Transmogrification”
Bernadette announces that her dissertation has been accepted, earning her a Ph.D. and a well-paid job, Later Bernadette decides to buy Howard an expensive Rolex watch as a present and tells him to "let her worry about the money", a comment that disturbs Howard. Meanwhile, Leonard's and Priya's noisy sexual encounters sends Raj to spend the night at Sheldon's apartment. When Leonard finds him in his bed, he proposes that Raj moves in with Sheldon until Priya finds her own place. Raj likes the idea, signs Sheldon's roommate paperwork and moves in with him. He then prepares a fancy dinner for them which delights Sheldon who decides Raj is a much better roommate than Leonard. Penny stops by, stays for dinner and the both of them get drunk from the wine Raj served. Penny confesses to Raj that she "screwed up", as she should not have broken up with Leonard, and that she would be "on" him (Raj) if they were not friends. Priya receives a video call, Leonard overhears that she is moving back to India and storms out revealing their relationship to her parents.
At the end of the episode, Sheldon discovers Leonard sleeping on their couch, just before Howard shows up and announces that he had a fight with Bernadette over the watch. Penny wakes up and is horrified when she notices Raj in Leonard's bed beside her. She tells him that last night never happened and tries to sneak out of the apartment; however, they are busted by the others. Penny just states that "it's not what it looks like" and leaves. Sheldon then asks "What does it look like?"
The Complete Season Five
088. “The Skank Reflex Analysis”
Raj finds himself in hot water with Leonard after his night with Penny and also with Howard after he discovers Raj's fantasies about Bernadette (who is also angry at Raj because of his fantasies, and now has to contend with Howard's feeling of distrust of her as a result). Raj (who now has feelings for Penny) and Penny later talk about the recent events and it turns out they did not have sex because Raj ejaculated prematurely when Penny tried to help him put on a condom. When Raj tries to arrange a date, Penny tells him that she has no romantic feelings for him and likes him only as a friend, bringing an end to his nascent crush on Penny. Nonetheless, Penny feels that this has damaged her relationship with the guys permanently and decides to move back to Nebraska, as she has not had any worthwhile acting jobs since moving to Pasadena. When she goes over to Leonard and Sheldon's apartment to apologize and announce her intention to move, she gets a call from her agent, informing her that she got a part in a hemorrhoids commercial, causing her to scrap her moving plans.
Meanwhile, after trying to figure out what Penny meant by "It's not what it looks like" (from the Season 4 finale), Sheldon appoints himself as the captain of the guys' paintball team. But when they are at one of Caltech's tournaments where they fight against other departments, their team falls apart because of Leonard, Howard and Raj's lack of enthusiasm due to the recent events. Sheldon, blaming himself, puts down his paintball gun and walks outside, mocking the rival team from the geology department. Following that, he is promptly shot several times by the geology team. Leonard, Howard and Raj immediately rush out to avenge Sheldon's "sacrifice" and even manage to claim the victory for the physics team.
089. “The Infestation Hypothesis”
Penny gets a new chair, which Sheldon enjoys until he finds out that she picked it up from the street. He becomes paranoid about the chair due to his mysophobia and constantly pesters Penny to dispose of it, to no avail. He then asks Amy to persuade Penny to get rid of the chair as she and Penny are good friends; however when she tells Penny to dispose of the chair, Penny becomes angry at Amy for allowing Sheldon to use her. Fearing that her friendship with Penny may be over, Amy sits on the chair and praises it to show her loyalty to Penny, but is then bitten by something moving in the chair, causing her and Penny to run out of the apartment screaming. Later, Raj and Howard find the chair at the curb, who decide to take it up to Leonard and Sheldon's apartment so that Raj does not end up having to sit on the floor. As they pick it up something can be seen by the camera crawling around inside.
Meanwhile, Leonard begins a long distance relationship with his girlfriend Priya, who has returned to India, via Skype. On Howard's advice, he decides to engage in cybersex with her. However he does not know how to do cybersex, prompting Priya to guide him, but his laptop screen freezes when Priya begins to take off her shirt. With his first attempt at cybersex having failed, Leonard again seeks advice from Howard, who asks him to kiss Priya through the laptop screen. He prepares to perform this when he attempts cybersex with Priya again, but this attempt also fails as Priya's parents are sitting beside her.
090. “The Pulled Groin Extrapolation”
Sheldon goes to the model train store to hear a lecture on HO gauge model trains, and is convinced into buying an HO gauge model train set. However he later starts to enjoy playing with it and eventually buys a N gauge model train set which is much smaller than an HO gauge model train set.
Amy decides to take Leonard instead of Sheldon as her date to a wedding for two scientists from the primatology department as Sheldon behaves like a child during weddings. At the wedding, Leonard is feeling upset about the state of his relationship with Priya, to which Amy retorts that she is trying to have a good time even though Sheldon is at home playing with model trains. She then gets Leonard to dance with her. When Amy drops Leonard home later that night, it is revealed that Leonard had pulled his groin while dancing, which was eased by ice given to him by Amy. Nevertheless, he feels that he enjoyed the evening and kisses Amy on the cheek, prompting her to think that he has fallen in love with her. She sends an e-mail to him the following morning to clarify that she does not have feelings for him. When Leonard tells Sheldon that he had a great time with Amy, even though his groin hurts as a result, Sheldon, who incorrectly thinks that they had sex, hits him on the shoulder and angrily retorts "She is not for you. Not for you!" indicating that he has feelings for Amy.
Meanwhile, Howard and Bernadette's relationship hits a snag when Bernadette tells Howard that she would not move in with him and his mother after they get married. Howard asks her to stay with him and his mother for the weekend as a "trial", to which she agrees. However during her stay, she is horrified at certain aspects of Mrs. Wolowitz's behavior and her relationship with Howard. The next morning, she reveals to Howard that she is trying to get along with his mother, despite being entirely different people. While giving Howard breakfast in bed, she launches into a back-and-forth series of exchanges with Mrs. Wolowitz in which Bernadette imitates her voice and accent perfectly.
091. “The Wiggly Finger Catalyst”
Penny sets up Raj on a date with her deaf friend Emily, for whom his selective mutism is no longer an issue. Both take a liking to each other immediately after they meet, though Raj needs Howard as a translator at first as he does not know sign language. It soon turns out that Emily is exploiting Raj for his wealth (according to Sheldon, Raj is "Richie Rich rich", a fact which none of the gang knew about), prompting Penny and Howard to talk to her, but when Howard indicates that she is a gold digger, she becomes very offended. Later Penny tries to talk Raj out of the relationship, but he refuses to listen to her, making her contact his parents, who threaten to cut him off unless he breaks up with Emily. He refuses to listen to them too, but when he later tells Emily that he chose love over his parents' money and decides to return all the expensive gifts he bought her, she breaks up with him. After commiserating with his friends at The Cheesecake Factory, they make Raj foot the bill as they all now know that he is extremely wealthy.
Meanwhile, Sheldon decides to use the Dungeons & Dragons dice to help him make trivial decisions so that his mind is free for more important things. Although this allows him to get some important work done more efficiently, it also results in him eating things he would not normally eat, and making odd decisions such as growing a mustache.
092. “The Russian Rocket Reaction”
Howard is ecstatic to learn that he will be traveling to the International Space Station as a payload specialist to assist in the implementation of a deep space telescope designed by his engineering team. However the news does not go down well with Bernadette, who is upset that he did not consult her first and fears for his safety. She tattles on him to Howard's mother (Howard had not told his mother yet that he is going to space), who forbids him from going to space. Howard becomes upset and begins to reconsider his relationship with Bernadette. After talking to Penny and Amy, Bernadette feels guilty for what she had done and decides to apologize to Howard. He forgives her, but reiterates that he will go to space, which she accepts.
Meanwhile, while Sheldon and Leonard are at the comic book store, Wil Wheaton shows up and invites them to a party at his house that Friday. Sheldon takes offence when Leonard decides to go to the party and begins to consider their friendship as "Schrödinger's friendship", in the sense that Leonard is simultaneously his friend and mortal enemy, the final outcome to be determined when Leonard does or does not go to the party. Eventually he gives in and decides to attend the party after Leonard mentions that Brent Spiner will be there. At the party, Wheaton gives him the very thing, the denial of which years ago started their enmity- a signed, mint-condition, limited-edition Wesley Crusher action figure. Sheldon immediately forgives him, gives him a rare hug and claims that he is his friend. However Brent Spiner soon becomes Sheldon's enemy when he opens the figure's mint condition packaging.
093. “The Rhinitis Revelation”
Sheldon's mother comes to Pasadena for a weekend visit while waiting to board a Christian cruise called the "Born Again Boat Ride". However she decides to spend her time eating out and going sightseeing around Los Angeles with Leonard, Penny, Howard and Raj instead of cooking and watching Sheldon embarrass a Nobel laureate. This upsets him, creating a standoff between him and his mother. When he talks about his mother's behavior to Amy, she counsels him that while he is a genius, his emotional reactions to his mother ignoring him are no different from that of any other human being, and that the less intelligent might be able to handle their emotions better by not over thinking them. While returning home that evening, he gets caught in the rain and comes down with a fever, prompting his mother to nurse him back to health.
094. “The Good Guy Fluctuation”
Leonard meets an attractive female comic book enthusiast named Alice at the comic book store and immediately gets attracted to her. However he is still in a committed relationship with Priya and as a result is torn between cheating on her with Alice or staying loyal to her. He goes to Penny for advice, but he does not find her advice useful, so he goes to Sheldon, who quotes Friedrich Nietzsche's views on morality (Morality is just a fiction used by the herd of inferior human beings to hold back the few superior men). Leonard surprisingly takes Sheldon's advice and goes to Alice's apartment. But just when they are about to have sex, Leonard's conscience gets the better of him. He tells Alice that he already has a girlfriend, prompting her to throw him out of her apartment. Later he tells Priya via Skype about how he tried to cheat on her. To his surprise, Priya accepts his actions, but then reveals that she cheated on him by sleeping with her ex-boyfriend. Leonard becomes very upset at this and closes his laptop on Priya, indicating their breakup.
Meanwhile, Sheldon becomes the victim of a successful Halloween prank by the guys and decides to take revenge by pranking them back. But due to his lack of guile, none of his pranks are successful; Leonard reverses his airbag prank on him; Raj does not get scared of the snake which Sheldon hid in his drawer in their office; Howard and Bernadette pretend that Howard had suffered a heart attack after Sheldon gives him an electric handshake, which actually scares him more. However he manages to finally scare Leonard by leaping out from under the couch cushions in zombie face paint after Leonard speaks with Priya.
095. “The Isolation Permutation”
Amy becomes extremely upset when Penny and Bernadette go shopping for bridesmaid dresses without her and cuts all contact with everyone, including Sheldon. A worried Sheldon goes over to her apartment, where he ends up cuddling her after rejecting her suggestion to have sex. This step further into their relationship makes him uncomfortable, so the following morning, he demands Leonard and Howard to force Penny and Bernadette to apologize to Amy, as he is not her 'snuggle bunny'. When they confront Penny and Bernadette over Amy, they reveal that they did not take Amy because she was very over-enthusiastic about being a bridesmaid and would have been a hindrance to their dress shopping, but feel guilty when they find out that she became really upset over the snub. They go to her neurobiology laboratory to apologize, but she brushes off their apologies, telling that she is used to being shunned by people whom she considers as friends. Later that evening, Amy calls Sheldon and tells him that she is drunk in a liquor store parking lot, prompting him and Leonard to immediately rush there and take her home. The next morning, Penny and Bernadette again try to apologize to Amy. After a few unsuccessful attempts, Bernadette decides to end their standoff once and for all by asking Amy to be her maid of honor at her wedding. She immediately becomes excited at this and forgives them. The episode ends with Amy filming a dress shopping trip with Penny and Bernadette.
096. “The Ornithophobia Diffusion”
Leonard and Penny decide to go to the movies as friends. However Leonard refuses to exhibit the familiar deference to her that he formerly displayed to her as her boyfriend to make her amenable to sex, insisting that they see a documentary on dams instead of a Jennifer Aniston movie and making her pay for her ticket and food. Irritated by Leonard's behavior, Penny begins to flirt with Kevin, a geeky screenwriter. Leonard retaliates by flirting with a woman named Laura. Penny then sabotages Leonard's meeting with Laura, leading to a fight between Leonard and Penny before they decide to return home. Outside the apartment, they apologise to each other and Penny tells Leonard that she actually liked his new-found confidence, but he misses the opportunity to get back together with her by defaulting to his usual deference.
Meanwhile, Sheldon, who suffers from ornithophobia, is afraid and upset when he sees that a large Black-throated magpie-jay (incorrectly identified as a blue jay) has made a nest in his apartment windowsill. He tries all means to get rid of the bird, including mimicking a cat's meow and making Howard design an ultrasonic machine to scare away the bird, all of which fail. Eventually he decides to shoo the bird away using a broom, but when he opens the window, the bird enters the apartment and lands on his spot on the couch. A terrified Sheldon then asks Amy and Bernadette to get rid of the bird, but instead they help him overcome his fear by encouraging him to touch the bird. Sheldon soon grows fond of it, calling it "Lovey-Dovey" and decides to keep it as a pet. However, when Sheldon opens the window to shift the bird's nest to his apartment, the bird flies away, to his dismay. The episode ends with Sheldon revealing to Leonard that he found an egg in the nest and expressing his intention to become "a mommy" by incubating the egg.
097. “The Flaming Spittoon Acquisition”
When Amy visits the comic book store with the guys, she meets Stuart, who takes an immediate liking to her and asks her out, which she accepts. When Sheldon hears about this, he becomes jealous, though he denies it as usual. To make Amy jealous, he asks Penny out, who refuses and instead tells him to reveal his feelings to Amy. Later he interrupts Amy's date with Stuart and finally admits his feelings for her. He then proposes a 31-page Relationship Agreement, which Amy finds romantic and accepts, though she regrets it later when she finds out that she has to take care of her boyfriend's injuries as per Section 4 of the agreement.
Meanwhile, Leonard, Howard and Raj discover that a new expansion pack for Mystic Warlords of Ka'a called Wild West and Witches has come out. Leonard tries to return his expansion pack but Stuart's assistant Dale (who is filling in for Stuart) refuses to take it back. Later Raj buys the Deluxe Limited Edition of the same pack in a collector's tin which annoys Leonard, but he too ends up buying it anyway.
098. “The Speckerman Recurrence”
Leonard receives a Facebook message from a high school bully Jimmy Speckerman which says that he is in Pasadena and wants to have a drink with him. When Leonard meets Speckerman at a bar, the latter reveals that he needs Leonard's help for implementing his potentially money-making idea- a pair of glasses that can convert any movie into 3D- to which Leonard replies that it is impossible to make such a pair of glasses. Sheldon then stands up for Leonard and tells Speckerman that he should apologize to Leonard for all the heinous acts he committed against him while in high school. Later that night, Speckerman comes over to Leonard and Sheldon's apartment drunk and apologizes to Leonard for all the atrocities he committed on him. Leonard forgives him and then lets him stay for the night as he is too drunk to drive, despite Sheldon's opposition. The next morning however, Speckerman once again bullies Leonard, forcing Leonard to finally stand up to his high school bully. This fails; Leonard and Sheldon end up being chased by Speckerman down the stairs instead.
Meanwhile, the girls discuss Leonard meeting his high school bully and their own encounters with bullies. Penny tells that she had played a prank on a smart girl in high school by tying her up and leaving her in a cornfield, revealing that she was actually a bully in her teens. She feels bad for her behavior at school and tries to make amends by calling the people she had bullied to apologize, but they refuse to forgive her. Amy and Bernadette then tell her that she could make up for her past behavior by doing charity. Penny decides to give away her old clothes that she no longer wants, but when the girls go to the clothing bin, they instead steal other old clothes already in the bin. The next night, they return to the bin to steal more clothes, but then Penny realizes that what they are doing is wrong and puts back the clothes they had collected in the bin. However, Bernadette decides to take some boots Amy showed her earlier, and runs away saying "It's okay, I serve soup to poor people!"
099. “The Shiny Trinket Maneuver”
Amy and Sheldon's relationship hits a snag when Sheldon refuses to appreciate the news that Amy's paper is being published in the reputed scientific journal Neuron, causing her to leave their date midway in a huff. When Penny confronts Sheldon over his behavior to his girlfriend, he replies that he is not interested in biology. Later when he discusses the issue with Leonard, Leonard tells him to buy something for Amy to make up for his behavior. He then goes with Penny to the jewelry store. Amy feels insulted initially when Penny tells her that Sheldon bought her jewelry, thinking that he is trying to buy her forgiveness, but changes her mind when she sees it is a tiara. She becomes ecstatic and kisses and hugs him, leaving him confused.
Meanwhile, Howard and Bernadette's relationship also hits a snag when Bernadette reveals to Howard that she hates children and does not want to have them after they get married. This upsets Howard, who wants children of his own, and whose mother continuously nags him to give her grandchildren. He begins to reconsider his relationship with Bernadette and mulls calling off the wedding. Later Bernadette comes over to his house and tells him that they can have children of their own after they get married in respect for his feelings. However she adds that he should stay at home and take care of them while she works, to which he reluctantly agrees. Howard then suggests they use a condom before they have sex.
100. “The Recombination Hypothesis”
When Leonard and Sheldon arrive home Leonard sees Penny through her open door and asks her out, who after initial hesitation, accepts. Their date progresses smoothly until he asks her whether they will get back together. They get into a big argument, following which Leonard returns home in a huff. Later that night, Penny calls Leonard and asks him to come out of his apartment. As he does this, Penny kisses him full on the mouth and they end up having sex in her apartment. After this, they decide to pursue their relationship once again, but also decide to take things slow and pretend they are still single. Leonard finds it difficult to keep the relationship secret; when he returns to his apartment at 3 am, he is forced to lie to Sheldon (who saw him entering the apartment); the next night at the Cheesecake factory, he overplays his fake annoyance over Penny, following which the duo again engage in a heated argument. But later that night, they again have sex. After this, he asks her what they are doing, since every scenario that he plays out about them ends badly, to which she responds that it is because he over-thinks things.
It is then revealed that Leonard daydreamed the entire episode. He is still outside his apartment with Sheldon. Realizing he does over-think things, he goes over to Penny's apartment and asks her out. After initial hesitation, she accepts. The episode ends with Penny preparing for her date. She imagines a scene where she marries Leonard, but is heavily pregnant, prompting her to decide to go to the drug store before the date.
101. “The Beta Test Initiation”
Leonard and Penny have started dating again. With Penny wanting to take things slow and Leonard determined to ensure that their relationship works out this time, they agree to an alpha test relationship - instead of them arguing with each other, they highlight each other's faults and work on them. However this goes poorly as Leonard gives Penny a huge list of her faults, while Penny retaliates by giving Leonard a huge list of his faults. When he tries to patch things up by taking her target shooting, he accidentally shoots himself in the shoe, barely missing his toe. Later Penny assures him that their relationship is progressing smoothly.
Meanwhile, Raj buys a new iPhone 4S and falls in love with its Siri as it is a female voice he can speak to without being drunk. He starts making decisions only after consulting Siri and even defends it after Kripke criticizes it for giving erroneous answers on his iPhone 4S (due to his rhotacism). Later Raj has a nightmare in which he finally meets Siri, who is a beautiful woman, but cannot talk to her due to his selective mutism.
Elsewhere, Sheldon and Amy start a podcast about flags titled "Fun With Flags". Amy provides some suggestions during the podcast, which Sheldon unexpectedly accepts, indicating a deep bond between the two.
102. “The Friendship Contraction”
Sheldon keeps Leonard awake all night with a quarterly disaster preparedness drill. The next day, a tired Leonard refuses to take Sheldon to the dentist as he wants to sleep. Leonard then invokes Section 209 in the Roommate Agreement, which reduces his friendship with Sheldon to an acquaintance, freeing him from his obligations to Sheldon. It soon turns out that Sheldon is stranded without Leonard, as none of his other friends are willing to help him. One night, when the power goes off, Sheldon tries to win back Leonard by showing him an extensive emergency kit, but the latter prefers to go over to Penny's apartment for wine. Sheldon comes over and offers Leonard s'mores and water (distilled from urine) if he accepts him as a friend again. Leonard refuses, but Penny feels sorry for Sheldon and advises Leonard to reconcile with him. Leonard then tells Sheldon that he would accept him as a friend again if he appreciates what he does for him once in a while. Sheldon provides a counter-proposal, offering to celebrate "Leonard's Day" once a year, where Leonard's achievements would be acknowledged. Leonard agrees and reconciles with Sheldon, who then indirectly reveals that he is responsible for cutting the power to the entire apartment so that he could win back Leonard's friendship.
Meanwhile, Howard is anxious as to what nickname the other astronauts in his space mission are going to give him. Raj attempts to get them to choose the nickname "Rocket Man" (an Elton John song) by having Howard change his ringtone to that song and then calling him during a conference call with Mike Massimino. This backfires as during the call, Howard's mother yells that his Froot Loops are getting soggy, and he ends up with "Froot Loops" as his new moniker.
103. “The Vacation Solution”
After being forced to take a vacation by President Siebert, Sheldon decides to spend it working with Amy in her neurobiology lab. However he refuses to do even basic work for Amy properly, such as cleaning beakers or counting bacterial spores, and instead forces her to allow him to do brain dissection. When Amy eventually allows Sheldon to perform brain dissection, he cuts his thumb accidentally and faints after seeing it bleed.
Meanwhile, Bernadette's father wants Howard to sign a prenuptial agreement. Howard, unwilling to sign any prenup, is upset that Bernadette did not tell him directly about the prenup.
Later Penny confronts both Sheldon and Howard at the Cheesecake Factory bar for their behavior towards their girlfriends. The next day, Sheldon goes over to Amy's lab again to apologize for his behavior the previous day. She then invites him to work with her again, but gives him the same basic work of cleaning beakers. Meanwhile, Bernadette tells Howard that her father is insistent on him signing the prenup, at which Howard says that he would talk it out with her father. But when Bernadette reveals that her father is a far right ideologue who hates Jews, Howard decides to put off the talk until he is in the space.
104. “The Rothman Disintegration”
The deranged Professor Rothman is forced to retire, leaving his office vacant. Both Sheldon and Kripke fight for the office and bring it to the attention of President Siebert, who is not interested in listening to their argument. Sheldon and Kripke decide to settle their argument once and for all by playing a game of basketball, as both are bad at sports. However it soon becomes evident that both do not know how to play it, and the challenge is reduced to who bounces the ball highest. Sheldon wins the challenge and gets the office. He enjoys his new office until he finds out that the thermostat for the air conditioner is in another room where its occupant is experiencing hot flashes, the upstairs geology department is too noisy and the mockingbirds are "completely out-of-tune" with the wind chimes.
Meanwhile, Amy gifts Penny an enormous painting depicting the two of them, which Penny absolutely hates. When Bernadette sees the painting, she comments that Penny looks like a man in it, prompting Penny to remove it from her wall and deciding to hang it only when Amy comes to her apartment. Unfortunately, Amy finds out that Penny removed the painting and becomes upset, thinking that her friendship with Penny is one-sided. Penny consoles Amy by lying that she removed the painting from the wall because Bernadette was jealous that she was not in the painting. Later Penny hangs the painting on the fourth wall.
105. “The Werewolf Transformation”
Sheldon's regular barber Mr. D'Onofrio has been hospitalized in a coma and he refuses to get his hair cut from his nephew Angelo. Penny offers to cut Sheldon's hair as she used to cut her brother's hair, but he refuses. A week later, Sheldon has still not got his haircut and on Penny's advice, decides to relax his regimented lifestyle and "embrace the chaos". He begins to do things he never used to do before, like wearing his Tuesday pajamas on Thursday night and playing bongos at 3 am. This wakes Leonard and Penny, who plead with Sheldon to stop playing the bongos, to no avail, and he leaves the apartment still playing them. The next morning, they find him asleep on Amy’s couch. With Amy's vote of confidence, Sheldon agrees to let Penny cut his hair. Sheldon is impressed with the way Penny had cut his hair, but when she is trimming his neck, she shaves off the back of his head accidentally.
Meanwhile, Howard goes for astronaut training in Houston to prepare for his space mission. He confides to Bernadette via webcam his experiences in training, which involved vomiting during Zero-G training and having a horrible survival test. Bernadette feels pity for Howard and rushes to Houston, where she quickly finds out that his mother is already there to take care of him.
106. “The Weekend Vortex”
Raj suggests that he and the guys spend the entire weekend together engaging in a gaming marathon in which they would play the new Star Wars online game. However Sheldon already promised Amy that he would attend her Aunt Flora's 93rd birthday party and meet her family during the weekend and reluctantly decides not to take part in the marathon, but still tries to convince Penny to make Amy change her mind, to no avail. Sheldon eventually decides to go with Amy, but also brings his laptop so that he can play with the guys remotely. Amy gets peeved at Sheldon and tells him to return to his apartment if playing with the guys is more important than honoring his commitment to her, which he does. Later Raj gets furious at Howard when he brings Bernadette to the marathon after being forced to include her. Meanwhile, Amy, having returned from her aunt's birthday party, confides her feelings about Sheldon to Penny, who then tells her to create a scene at her boyfriend's apartment. She does this, with Penny too admonishing Sheldon for being a bad boyfriend. At this, Raj goes ballistic and yells about how different the group was before Leonard, Howard and Sheldon got girlfriends, how he is the only one in their group who does not have a girlfriend and adds that even if he gets a girlfriend, he has to face the shame of being the guy who got a girlfriend after Sheldon. The girls immediately leave the apartment and the guys get back to their marathon. The next morning, the marathon ends when Howard’s mother bangs on the apartment door demanding an explanation for Howard's weekend-long absence and forcing him to return home.
107. “The Transporter Malfunction”
After Sheldon complains about Penny's constant mooching of their food, she buys him and Leonard each a mint-conditioned vintage Star Trek transporter from 1975. She is disappointed when both refuse to take them out of their boxes since they want to preserve the toy's value. That night, Sheldon has a dream where his Spock action figure tells him to open his transporter and play with it. When Sheldon does this, he breaks his transporter accidentally. He then changes his broken toy for Leonard’s toy, figuring that he will never find out since he does not plan to open his. Later Sheldon has a nightmare where his Spock action figure chastises him for switching the two transporters. When Leonard decides to play with his toy since it is a gift from his girlfriend, Sheldon admits to breaking his toy and switching it with Leonard's.
Meanwhile, faced with the prospect of attending Howard's wedding alone, Raj tells his parents to find a suitable girl for him. He meets the prospective bride Lakshmi in a restaurant and both hit it off immediately. It soon turns out that Lakshmi is a lesbian and accepted to meet Raj as it is difficult to come out in Indian culture, but nevertheless decides to marry him as she thinks he is gay. Raj too contemplates marrying her, despite the fact that he is never going to have sex with her, and rebuffs Howard's advice to find some other girl. Finally, Howard and Bernadette gift Raj a Yorkie puppy to cheer him up and make him forget about Lakshmi.
108. “The Hawking Excitation”
Howard is hired to maintain Stephen Hawking's motorized wheelchair while he is guest-lecturing at Caltech. He plans to introduce Sheldon to Hawking (Sheldon considers Hawking his idol) until Sheldon insults him yet again about his lack of a doctorate. Sheldon pleads with Howard to introduce him to Hawking, to no avail. He then asks him to give his paper on the Higgs boson to Hawking, to which he agrees, but only if he does several tasks for him. Howard then asks him to give him a compliment about his job. Sheldon replies that he never said that Howard is bad at his job, he just feels that his job is not worth doing. Howard accepts his backhanded compliment and reveals that he had already given Hawking his paper three days ago and that he wants to meet him. Hawking is very impressed with Sheldon's paper, but then mentions that he had made an arithmetic mistake as a result of which the entire paper is wrong. At this, a shocked Sheldon faints.
109. “The Stag Convergence”
The guys are planning Howard's bachelor party. Howard tells them that no strippers should be hired for the party, as he had promised Bernadette. Stuart, Kripke and Wil Wheaton are also invited. At the party, everyone offers a toast. A drunk Raj talks about his friendship with Howard revealing various and sundry things about Howard. Wheaton records Raj's entire speech and uploads it onto YouTube. When Bernadette, who doesn't know anything about Howard's perverted and womanizing past, sees the video, she becomes extremely upset and becomes unsure about marrying a man that she doesn't seem to know. She even becomes upset at Penny because she was the one who introduced her to Howard, despite knowing about Howard's past. She confines herself to her bedroom, not returning Howard's calls. Howard gives Penny a message to pass on to Bernadette saying that he is sorry, that he is as disgusted by his past as she is and credits her for reforming him, which reduces Penny to tears, moved by the genuineness of his apology. When Bernadette hears this, she immediately forgives him, though she is still mad at him, and adds that the wedding will still take place. The episode ends with Leonard wanting to have sex with Penny in the laundry room, which she refuses.
110. “The Launch Acceleration”
Howard receives a call from NASA saying that his mission to the International Space Station has been cancelled due to problems with the Soyuz capsule during a pressurization test. He is ecstatic as he is actually terrified of going to space and looks forward to his wedding. However he later receives another call from NASA saying that he will be sent to space after all as they want his telescope on the International Space Station, though his launch date will be pushed up to the Friday before his wedding. He decides to talk to Bernadette's father to postpone the wedding. To his surprise, Mike strongly approves of him going to space and reveals that he did not think that he was suitable for Bernadette until he heard about the space mission.
Meanwhile, Leonard and Penny decide to take their "beta test" relationship to the next level by having sex. However Leonard proposes to Penny during sex as a result of which Penny becomes extremely upset. After unsuccessfully trying to pacify her, he leaves her apartment. Later when the couple meet each other in the apartment stairwell, Penny says no to Leonard's wedding proposal, though they will still date.
Elsewhere, Amy tries to use transference to increase Sheldon's feelings for her by making him happy using his love for various other topics (his mother's cooking, video games etc.). Amy's actions seem to work on Sheldon who is not happy about it but makes no attempt to stop her.
111. “The Countdown Reflection”
Howard and his two fellow astronauts Dimitri Rezinov and Mike Massimino are in the Soyuz capsule, awaiting lift-off to the International Space Station from Kazakhstan. Nervous and not looking forward to the launch, Howard begins to reflect on the last couple of days, revealing that he married Bernadette before he left.
When Bernadette receives a necklace from Howard with a star pendant on it which he plans to take with him to space, she tells him that they need to get married before he goes to space. They decide to get married in City Hall that very afternoon with only their friends as guests. Amy is devastated that her position as Maid of Honor has been reduced to nothing, but is allowed to wear the dress she bought to City Hall. Unfortunately, they do not get married that day as there are too many other couples in front of them. Raj then suggests that they get married on the roof of Leonard, Sheldon and Penny's apartment building on Sunday morning, which will coincide with the Google satellite taking new photographs of Pasadena, with himself, Leonard, Sheldon, Penny and Amy as ministers. The wedding takes place successfully. While Howard and Bernadette exchange their vows, the camera pulls back from the apartment roof - showing a glimpse of Mrs. Wolowitz - and then pulls back further to a view of the planet Earth.
The episode ends with Howard being launched into space. Everyone nervously watches the space launch from Leonard and Sheldon's apartment. Bernadette takes Raj’s hand, Penny takes Leonard’s hand, and a very surprised Amy has her hand taken by Sheldon who wishes Howard well with the words "Boldly go, Howard Wolowitz".
The Complete Season Six
112. “The Date Night Variable”
At the International Space Station, Howard receives a call from his mother, who is furious at him on finding out that he is planning to move out and live with Bernadette after he returns from space. Not wanting to disappoint his mother, who wants him to stay, and Bernadette, who wants him to move out, he lies to both of them.
Meanwhile, Raj, who is feeling lonely now that Howard is in space, is invited by Sheldon to his second anniversary date with Amy on the pretext of "outsourcing" any romantic activities he must perform with Amy as stipulated in the Relationship Agreement to an Indian. Amy is not happy with Raj's presence and forces him to leave. After this, he goes over to Leonard and Sheldon's apartment, where Leonard and Penny are spending the evening together to talk about the status of their relationship. Leonard is unhappy with Raj's intrusion, but is forced to accommodate him because of Penny, who is unwilling to talk about their relationship. When a drunk Raj starts forcing Penny to declare her love for Leonard, he is thrown out of the apartment. He then goes over to the comic book store, where he and Stuart bond over a nightcap following which they decide to hang out together the following night.
Elsewhere, Sheldon and Amy's date is not going too well. Sheldon is unable to comprehend Amy's flirtatious gestures, prompting the latter to walk out of their date in disgust. When he demands that she come back because he needs her to drive him home, she returns and tells him to say something romantic to her from his heart, failing which she will break up with him. Sheldon then offers a stunningly romantic soliloquy, which she finds incredibly touching until she finds out that it is a quote from the first Spiderman movie.
113. “The Decoupling Fluctuation”
While sorting out Bernadette's wedding gifts, Penny confesses that she is unsure of her feelings towards Leonard and where their relationship is going, and is worried she might break up with him again. She asks Bernadette and Amy not to mention this to Leonard; however, Amy tells it to Sheldon. He is unable to keep the secret, but restrains himself from spilling the beans to Leonard. Later that night, he enters Penny's apartment, wakes her up and tells her not to break up with Leonard regardless of her feelings towards him. The next day, Penny decides to talk to Leonard about her fears and doubts, but just as she is about to do so, she looks at Leonard's sad face and ends up sleeping with him instead. Later, she insists she's fine with where they are going, as they aren't getting married.
Meanwhile, Stuart joins the gang, subject to Sheldon's condition that he acts like Howard, who he is replacing as Raj's friend. This includes having Raisinets while watching a movie and playing the same cards Howard plays during Mystic Warlords of Ka'a. Later he and Raj go to a bar meet some women, which is reminiscent of the old Howard and Raj friendship.
Elsewhere, at the space station, Howard is being bullied by his co-astronauts Mike Massimino and Dimitri Rezinov. When Bernadette finds out, she tells him to stand up to them. He does so, but ends up having a mouse face along with his nickname Froot Loops drawn on his face by the duo.
114. “The Higgs Boson Observation”
Sheldon receives his childhood scientific journals from back home in the hope of getting a Nobel Prize for any extraordinary research he may have done in his childhood. He feels too important to read the journals himself, so he hires an attractive female grad student Alex Jensen to do the work. She surprisingly tolerates Sheldon and his eccentricities, having been brought up in a family of scientists. When Amy finds out about Alex, she becomes jealous and investigates Sheldon's office, despite Penny's assurances that Alex is not interested in Sheldon. Later, in the Caltech cafeteria, Amy and Penny notice Alex and Leonard talking with each other, with Alex actually flirting with him making Penny jealous. Amy then points out that even though Penny has said she is still unsure of her feelings for Leonard, subconsciously the thought of him with another woman definitely bothers her, and Penny slowly realizes that Amy may be right. That night, Alex comes over to Leonard and Sheldon's apartment after finding out that one of Sheldon's elementary school projects actually qualifies for a Nobel Prize and flirts with Leonard again, prompting Penny to immediately take him to her apartment for sex.
Meanwhile, Howard is homesick and wants to return to the Earth as soon as possible. When the Soyuz capsule to take him and his co-astronauts home is delayed, he finally cracks and starts suffering anxiety attacks and blabbering nonsense. Eventually, the other astronauts give him a sedative which makes him relax, but also causes him to act strangely, such as taking off his pants and windmilling in the space station.
115. “The Re-Entry Minimization”
After losing badly to Penny and Amy in Pictionary, Sheldon and Leonard challenge them to a series of games after Penny declares that she can beat them at anything.
Meanwhile, Howard returns to the Earth and is expecting a grand welcome from the public and his friends. Only Bernadette receives him at the airport, with the grand welcome from the public reserved for Howie Mandel. The couple then go to Bernadette's apartment to enjoy their "honeymoon", which is cut short as Bernadette, who is having the common cold, falls asleep immediately after taking Benadryl. Howard leaves for his home, where he is shocked to find out that his mother is having an affair with his dentist. He then goes to Raj's apartment, where he finds out that Stuart, who is now staying with Raj, has replaced him as Raj's best friend; they had even planned to go to a Sound of Music sing-along. He immediately leaves for Leonard and Sheldon's apartment, but leaves as soon as he arrives after Leonard, Sheldon, Penny and Amy, who are still engaged in their contest, shoo him away. Finally he ends up in a diner, where he realizes that he has caught Bernadette's cold.
116. “The Holographic Excitation”
Stuart decides to organize a Halloween costume party at the comic book store, with Raj being the party manager. While Amy and Bernadette decide to go with Sheldon and Howard respectively, Penny is not interested as she does not like going to parties at the comic book store. Amy and Bernadette then convince her to show interest in Leonard's activities just as how Leonard shows interest in her activities even though he actually does not like them. Listening to their advice, she visits Leonard's lab the next day, where she is really fascinated by his work, as a result of which she gets turned on and ends up having sex with him in the lab. This repeats every time she visits Leonard's lab or whenever Leonard shows how smart he is. At the party too, they end up having sex in a similar fashion.
Meanwhile, Sheldon and Amy argue over what couple they should go as to the party. While Amy suggests Romeo and Juliet or Raggedy Ann and Andy, Sheldon prefers R2-D2 and C-3PO, Hewlett and Packard or salt and pepper. Eventually both agree to a compromise- Amy dresses up as Raggedy Ann, while Sheldon dresses up as Raggedy C-3PO.
Elsewhere, Howard cannot stop talking about his space mission, which bores his friends and even Bernadette. Before having sex, Bernadette tells him that she and the others are tired of listening to his adventures his space and forbids him from talking about it, which does not go down well with him. He refuses to attend the party unless he can talk about his space mission, but is eventually forced to attend by Bernadette. At the party, he lashes out at Raj for forcing him to keep quiet about his space mission, following which Bernadette confronts him, upon which he reveals that without his space adventure, he is "just...Howard Wolowitz". Bernadette then consoles him, saying that she fell in love with "just...Howard Wolowitz", after which they kiss. Later that night, Raj sends Howard a video of astronaut Buzz Aldrin irritating children by constantly referring to his trip to the Moon. On seeing the video, Howard finally realizes how irritating his constant mentioning of his space mission sounded to others.
117. “The Extract Obliteration”
Penny rejoins community college in a bid to clear history so that she can finally graduate. She does not want Leonard to know as he would get very excited about it, but on Bernadette's and Amy's advice, she tells him anyway. Later that night, Leonard reads Penny's homework paper on slavery, which turns out to be really bad, so he rewrites it entirely and shows it to Penny the following morning, but she lashes out at him and refuses to accept the paper, adding that she will do all her college work without anyone's help. Later, Penny shows Leonard that she had got a B- in her paper without taking anyone's help and mocks him for not thinking that she was smart enough. It then turns out that Bernadette and Amy had helped her in rewriting the paper.
Meanwhile, Sheldon starts playing the online game Words with Friends with Stephen Hawking and manages to win almost every game against him. Hawking eventually stops playing, which makes him distraught, thinking that Hawking stopped playing with him because he was beating him continuously. The next day, Hawking again starts playing with Sheldon, who in a bid to ensure that Hawking does not stop playing with him again, purposely loses to him. That night, he receives a phone call from Hawking, who mocks him for losing. The episode ends with Hawking asking "What do Sheldon and a black hole have in common?" and leaving Sheldon guessing. Hawking tells him, "they both suck".
118. “The Habitation Configuration”
Sheldon invites Wil Wheaton for a special Fun With Flags podcast about Star Trek flags. Wheaton and Amy do not get along, prompting Amy to request Sheldon to ask Wheaton to leave. When he refuses, she leaves in a huff, creating a standoff between the two. After unsuccessfully trying to make Amy respect Wheaton, he confesses his relationship worries to Penny at the Cheesecake Factory bar, who chides him for not standing up for Amy when Wheaton was insulting her despite being a Texan. In the course of their conversation, he also gets drunk after Penny mischievously offers him Long Island Iced Tea. Still drunk, he then goes over to Wheaton's house and forces him to apologize to Amy, challenging him Texan style. Wheaton, who is surprised by Sheldon's drunk behavior, does apologize, shortly before Sheldon comes to his senses and vomits in his shrubs. Later, Sheldon and Amy, who have now reconciled, reshoot the special podcast with LeVar Burton as the special guest, but Amy does not get along with him either.
Meanwhile, Howard finally moves into Bernadette's apartment after Bernadette reminds him of his promise to her that he would move out of his house once he returns from space. While unpacking his things at Bernadette's apartment, he comes across his old magic set. He then reminisces about how he used to cheer up his mother by performing magic tricks after his father left them. On hearing this, Bernadette changes her mind and forces him to move back in with his mother, at least until he does not have mother issues.
119. “The 43 Peculiarity”
Leonard becomes jealous of Penny's classmate, a British student named Cole, who is working with Penny on an oral class project, thinking that he is probably hitting on her. When he encounters Cole in the apartment lobby, he indirectly threatens him to stay away from Penny, oblivious to the fact that Cole is not interested in Penny. Unfortunately for him, Penny notices this and becomes infuriated at him, upset at the fact that he is not trusting her. The next day at the Caltech cafeteria, Leonard talks about his problem with Alex, who starts flirting with him in reply, though he is unaware that she is hitting on him. That night, he meets Penny in the lobby and after revealing to her that he is really insecure about other men hitting on her, she confesses her love for him, which shocks both of them as it is the first time ever that Penny confessed her true feelings for Leonard. They awkwardly decide to pretend it's not a big deal.
Meanwhile, Howard and Raj wonder where Sheldon disappears between 2:45 pm to 3:05 pm every day. They follow him down to Caltech's basement and notice him entering a storage room. They return to the basement at midnight and break into the room, only to find a chalkboard with the number "43" written on it. After breaking their heads over-thinking what the "43" actually means, Howard installs a camera which he stole from the Mars Rover so that they can spy on what Sheldon does in the room. Unfortunately, Sheldon finds out that Howard and Raj are spying on him using the camera and creates a phony video of himself being attacked by an alien creature in the room after creating a small wormhole to find life in the 44th parallel universe (with the previous "43" universes having no life). He then confronts the duo, admonishes them for spying on him and reveals that he goes into the room to relax his mind from the difficulties he has to face in his daily life, but refuses to tell them what the "43" means. It is then revealed to the audience that Sheldon plays with a hacky sack in the room, with the "43" on the chalkboard being the maximum number of consecutive hacky sack hits that he has achieved.
120. “The Parking Spot Escalation”
Using the money he earned from the space mission, Howard buys a new car. He is also assigned Sheldon's parking space, as Sheldon has never used it. This does not go well with Sheldon, who wants his parking space back even though he does not own a car and does not know how to drive, and begins to engage in a bitter feud with Howard to get back his parking space. Sheldon takes Howard's Iron Man helmet and sits in Howard's car naked, after Howard sits in Sheldon's spot naked. The fight eventually spills over to the girls' side too, with Amy and Bernadette supporting Sheldon and Howard respectively. Amy helps Sheldon deface the parking spot and parks her car there, and Bernadette responds by having it towed and scratching her car. Caught in the middle, Penny accidentally gets her nose broken by Amy when she tries to hit Bernadette. Raj finally ends their feud once and for all by making Sheldon and Howard foster an agreement where Howard keeps the parking space until Sheldon learns to drive or gets a Batmobile. Sheldon and Amy and Howard and Bernadette reconcile at The Cheesecake Factory, where a battered Penny approaches them and retorts "Yeah, everybody's happy. Great!" The episode ends with Sheldon taking his cushion to the dry cleaner's, as it was sat on by a naked Howard during their arguments.
121. “The Fish Guts Displacement”
Howard and Bernadette have dinner with Bernadette's parents. Howard, who doesn't get along with his father-in-law, is unable to start even a small and mundane conversation with him as they have nothing in common. Bernadette requests her father to take Howard fishing so that they can get a chance to know each other and bond together, an idea to which Howard and his father-in-law reluctantly agree. Since Howard does not know how to fish, nor do Leonard and Raj, he seeks Penny's help, as she is the only one in their gang who knows fishing. On the morning of the trip, Howard and his father-in-law both admit that their wives forced them to go fishing together. This admission actually makes them bond, as they finally found something they have in common: they have dominating wives, despite having successful careers. They decide to go to a casino in Palm Springs instead.
Meanwhile, Amy comes down with the flu. Sheldon reluctantly takes care of her, as it is mentioned in their Relationship Agreement that either partner has to take care of the other when he/she is sick. Amy enjoys being taken care of by Sheldon as it is the only time he shows his caring and loving side. Eventually she recovers, but she feigns her sickness so that he can continue to take care of her. The lie is exposed when Sheldon, who was concerned with Amy not recovering from her "illness" despite his best efforts, gets her cheek swab cultured in a lab, only to find out that she has recovered.
122. “The Santa Simulation”
The guys and Stuart decide to play Dungeons and Dragons on Saturday night and forbid the women from participating. Leonard, who is the dungeon master, sets up a Christmas theme for the game where Santa Claus must be rescued from a gang of ogres, much to Sheldon's chagrin, who doesn't like Christmas. As the game progresses, Raj's character is killed, prompting him to leave the game and join Penny, Bernadette and Amy on a girls' night out. They head to a bar, where the girls decide to find a woman for Raj. After being rejected by a woman who just broke up with her boyfriend, Raj laments about how he is unable to get a girlfriend despite being successful. The girls sympathize with him, with Amy even sharing her experiences of loneliness with him. This makes him happier, though it also makes him attracted to Amy, the only woman in their gang he was not attracted to so far.
Meanwhile, back at Leonard and Sheldon's apartment, the guys' game continues. When they reach the dungeon where Santa is imprisoned, Sheldon paralyzes Howard's and Stuart's characters and yells at Santa for not bringing back Pop-Pop (Sheldon's late maternal grandfather, the only member of Sheldon's family who encouraged his scientific pursuits) from the dead, which is what he'd asked for when he was a child. He refuses to help Santa, who is then eaten alive by the ogres. Later, Sheldon has a nightmare in which he finds Santa in the living room; Santa says he is sorry for being unable to bring someone back to life, and says he has a present for Sheldon; anticipating a train, Sheldon is horrified to see Santa firing a cannon at him, and wakes in a panic.
123. “The Egg Salad Equivalency”
Alex is planning to attend Kip Thorne's lecture about quantum foam on Saturday and invites Leonard to accompany her. Though he declines as he has a date with Penny the same day, Alex offers to talk about the lecture "over dinner". Leonard realizes that Alex is hitting on him, and he is stunned over being the object of attention from two beautiful women (more stunned that it's two at the same time), which flatters him, though he is still committed to his relationship with Penny. When Sheldon finds out, he gets frustrated at Alex as he feels that she needs to solely dedicate her time to him since she is his assistant. On Bernadette's advice, Sheldon talks to Alex the next day about the issue. He inadvertently uses sexually inappropriate language while talking to her, prompting her to file a sexual harassment complaint against him with the HR Department. At the HR Administrator's office, Sheldon insults the female HR admin by inadvertently blurting out racist (the HR admin is African American) and misogynist comments, which makes her furious, but then he lodges complaints on Leonard, Howard and Raj for some earlier misdemeanours in an attempt to draw the admin's anger away from him. Meanwhile, Leonard plays his cello to apologize to Penny, and tries to convince her that he doesn't have feelings for Alex, but she still feels insecure. He assures Penny that she is the only one for him, just before he, Howard and Raj are called to the HR admin's office as well. The admin eventually instructs Sheldon to take an online seminar on sexual harassment; Sheldon forces Alex to complete it, not wanting to waste time on such "nonsense". Later, Penny tells Leonard that she has found a way to deal with her insecurities: she dons a pair of thick-rimmed glasses to look like a scientist, which turns Leonard on like crazy.
124. “The Bakersfield Expedition”
The guys decide to go to the Bakersfield Comic-Con. On the way, they make an unscheduled stop at Vasquez Rocks, where the original Star Trek: The Original Series was filmed. There they dress up as Star Trek: The Next Generation characters, but whilst they are taking pictures of themselves someone steals Leonard's car. Stranded in the middle of the Californian desert, unable to change back into their regular clothes and with no other means of transportation or communication (the guys' clothes and phones were in the car), the four try to hitch a ride to Bakersfield, but no one stops for them. They then walk to a nearby diner, where they lodge a complaint about Leonard's stolen car with a police officer. Demoralized, the four skip Comic-Con and return to Pasadena in a rental car arranged by Howard's mother.
Meanwhile, the girls wonder how the men are into comics and superheroes, stuff which they believe are only for kids. To find out, they go to the comic book store and buy some comic books. When they return to Penny's apartment, they read them and then find themselves drawn into a heated argument about Thor's hammer Mjolnir. They even enter Leonard and Sheldon's apartment and read their comics to prove their points about Thor and his hammer.
125. “The Cooper-Kripke Inversion”
Howard and Raj order customized action figures of themselves. The figures they actually receive do not look like them. They then buy a 3D printer for $5000, which they use to make precise figures of themselves and Bernadette. When Bernadette sees the figures of Howard and herself, she is very happy until she finds out how much Howard paid for the printer. She removes Howard from their joint account until he realizes the value of money. The next day, he sells his half of the printer to Raj.
Meanwhile, Sheldon and Kripke are forced to work together on a fusion reactor project. To Sheldon's dismay, Kripke's work turns out to be far superior and more advanced than his. This makes him so upset that he even allows Amy to hug him. The next day, Kripke confronts him over the poor quality of his research, but thinks that it is because he now has a girlfriend with whom he has constant sex. Surprisingly, Sheldon does not object to Kripke's incorrect theory and goes along with that story so that Kripke and his other colleagues never realize that he is not the smartest person in Caltech. In conversation with Penny that evening, he tells something completely unbelievable which shocks Penny: he reveals that it is a "possibility" that he could one day have a physical relationship with Amy.
126. “The Spoiler Alert Segmentation”
After Sheldon gives away the ending of Harry Potter and the Half Blood Prince which Leonard is reading, Leonard gets into a heated argument with him, following which he decides to leave their apartment and move in with Penny. Penny is uncomfortable with her boyfriend moving in with her, though she is unable to convince him to move back with Sheldon. Meanwhile, Amy decides to move in with Sheldon after finding out that Leonard moved out, which Sheldon finds uncomfortable. Later, Sheldon and Penny comfort each other over their similar predicaments and decide to tell the truths to their respective partners. When Sheldon tells Amy to move out, she gets incensed at him. He gets scared and tells her that the reason he does not want her to live with him is that Leonard may come back since Penny does not want to live with him. This causes a brief spat among the quartet. Amy eventually gets so angry at Sheldon and Leonard that she decides to move in with Penny, a suggestion which makes Penny uncomfortable again. A dejected Leonard then moves back in with Sheldon, but not before Sheldon gives away the plot of a The Walking Dead episode.
Meanwhile, Howard asks Raj to visit his mother, who is depressed ever since she broke up with her dentist boyfriend, while he is away on a trip with Bernadette and her colleagues to Las Vegas. At the Wolowitz residence, Raj sees how depressed Mrs. Wolowitz is, prompting him to spend the night there. She begins to pamper him just like she used to pamper Howard and prevents him from leaving, hiding his clothes and car keys. Eventually, he tries to escape from Howard's bedroom window, but is pulled back by Mrs. Wolowitz.
127. “The Tangible Affection Proof”
On Valentine's Day, Leonard and Penny go on a double dinner date with Howard and Bernadette to a fancy restaurant. Howard and Bernadette are in a foul mood and constantly bicker during the date, due to Bernadette taking away Howard's Xbox when he was caught playing Assassin's Creed instead of doing the laundry. Leonard and Penny, on the other hand, are quite happy until Penny sees her ex-boyfriend proposing to his girlfriend. She becomes extremely uncomfortable and starts obsessing about them, which upsets Leonard, causing a fight between the couple. When they return home later that night, Leonard confronts Penny for ruining their Valentine's Day, to which Penny finally reveals her fears; if their relationship continues to be steady, Leonard would propose marriage to her, which she is still not ready for. At this, Leonard suggests that she proposes to him whenever she is ready to get married; he will not propose to her ever again. Penny then asks Leonard to be her valentine, which he accepts.
Meanwhile, Sheldon plans to buy the best Valentine's Day gift for Amy. He entrusts this work to Alex, who buys three for him to choose from: a music box shaped like a harp which plays Amy's favorite songs, a map of England showing the journeys of the characters from The Canterbury Tales and a rare signed print of Santiago Ramon y Cajal's drawings of brain cells. He picks the latter, but decides to keep it for himself. Later that night, Amy comes over and suggests that they celebrate in a manner he would enjoy - no romance or gifts, order a pizza and watch either a Star Trek or a Star Wars movie. Sheldon is impressed with Amy's gesture and in return makes her his emergency contact; initially delighted, she quickly becomes exasperated when she has to keep leaving work to attend to the imaginary illnesses caused by his hypochondria.
Elsewhere, Raj and Stuart, both of who do not have a date for Valentine's Day, throw a party at the comic book store on Valentine's Day for those people who do not have dates for the occasion. During the party, Raj speaks about how single people are not truly alone as long as they have each other, but when a young woman named Lucy starts talking to him and he asks her out for coffee, he derides the single people present at the party, including Stuart, and leaves the comic book store with her.
128. “The Monster Isolation”
Following the previous episode, Raj and Lucy are having coffee. Lucy is clearly uncomfortable being with Raj and soon escapes from their date by pretending to go to the bathroom. This makes Raj extremely upset, as he feels that he is incapable of dating any woman, and shuts himself up in his apartment, refusing to go to work or hang out with his friends. When Howard confronts Lucy over her ditching Raj, she asks him to give Raj a note with her phone number. When Raj sees the note, he initially shows a lack of interest in resuming his relationship with Lucy, though he changes his mind eventually. Later, Lucy comes over to his apartment and apologizes to him for walking out of their date and when asked why, she reveals that she is very shy and uncomfortable around people she does not know, but she is working on it. At this, he becomes pleased and also reveals his selective mutism, which she does not believe, but accepts to go on another date with him to find out.
Meanwhile, Sheldon invites Penny as his special guest for a Fun With Flags podcast about the flag of Nebraska. Later, while chatting with Amy through webcam, Amy advises him to compliment Penny in return as she was helpful enough to star in his podcast. When he does so, she invites him to her class play A Streetcar Named Desire that Friday, which he reluctantly accepts to attend with Amy and Leonard on Amy's advice. The play turns out to be a success, with Penny putting up a strong performance, which impresses even Sheldon.
129. “The Contractual Obligation Implementation”
As part of their contract with Caltech, Leonard, Sheldon and Howard are required to serve on a committee that promotes science among young women. Neither Sheldon or Howard show any interest in this project, but on Leonard's cajoling, Sheldon suggests that they focus on middle school girls and inspire them to pursue science after they finish school. They go to Howard's old middle school to implement their ideas. At the school, they fail to enthuse the girls to show an interest in science. With their attempts to inculcate a love for science among the girls having failed, Sheldon contacts Amy and Bernadette to talk to the girls about pursuing a career in science as they are women scientists.
Meanwhile, the girls skip work and go to Disneyland. There, they head straight to a place where people are made to look like Disney princesses. All of them want to be Cinderella, but Bernadette insists that she be Cinderella since she planned the trip and drove them, forcing Penny to be Aurora from Sleeping Beauty and Amy to be Snow White. Back at their respective apartments, Bernadette's and Penny's costumes turn on Howard and Leonard respectively. On the other hand, Amy, still in her Snow White costume, wants Sheldon to kiss her Snow White-style, but he is not interested.
Elsewhere, Raj arranges a "texting date" with Lucy in the library, where they interact with each other by texting due to their social problems. At then end of their date, Lucy attempts to kiss Raj, but gets shy before doing so and leaves. This impresses Raj, who counts it as foreplay.
130. “The Closet Reconfiguration”
Sheldon is tricked into cleaning Howard and Bernadette's closet while at their dinner party. While doing so, he comes across a letter Howard's long-lost father had written to Howard on his 18th birthday and reads its contents. When Howard finds out about the letter, he destroys it without bothering to read it and starts acting strangely. The rest of the gang, curious about what was written in the letter, force Sheldon to reveal the letter's contents, as he was the only person who had read the letter. Eventually, Howard finds out that Bernadette and his friends knows about the letter's contents and storms out of a dinner party organized by Leonard and Penny. Later that night, Sheldon figures out a way to reveal the contents of the letter to Howard without letting him actually know what was written in it. He asks the rest of the gang to come up with an account of the letter's contents, with only one of the accounts actually being true; Raj, who speaks first, tells that Howard's father had sent Howard a birthday card; Sheldon tells that the letter contained a map to the lost treasure of the famous pirate One-Eyed Willy, which turns out to be the plot for The Goonies; Amy tells that Howard's father secretly turned up at his son's high school graduation and cried because he was proud of him; Penny tells that the letter explained that the reason Howard's father left his family was that his "other life" caught up with him and left his family as a result to keep them safe; Leonard tells that Howard's father wrote about the importance of family and that Howard should never abandon his family like he did; Bernadette tells that the letter contained a photo of Howard's father holding him as a baby with the words "Howard, my son, my greatest gift". Howard is pleased, wishing that all of the accounts were true, and returns to his happy self.
131. “The Tenure Turbulence”
With the death of Professor Tupperman, a vacancy for a tenured position opens up. Sheldon, Leonard, Raj and Kripke fight for the post and try to impress the head of the tenure committee, who happens to be Janine Davis, the HR administrator of Caltech. Both Leonard and Kripke exercise along with her at the gym in an attempt to talk to her, with Leonard eventually suffering an asthma attack; Raj sends her a 90-minute video about himself; Sheldon gifts her a DVD of the TV miniseries Roots to make up for his racist comments about her in The Egg Salad Equivalency but, puzzled when she clearly doesn't appreciate that either, offends her by asking "you are black, right?". Sheldon, Leonard and Raj eventually decide to attend a memorial service for Professor Tupperman as the tenure committee is going to be there, with Sheldon and Leonard deciding to take Amy and Penny respectively with them to boost their reputation with the committee. When they encounter each other at the memorial service, they lash out at each other, with even Amy and Penny joining in support of their respective boyfriends. The fight stops only when Leonard comes to his senses and realizes that he would rather lose the tenured post than lose his friends. The five decide to return home, but when they see Kripke flattering Mrs. Davis, they attend the memorial anyway. Eventually, Sheldon, Leonard and Raj are shortlisted for the tenured position purely based on their accomplishments. Sheldon thanks Mrs. Davis for shortlisting him, but offends her again by giving her what he believes is a "traditional black handshake".
132. “The Closure Alternative”
Sheldon is upset when the SyFy television series Alphas is cancelled on a cliffhanger and unsuccessfully makes calls to the SyFy network to put it back on air. When Amy notices this, she decides to teach him to overcome his "closure" obsession. She leads him through a series of activities, forcefully stopping him from completing the activity just before he is about to finish it. These events make Sheldon furious at Amy, but he hides his true feelings from her and lies to her that he has been cured of his closure obsession. Once Amy leaves, he completes all the activities he was denied from finishing by Amy.
Meanwhile, Leonard, who is concerned that he and Penny do not share any interests, asks Penny to watch Buffy The Vampire Slayer with him, thinking that it could become their common interest. Penny does not enjoy the show, but pretends to like it so that she does not hurt Leonard's feelings. On conversation with Bernadette, Penny reveals that she is not passionate about many things like Leonard, but decides to find an activity she is passionate about. Later, while she is having dinner with Leonard, she finally reveals what she is passionate about: Leonard, as well as his friends, including Sheldon.
Elsewhere, Raj reads Lucy's blog, where Lucy had written about their date. He gets upset when he reads what Lucy had written about him: she had described him as "a little feminine". On conversation with Howard, Howard admits that Raj is effeminate, but asks him to work that out to his advantage with Lucy. Raj refuses to take that advice and tries to behave more manly during a dinner date with Lucy. His "manly" behavior creeps Lucy out. Just as Lucy is about to walk out from their date, Raj reveals what he had seen in her blog. Lucy then admits that he is feminine in a "good way", such as being sweet, thoughtful and having a "skin like caramel".
133. “The Proton Resurgence”
When Sheldon and Leonard find out that Dr. Arthur Jefferies aka Professor Proton, who was famous for hosting a children's science show which the two loved when they were kids, is still alive and is available for children's parties and events, they invite him to their apartment to perform a show for them, despite them already being physicists. Professor Proton does accept their invite and arrives the next day, but finds performing a children's science show in front of some physicists weird. He also admits that he has become disillusioned about his TV persona, as despite having a PhD from Cornell University, he was never taken seriously by other scientists. He does seem to enjoy doing his show for Penny, to whom he has taken a liking, but when he sees how ignorant she is about science (he even mentions to Leonard how he and Penny even get along because of their different personalities), he loses interest and starts packing up, though he changes his mind when Sheldon and Leonard motivate him by hailing him and his show as the reason they became physicists in the first place. Following this, he suffers a sudden problem with his pacemaker and is admitted to hospital. At the hospital, Professor Proton asks a visiting Sheldon to perform in a Korean child's birthday in his place the next day as he is not well enough to do so. Sheldon is flattered at this and starts considering Professor Proton as his "father", which he reluctantly goes along with.
Meanwhile, Raj asks Howard and Bernadette to take care of his Yorkshire Terrier Cinnamon while he is at the telescope lab during the weekend. They accept, but end up losing Cinnamon while taking her to the park. Despite frantic searching, they are unable to find her. Eventually, she is found by someone else, who contacts Raj. An infuriated Raj then lambastes Howard and Bernadette for losing Cinnamon, but when they find out that he had already found Cinnamon hours before he contacted them, it becomes Bernadette's turn to lash out at Raj for keeping them worried about Cinnamon despite her already been found.
134. “The Love Spell Potential”
With the girls heading to Las Vegas for the weekend and with Lucy busy, the guys decide to spend their time away from their women by playing a game of Dungeons and Dragons with Howard as the dungeon master instead of Leonard for a change. During the course of their game, Raj receives a message from Lucy which says that she is free, prompting him to leave the game and go on a date with her. Their date goes on well until Raj takes exception to Lucy not complaining to the waiter regarding the crab cakes, following which Lucy walks out of their date by pretending to go to the washroom. But when she comes out of the washroom window, she finds herself trapped in a fenced-in area, prompting her to call Raj for help. Raj does rescue her, but then confronts her over her constantly walking out of their dates. He also adds that he loves her because she has more emotional problems than him, following which they kiss.
Meanwhile, back at Leonard and Sheldon's apartment, the guys' game continues. They are interrupted by the girls, who have cancelled their Vegas trip and returned to the apartment, thanks to Amy assaulting a TSA officer at the airport after she "groped" her, which prevented the trio from boarding their flight to Las Vegas. On Leonard's request, they agree to join their game. The game goes on well until Howard asks the characters of Sheldon and Amy to have sex, which makes Amy upset, as she feels that the others are making fun of her non-sexual relationship with Sheldon, and locks herself in Sheldon's bedroom. Sheldon goes over to his room and consoles Amy, explaining that despite them not having sex, he feels that their relationship is "intimate". He also reveals that he has not ruled out having sex with her one day. Following this, they simulate a sex scene with their game characters.
135. “The Bon Voyage Reaction”
Stephen Hawking's team is sending an expedition to the North Sea to find the hydrodynamic equivalent of Unruh radiation. On Howard's recommendation, Leonard joins as a member of the expedition, but is worried about leaving Penny for four months. Penny gives him the green light to go. Sheldon, on the other hand, is jealous of his best friend's new career opportunity and coupled with his fear of being alone for four months, tries to dissuade Leonard from going, to no avail. On Penny's advice, Sheldon decides to drop his hard feelings for Leonard, eventually giving a happy and supportive toast to him at his bon voyage party.
Meanwhile, the guys ask Raj to introduce Lucy to them. Since Lucy is extremely uncomfortable with meeting new people, Raj plans on introducing only one member of their gang to her at first. The honor falls on Amy, the newest member of their group. Although Amy initially handles Lucy reasonably well, Raj begins to demand to know about the status of their relationship, and this causes her to lock herself in the bathroom. Raj eventually asks her to attend Leonard's bon voyage party, to which she reluctantly agrees. But, instead of attending the party, she breaks up with him through a text message while he is at the party, which reduces him to tears. Later, after dropping Leonard off at the airport, Penny goes over to Raj's apartment and tries to console him. When Raj says that he is unlovable, Penny mentions that he is saying that because he is drunk, but then Raj reveals that he did not drink any alcohol since he broke up with Lucy. At this revelation, both of them are amazed and happy, since Raj has finally overcome his selective mutism. The episode ends with Raj talking non-stop about Lucy to the women, much to their annoyance.
The Complete Season Seven
136. “The Hofstadter Insufficiency”
Penny and Sheldon bond during the summer over missing Leonard. Penny calls Leonard, who is partying on the ship and does not sound like he is missing Penny. Penny suggests exchanging secrets with Sheldon, then tells him she appeared topless in an unreleased horror movie. Sheldon says Howard found the clip when they had first met. Sheldon's "secret" is that he does not like YouTube's new rating system. Annoyed, Penny decides to leave, but stays and apologizes when she realizes that she hurt Sheldon's feelings. Leonard shows Penny's movie to his shipmates.
Meanwhile, Raj goes to a university function and talks to Mrs. Davis, who is recently divorced. Though he initially insults her with his inappropriate statements, he gives a sincere apology. Though Raj insists to Mrs. Davis that he is not hitting on her, he later tells Howard he thinks the two had "a moment".
Amy and Bernadette attend the same biology convention and they are surprised when two men buy them drinks. Their relationship is momentarily strained when Bernadette implies Amy's enthusiasm is because of a lack of romantic affection from Sheldon. They make up later, although it becomes awkward when Bernadette says that she would have been attracted to a man resembling Sheldon, and Amy to a man resembling Howard.
137. “The Deception Verification”
Leonard surprises Penny by arriving back early and hiding in her apartment. He asks her to keep it a secret from Sheldon, so they can spend some time alone. Sheldon suspects that Penny is cheating on Leonard when he finds clear signs that someone else is in her apartment. Bursting into Penny's place to catch her in the act, he and Amy find Leonard there. Sheldon gets mad at Leonard for not telling him he is home, and refuses to believe anything he says, although they eventually reconcile with the help of Howard.
Meanwhile, Howard is being affected by his mother's estrogen-based massage cream and becomes emotional and very hormonal. Raj helps him through it using intimate ways, which seems strange to Bernadette.
138. “The Scavenger Vortex”
After the gang blows off Raj's murder-mystery party, he creates a scavenger hunt with ten clues that will lead the winner to the location of a gold coin. They first propose making each couple a team, but Leonard suggests "mixing it up" by picking names out of a hat. Penny gets angry and assumes Leonard has proposed this because he did not want to be stuck with her. The teams consist of Sheldon and Penny, Howard and Amy, and Leonard and Bernadette. Both Penny and Sheldon do well figuring out the different clues as they race around Pasadena. Bernadette becomes very competitive, while Leonard is more worried that Penny is mad at him. Amy and Howard, who have not been alone before, bond over their mutual love of Neil Diamond music.
Finally, Raj reveals that he slipped a gold coin into everyone's pocket, so that they would all be winners. His goal was to teach the value of friendship. To his dismay, Leonard, Penny and Bernadette are angry that, after all of their work, there is no clear winner, and chase him out of the apartment. Howard and Amy abandon the hunt and sing Neil Diamond songs in The Cheesecake Factory.
139. “The Raiders Minimization”
Amy watches Raiders of the Lost Ark with Sheldon. When he asks her what she thought of it, Amy claims that Indiana Jones is superfluous because she thinks the outcome of the story would have been the same with or without him. After spoiling the movie for Sheldon, he tries to find something that Amy loves and spoil it for her. Sheldon watches Little House on the Prairie, Amy's favorite TV show, with her and points out historical inaccuracies. Amy, realizing what he is doing, explains that he should just let her know if he is angry, rather than seeking revenge. He does, and Amy apologizes.
Penny buys the book The Disappointing Child (in which Leonard's mother wrote about his childhood problems), for her psychology class, which upsets Leonard. As a result, Penny goes out of her way to make him feel better and Leonard takes advantage of her sympathy. When Howard finds out about this, he tries a similar technique with Bernadette, but it fails. Bernadette tells Penny about Howard's trick, and Penny, realizing what Leonard has been doing, gets revenge by dressing in a particularly revealing outfit, only to leave a pantsless Leonard talking to his mother on Skype.
Meanwhile, Raj and Stuart prepare profiles of themselves for online dating sites, but none of the women who check them out leave them any messages, leaving them depressed. After realizing that they do not need dating sites, they decide to move on.
140. “The Workplace Proximity”
Amy tells Sheldon that she will be working on an experiment at Caltech and asks Sheldon how he feels about that. Sheldon has no problem with it, until Howard explains that he would not want to work with Bernadette and have to spend both day and night with her. Sheldon withdraws his approval, though Amy tells him that she is still going to take the job. The next day, Amy is even madder at Sheldon when he embarrasses her at lunch in front of her colleagues. At home, Penny and Leonard try and explain to him that Amy is right. Sheldon then goes to Amy's apartment and apologizes, but offends her again when he says she can be difficult to put up with.
Sheldon mentions Howard's comments to Bernadette, who then confronts Howard and gets mad after he tries to deny his statements. As a result, Howard is forced to stay at Raj's place. Later, Bernadette comes over to apologize. Howard promises to spend more time with her, but only after he and Raj finish their video game, enraging Bernadette once again.
At the Cheesecake Factory, both Amy and Bernadette are upset with their significant others. Penny assures them that Leonard will set them straight; however, the guys play video games together instead.
141. “The Romance Resonance”
Sheldon calculates how to synthesize a new, stable superheavy element, but then realizes that his discovery was due to a mistake, which spoils his achievement, making him feel like a fraud. While his friends, co-workers and the scientific community praise him, Sheldon just wants it to stop. Amy finally tells him he is not deserving of the attention, which Sheldon notes is the most romantic thing Amy could ever tell him.
Howard gets everyone to join him in performing a song he wrote for Bernadette, to commemorate the anniversary of their first date. When there is an accident at Bernadette's lab and she is placed in quarantine, Howard and the gang go to the hospital and sing the song for her.
Penny tries to do something romantic for Leonard, after he says that she never does. After failing at finding a romantic thing to do and seeking advice from Raj, Penny tells Leonard that she wishes she could be as romantic as he is. She shows him a box with dozens of mementos – examples of romantic things Leonard has done during their time together. Leonard is shocked, and thinks that the mere fact that Penny has kept all these things is incredibly romantic.
142. “The Proton Displacement”
Sheldon, Leonard and Amy run into Dr. Arthur Jeffries (Professor Proton) at the drug store. Leonard gets an e-mail from Arthur asking him to review his recent paper. As Sheldon wonders why he was not asked, Amy points he comes across as annoying. Sheldon goes to apologize to Arthur, only to annoy him more. The next day, Sheldon informs them that his new friend is another famous TV scientist, Bill Nye "the science guy." After Sheldon and Bill leave, Arthur asks Leonard why he puts up with Sheldon. Leonard explains that whilst Sheldon has his quirks, he is the smartest person he knows, and they both need each other. Though Leonard's answer moves him, Arthur only decides to let Sheldon read his paper after he sees Penny hanging out in the guys' apartment.
Meanwhile, Raj and the girls are making jewelry during girls' night. Howard crashes the party, indirectly upsetting Raj and taking over the jewelry night by offering them better equipment. Howard joins the girls again for another girls' night, leaving Raj feeling left out and unable to explain how he feels about the situation. After Raj mocks Howard, Howard apologizes after finding out how much his feelings were hurt. Feeling bad, Raj makes them lightsaber belt buckles using techniques Howard taught him.
143. “The Itchy Brain Simulation”
While rummaging through their closet, Leonard finds a DVD, which he rented using Sheldon's card, that should have been returned seven years ago. Leonard desperately asks Sheldon not to flip out, and Sheldon shockingly remains calm and agrees. Sheldon makes Leonard wear an itchy sweater until the DVD issue is resolved, so that Leonard can, metaphorically, walk in Sheldon's shoes. Leonard searches for the DVD store (that went out of business years ago), then for the owner (who is deceased), then the owner's next-of-kin (who does not exist), all the while getting a bad rash from the sweater. Sheldon eventually tells Leonard he had discovered the DVD and paid the fine years ago, and that he just wanted him to learn the lesson.
Penny meets Lucy, Raj's ex-girlfriend, at the Cheesecake Factory and gets mad at her for breaking up with him over an email. Lucy calls Raj to have coffee to apologize. Although Raj hopes that they can get back together, Lucy reveals that she is now seeing someone else. Penny then sets up Raj on a date with her friend Lizzy, but Raj ends up freaking out in front of her.
144. “The Thanksgiving Decoupling”
The gang spends Thanksgiving at Mrs. Wolowitz's house, though she is laid up in bed, so Raj, Bernadette and Amy do the cooking. Penny mentions a Thanksgiving she had in Las Vegas with her ex-boyfriend Zack, joking about how they had a "fake" wedding. Her friends tell her that the wedding was real and that she is legally married, causing tension between her and Leonard. Howard tries in vain to bond with his father-in-law, Mike, who instead starts to bond with Sheldon over football; it turns out that Sheldon has considerable football knowledge, as he was forced to watch the game with his father as a child. After Mike shares beers with Sheldon, they continue to hit it off. After insulting Howard, Amy orders Sheldon to apologize to Howard. A now-drunk Sheldon gestures to Amy and says to Mike, "Ain't she great?", then swats her on the rear and suggests she get them more beers. Amy is shocked, but delighted at the physical attention. Meanwhile, Penny has invited Zack over to sign the annulment papers to end their marriage (much to the excitement of Raj, Bernadette and Amy). Zack is at first reluctant to sign, saying he is worried about how ending the marriage will affect their non-existent kids. Penny demands that he sign, which he does. Mike finally compliments Howard, but then attributes his kindness to being drunk. Penny and Leonard reconcile.
145. “The Discovery Dissipation”
Sheldon walks out of an interview with Ira Flatow on NPR's Science Friday after Flatow makes reference to Sheldon's heavy element discovery being accidental. Amy brings Wil Wheaton to talk about how to deal with unwanted fame with Sheldon. Later, Leonard reveals that he was able to disprove the existence of Sheldon's heavy element. This infuriates Sheldon, who has now learned to deal with the fame and feels that Leonard took away the one thing that made him famous. Sheldon's fury peaks when Barry Kripke berates him over Leonard's findings. Sheldon and Leonard argue with each other on Science Friday, while an embarrassed Amy and Penny listen.
While Raj's apartment building is being fumigated, he and his dog, Cinnamon, move in with Howard and Bernadette for a week. Although Raj is very kind and helpful, his presence highlights the deficiencies in Howard and Bernadette's relationship, leading them to argue with each other. Eventually, Raj gets thrown out and he moves in with Leonard and Sheldon. Immediately he starts giving Amy and Sheldon relationship advice and, after he tells Amy she needs to be patient with Sheldon's limits on physical contact, Amy tells him to leave.
146. “The Cooper Extraction”
Sheldon is in Texas to help with his sister's home birth, but as usual is totally self-absorbed and unsympathetic to his sister's discomfort, and no help with anything. In between video calls, his friends wonder what their lives would be like if they never met him (like in It's a Wonderful Life). Penny notes that Leonard would be too afraid to have asked her out, Bernadette envisions that she would not have gone out with Howard because of his strange friendship with Raj, and Leonard speculates that Penny would be living with Zack. Amy suggests that Penny would have tried to seduce Sheldon if Leonard didn't exist, while Howard notes that he would be caring for his mother even after she was dead (like in Psycho), and Raj and Leonard suggest that as roommates, they would have become obese, due to Raj's cooking and Leonard's loneliness. Amy thinks she would have been sad and alone.
After Amy encourages Sheldon to be with his newborn nephew, Raj observes that Amy has had a significant influence on Sheldon. Amy does not believe him, but Leonard shows her that Sheldon has a picture of her on his screensaver. When Sheldon returns home, he tells Amy he would have preferred to have her in Texas with him (or instead of him). At the end of the episode, Howard and the obese Raj and Leonard are at the Cheesecake Factory, where Leonard asks Penny out; she turns him down and reveals that she is dating Stuart, who dresses and acts extremely cool. The scene then changes to reveal that this is Stuart's fantasy, which is he having while sitting alone at the restaurant.
147. “The Hesitation Ramification”
Penny is ecstatic when she gets a minor role on NCIS but is devastated when the scene featuring her is cut. As he is comforting her, Leonard accidentally suggests that her scene would not have made a difference to her career, which upsets Penny. She demands that he honestly tell her his opinion on her acting, and he admits that he believes she has unrealistic ambitions for success. Realizing later that his honesty may have hurt Penny, Leonard brings her an offer to audition for a part in the new Star Wars movie by submitting a video. Penny gets drunk and proposes to Leonard after thinking the only good thing in her life is him. Because Penny is upset and drunk, Leonard hesitates in giving an answer; as a result, Penny leaves, thinking that their relationship might be over.
Raj and Stuart go to the mall to improve their ability to talk to women and end up talking to the security guard.
After realizing no one finds him funny, Sheldon wants to learn how to become more humorous and attempts to develop a theory of universal humor. In the process, he bores Amy by asking her opinion on which words she thinks are funny. Amy meets up with Howard and Bernadette. Bernadette admits to Howard she often fakes a laugh at his jokes.
148. “The Occupation Recalibration”
Penny quits the Cheesecake Factory to devote all her time to her acting career. Despite saying he supports her, Leonard is not thrilled with her quitting. Meanwhile, Sheldon is forced into taking vacation time, and ends up tagging along with Penny. He says he supports her decision, comparing it to himself devoting all his time to becoming a physicist. Leonard eventually says that even though he could not take a risk like hers, he is proud of Penny for doing so.
Bert, a geologist, brings Amy pretty rocks each day as a way of hitting on her. Amy is oblivious until Howard and Raj point it out. Despite telling Bert that she has a boyfriend, Amy is guilt-tripped into attending a "mineral and rock show" with him. Howard and Raj talk to Bert to get Amy out of it, and they end up attending the show with Bert instead.
Bernadette accidentally damages one of Howard's comic books, and heads to Stuart for help. Stuart does not have the issue, and reluctantly refers her to a rival store. The owner, Jesse, insults Stuart, so Bernadette scolds Jesse and leaves without buying the comic. She later returns to Jesse's store alone and continues to berate him, but still purchases the comic.
149. “The Convention Conundrum”
After the guys fail to obtain Comic-Con tickets, Sheldon decides to create his own comic book convention. He decides to ask James Earl Jones, the voice of Darth Vader, to be the celebrity guest at his new event. After finding out where Jones is having dinner, Sheldon approaches him; unlike most of Sheldon's idols, Jones turns out to be a nice guy who is not turned off by Sheldon's obsessive personality and hero-worship. Jones takes Sheldon out for a night on the town, going to an ice cream parlor, a carnival, and a strip club, doing karaoke together ("The Lion Sleeps Tonight"), ringing Carrie Fisher's doorbell and running away, and finally visiting a sauna, where Sheldon begins to get somewhat sick of Jones's company. After he learns that the guys did not get Comic-Con tickets, Jones invites Sheldon and his friends to be his guests and promises to take Sheldon to Tijuana every night.
Meanwhile, Leonard, Raj, and Howard plan to meet with a ticket scalper to get tickets, but chicken out so that they do not get into trouble. The girls go to a tea room to "feel adult", but only mothers and their daughters are there so they move on to the bar and wonder what is so great about being adults since they find that acting like "proper" grown-ups is quite boring.
150. “The Locomotive Manipulation”
Amy plans a romantic Valentine's Day for her and Sheldon by having dinner with Howard and Bernadette on the Napa Valley Wine Train. Sheldon makes a friend who is as crazy about trains as he is, ruining Amy's plan. After she confronts him, Sheldon points out that Amy suggested the trip in the first place, prompting her to confess her trick and say that she "deserves romance." Sheldon gets angry and offers her various sarcastic romantic gestures, including drinking wine, staring into each other's eyes, and kissing; however, the supposedly fake kiss turns into a real one, marking the first time that Sheldon has initiated physical contact between the two. Sheldon even seems to like the intimacy, as he invites Amy to visit the train's engine room with him.
While Leonard and Penny are watching Raj's dog Cinnamon, she eats the chocolates that Penny gave Leonard. They rush her to the vet and are joined by an outraged Raj, who connects with the vet, Yvette, over both owning dogs and their disapproval of what Leonard and Penny did. At home, a surprised Raj sees she gave him her phone number.
151. “The Table Polarization”
Leonard and Penny decide to get a dining table for the apartment so that they no longer have to eat round the coffee table. Sheldon objects to the change, blaming Penny who has changed Leonard though Amy has changed Sheldon. Unhappy with this and that Amy told them about the kiss, he decides to break up with Amy. Amy, who has been alerted, agrees with Sheldon to break up, but stops his plan by convincing him that Leonard is manipulating him. Amy is feeding Sheldon his arguments against Leonard, although goes too far when she suggests they move in together. Finally, Amy and Sheldon eat together on the sofa, with the others at the table, until everyone pities Sheldon and they all end up back at the coffee table.
Howard gets an offer from NASA to return to the International Space Station. He fails to remember the horrible time he had and eagerly wants to go back up. Bernadette holds an intervention where Howard is reminded he would have to go through survival training again. Howard eventually finds a way out by calling his mother during his blood pressure test, which makes him fail his physical exam.
152. “The Friendship Turbulence”
Penny informs the group that she has turned down a role in the sequel to the bad horror movie she was in. Later, Penny's car engine breaks down leaving her no way to get to auditions, so she decides to get her job back at the Cheesecake Factory. Leonard surprises her with a new car, so she can continue progressing her acting career.
After Sheldon insults Howard, Bernadette wants to know why he always insults her husband. Sheldon details a decade of abuse. Howard wants to be a better friend, and invites Sheldon with him on a weekend in Houston where Sheldon can visit NASA and his mother. On the flight, both are frightened by the clear-air turbulence, and each admit that they respect each other as friends and their lives would be empty without each other.
Raj asks Amy to respond to a woman named Emily who contacted his dating web site. This turns off Emily, who thinks Raj is too passive, but she ends up having a lot in common with Amy. Amy has tea with her, until Raj interrupts them, putting off Emily, and ruining any chance of friendship for either of them.
153. “The Mommy Observation”
Sheldon and Howard drop in on Sheldon's mother, but flee after Sheldon sees her having sex. Sheldon returns and gets into an argument, and is sent to his room. After Howard tells him about how he drove away an admirer of his mother, Sheldon apologizes to Mary, saying that he will accept her choices on the outside while condemning her internally for being a hypocrite by going against her religious beliefs. His mother forgives him.
The rest of the gang gets roped into a murder mystery dinner arranged by Raj, with Stuart playing the deceased victim. "Traveling" to the future envisioned by Raj, Leonard and Penny broke up because their successful careers. This leads to an argument over the question of what they would do if one of them were required to give up their dream for the other's success. Stuart tells them that they are the best couple he knows. Penny accidentally reveals she was the murderer, ruining Raj's game. Leonard suggests no matter what happens they all meet in front of the apartment in 20 years to have dinner together. In the future Stuart is the only one who shows up.
154. “The Indecision Amalgamation”
On the subject of decision making, Raj must decide if he is going to date both Emily and Lucy, Penny must decide to accept a role in her horrible horror picture, Serial Apeist 2, and Sheldon is torn between buying a PlayStation 4 or a Xbox One. Sheldon's decision ramblings really annoy Amy both during their dinner date, where she fakes exaggerated interest, and spending hours at Best Buy contemplating his choices. Leonard and Penny talk to Wil Wheaton who is just depressed about the acting industry. After Penny accepts the job, she finds out that Wil plays the bikini clad orangutan she has to wrestle in the film. Emily tells Raj that she doesn't mind him dating someone else and he keeps seeing her.
Meanwhile, Bernadette signs a card for a co-worker who is retiring, but she soon finds out that the woman had been in a terrible accident and the card is a "get well" card, making her message highly inappropriate.
155. “The Relationship Diremption”
Raj and Howard double-date so that the Wolowitzes can meet Emily before Raj scares her off. At first Raj is afraid that Howard is going to joke about his shortcomings; however, Howard ends up to be the butt of all the jokes. He had been on a blind date with Emily years before, and due to a stomach problem, he severely messed up her bathroom and ran out on her. Howard was given the nickname "Clogzilla".
Due to the latest big bang theory discoveries, Sheldon begins to believe he has wasted his life trying to prove string theory. Taking Penny's advice, he decides to get rid of all his string theory books and move on to a new field of study. As he gets frustrated with all of his possible choices, Sheldon jokes that he might as well take up geology, a subject he believes is not real science. Leonard and Penny tell him not to rush into something. Eventually, Amy puts a drunken Sheldon to bed. When he wakes up, he is horrified to see what he holds in his arms: a book on geology. He also discovers that he made many drunk-calls to Stephen Hawking's telephone.
156. “The Anything Can Happen Recurrence”
After reinstating "Anything Can Happen Thursday", Sheldon, Leonard and Penny wander around town looking for a new restaurant. They find Amy and Bernadette having dinner after lying to their friends. They were tired of hearing Sheldon complain about trying to find a new field to study and Penny's complaints about her horrible movie. Leonard agrees with them, so Sheldon and Penny storm off. Bernadette admits she lied to Howard as well. Amy tells Leonard she is jealous of how comfortable Sheldon is with Penny. Penny calls Howard and tells him Bernadette lied to him, but Bernadette says she will just put on a Catholic schoolgirl uniform to make it up to him.
Raj and Howard watch a horror film to prepare Raj to watch it with Emily. They both find the film disturbing. Emily later says that she too finds the film disturbing, but Raj watches it with her after she says it also turns her on.
After dinner, Penny drags Sheldon to a psychic who says all his problems will be solved if he commits more to Amy. In denial of this, Sheldon scoffs at this "malarkey". Later, Amy shows up at Sheldon's door dressed as a Catholic schoolgirl to apologize for lying, all while Sheldon acts unmoved.
157. “The Proton Transmogrification”
The guys prepare for Star Wars Day and plan to watch all six films. Leonard tells Sheldon that Arthur Jeffries (Professor Proton), their childhood hero, has died. While Sheldon is sleeping through the film marathon, Jeffries appears to Sheldon dressed as a Jedi Master. He does not know why he is there or what advice to give Sheldon, so he tells him to cherish the people around him before they die. Penny and Leonard attend Jeffries' funeral, where they start to discuss their regrets in life and Leonard regrets not saying yes to Penny's marriage proposal. After Leonard returns home, Sheldon wakes up and hugs him, taking Arthur's advice. Bernadette and Amy make a Death Star cake for the guys while talking about why they became scientists. Finally, Sheldon has another dream where Arthur asks him if watching Star Wars is a useful way to spend his life and Sheldon sees nothing wrong with it.
158. “The Gorilla Dissolution”
Howard, Bernadette, and Raj are bringing a treadmill into Howard's old room in his mother's house, because of her doctor saying that she needs more exercise. When they reach the top of the stairs, the treadmill slides down the stairs and breaks Howard's mother's leg.
While Leonard visits the movie set of "Serial Ape-ist 2: Monkey See, Monkey Kill", Penny has a disagreement with the director on doing another take and she and Wil Wheaton are fired. Later, Wil, Penny and Leonard commiserate at a bar until Wil gets a call for an audition for Sharknado 2.
Sheldon and Raj go to the movies and they run into Emily who is on a date with another man. Later, Raj and Sheldon discuss why women don't like Raj. Sheldon suggests that Raj has to get over his fear of being alone. Later, Emily stops by Raj's apartment. She tells Raj that the guy she was with did her last tattoo and has been asking her out for months, and that she agreed to go to get it over with. Raj feels much better, and they discuss their relationship as well as Emily's tattoos. Emily then spends the night at Raj's.
Back at home, Penny tells Leonard how she has to make better decisions in her life and suggests that she and Leonard get married. Leonard needs assurance that she isn't just settling for him because she was fired and is feeling sorry for herself. Penny says she realizes that she does not need fame to be happy, only Leonard. Leonard gets down on one knee and formally proposes with a ring, and Penny happily accepts.
After Howard's mother breaks her leg, Bernadette and Howard struggle taking care of her, bickering with each other and realizing what it is like to care for a newborn baby. They take the easy way out and hire a live-in nurse.
159. “The Status Quo Combustion”
Leonard and Penny tell the group that they are engaged, and while they are happy, everyone makes a bigger deal of Raj and Emily having had sex. Leonard's mother is unmoved that he is engaged, but accepts Penny because Sheldon is really fond of her.
Sheldon is angered the university will not let him change his field of study and considers quitting. He is further upset that Leonard and Penny do not want to live with him after they are married. He is disturbed at Amy's suggestion they could live together and his last nerve is broken when he discovers that Stuart's comic book store was destroyed by fire. Sheldon decides to leave town to figure out what he wants. Leonard objects, but Penny says that they should let him go. Sheldon calls Amy to say he is all right, after which a distraught Amy attacks Leonard with a pillow for letting Sheldon go.
Howard's mother keeps driving away the nurses hired to look after her, and even Penny rejects the job. Howard offers Stuart the job, giving him money and a place to stay while he gets back on his feet after losing his store. Stuart loves the job and develops a surprising closeness with Howard's mother.
The Complete Season Eight
160. “The Locomotion Interruption”
Forty-five days after leaving Pasadena, Sheldon finds himself in a train station in Kingman, Arizona with all of his possessions (and his pants) stolen. He calls Leonard to pick him up, and Leonard takes Amy with him. Heading home, Sheldon says that he never left any of the train stations during his journey. Amy is hurt he left without telling her, and that he called Leonard for help. Sheldon is not happy that she is there, and says he did not call her because he was too embarrassed to admit that he could not make it on his own; Amy accepts that he is not perfect. Sheldon thinks his trip was worthwhile because it has left him ready to deal with change, but as soon as he sees Penny's new haircut he immediately walks out of the apartment.
Bernadette gets Penny a job interview with her pharmaceutical company as a salesperson, though Penny is very nervous about it. She does horribly in the interview, but gets the job anyway, after bonding with the interviewer over their shared fear of Bernadette.
Howard and Raj find Stuart still living with Howard's mother even though she has recovered, which is very unsettling to Howard.
161. “The Junior Professor Solution”
Sheldon is allowed to study what he wants in exchange for becoming a junior professor and teaching a class; he is not happy, and nobody signs up for his class because of his reputation. Howard decides to take the class to work on a doctorate, but Sheldon focuses on areas of physics that Howard does not understand to humiliate him. Howard gets him back by being a horrible student leading to an incident where he shoots a spitball into Sheldon's mouth, causing him to be reported to Human Resources. After dropping the class, Howard asks Sheldon engineering questions which Sheldon answers. The men eventually heal by celebrating their own genius, and asking each other questions.
Meanwhile, Bernadette feels Penny should start studying for her pharmaceutical job, but Penny wants to wait, which leads to tension. Amy loves being in the middle, pretending to agree with both of them. Now she can spend time with each one alone, and increase her bond of friendship by trash talking about the other woman and feeling immensely popular. Her good times are short-lived when Bernadette and Penny apologize to each other, and Amy ends up eavesdropping on her friends to see if they are getting along.
162. “The First Pitch Insufficiency”
Howard is asked to throw out the first pitch at a baseball game for the LA Angels of Anaheim, as an astronaut, to celebrate Space Day. Despite practicing, he cannot reach home plate. At the game Howard decides to use a prototype of the Mars rover to deliver the ball, but the Rover moves so slowly across the grass to deliver the ball that Howard is booed by the crowd and his friends in the stands.
Earlier Sheldon and Amy are joined by Penny and Leonard on a double date at a pub, and are baffled when Sheldon says the Shamy relationship is the stronger of the two, because they scored an 8.2 out of 10 on a scientific test used to measure a couple's compatibility. Leonard wants to take the test, but Penny refuses, worried that she and Leonard have nothing in common even though they are engaged. Leonard admits he shares this fear, but says it only strengthens his resolve that they can face it together. Penny is overwhelmed by Leonard's commitment, while Amy wishes Sheldon would say romantic things like that to her. Sheldon tells her that she should trust him that she is already happy because of their test score.
163. “The Hook-Up Reverberation”
Leonard and Penny finally meet Raj's girlfriend Emily, but Penny feels that Emily does not like her. Emily agrees to let Penny practice a pharmaceutical sales pitch on her; however, Emily ignores her pitch. Emily admits she is unhappy that Penny previously hooked-up with Raj. Raj brings the two of them together to talk and Emily apologizes for being rude; however, after the meeting both women part and it is clear that they are still very uncomfortable with each other.
Since Stuart did not get enough insurance money to reopen his comic book store, the men decide to invest in it as part owners. Penny wonders why Leonard wants to discuss finances, while Amy and Bernadette reluctantly accept the investment. Howard's mother has already given the money to Stuart and is calling him by Howard's old pet name Bubula upsetting Howard.
Finally, the men are disappointed that they are not getting a nice comfortable homey place to sit and read comic books, though that is what they are doing in Leonard and Sheldon's apartment.
164. “The Focus Attenuation”
Sheldon claims the men have not invented anything significant recently because they had all been distracted by their girlfriends, so they plan a weekend of brainstorming. The women use the free time to go to Las Vegas.
Reviewing their old brainstorming sessions they find only ideas that involve robot girlfriends. Next they work on the hover board from Back to the Future Part II, but keep getting distracted much to Leonard's frustration. Later at Leonard's lab they have further distractions from the internet and end up back at home watching Ghostbusters along with Leonard.
Meanwhile in Vegas, the women are about to go out when Penny is given some home work by her boss. Bernadette and Amy leave and get drunk. When they return to their room, they find Penny still studying, but take her with them to a strip club, where Amy and Bernadette have fun while Penny keeps studying. The next morning a relaxed Penny heads to the pool and gets her revenge for last night by blinding Bernadette and Amy with the sun from the window while they both deal with extremely terrible hangovers.
165. “The Expedition Approximation”
After Penny gets a company car she sells the one that Leonard gave her in "The Friendship Turbulence", and gives him the money, it bothers Leonard and leads to a conflict between the two. They later share a dinner with Howard and Bernadette to seek their counsel on marriage and finances, but this in turn leads to an argument between Bernadette and Howard over money. Leonard and Penny decide to use it as an example of what not to do in their marriage and finish having sex on the money. Bernadette and Howard eventually make up as well.
Raj and Sheldon see a chance to study dark matter by participating in experiments conducted in a salt mine. To test themselves, they crawl into a hot, sweaty steam pipe tunnel in the university basement with Amy waiting above ground. Sheldon fights several phobias including fear of enclosed places. He also reveals his fear that his new research will fail him like string theory did. Raj consoles him by relating his own fear when he first left India. When some rats show up Sheldon abandons Raj, who later excoriates Sheldon for doing so. Their simulation lasts eleven minutes.
166. “The Misinterpretation Agitation”
Sheldon meets the middle-aged Dr. Lorvis who tracked down a flirty pharmaceutical sales rep, Penny. Leonard explains to him that Penny is his fiancée, so he walks away looking sad. Sheldon invites him inside for a hot beverage. He is a celebrity urinary specialist with a huge memorabilia collection which he invites the men to see. After Sheldon teases that the Penny-Leonard relationship is doomed to fail, Dr. Lorvis locks them in his basement to go after Penny again. He falls for Amy and then Bernadette. Penny explains to him that he is acting creepy, and cannot chase every woman that is nice to him. The girls march him back to let the men out, who are too busy playing Donkey Kong to notice.
Earlier Bernadette tells the girls that she has been picked as one of the fifty most beautiful scientists for an article in a magazine. The magazine cancels the article because Amy wrote an email of complaint about the article since they would not have written about handsome male scientists and are objectifying women. Bernadette claims Amy is jealous because she cannot express her sexuality. Bernadette returns to apologize when she gets hit on by Dr. Lorvis.
167. “The Prom Equivalency”
After finding Penny's old prom dress the girls decide to have a new prom on the roof. Sheldon is worried about the post-prom mating activities that he feels Amy will expect and has a panic attack after he sees how pretty Amy is. Amy reassures him he is under no pressure, but she does hope they will have intimacy one day. She also wants to tell Sheldon something, even if he can't say it back. Sheldon surprises her by saying he loves her. Amy is shocked, then starts having a panic attack of her own.
Howard is not happy since he figures Stuart will bring his mother. Stuart embarrasses him by bringing Howard's second-cousin Jeanie, the girl Howard lost his virginity to. Howard attacks Stuart in the limo for having relationships with his family members. A jealous call from Debbie causes Stuart to abandon Jeanie at the prom. Emily reveals she loves the darker versions of fairy tales, disturbing Bernadette.
Leonard and Penny dance together romantically though no music is playing. They admit that they probably wouldn't have approached each other to dance if they had met at their proms, but are happy together now.
168. “The Septum Deviation”
Leonard announces that he needs surgery in one week because he has a deviated septum. Sheldon is appalled and doesn't want Leonard to have the surgery due to the risks. After Sheldon describes everything that could possibly go wrong with Leonard’s surgery, Leonard tells Sheldon he’ll reconsider it. Leonard then secretly goes to the hospital with Penny after a last-minute earlier appointment comes up and doesn't tell Sheldon, though Amy eventually spills the beans. Sheldon shows up in the waiting room and the hospital experiences a mild earthquake. Sheldon worries about Leonard and runs toward the operating room, hits the glass door and knocks himself to the ground. The next day both Leonard and Sheldon are home with their noses bandaged. Leonard teases that Sheldon only did what he did because he really loves him. Later, Sheldon receives morbid urns he ordered for him and Leonard. However, he is unable to return them because he had gotten them engraved with the morbid messages.
Raj is fretting over finding a gift for his parent’s 40th wedding anniversary until he learns that his parents are getting divorced and his father has moved out. Raj says little things caused them to resent each other over the years. Bernadette and Howard cheer him up, but Bernadette fears the same thing could happen to her marriage. Howard and Bernadette try to say positive things about each other, but it turns into sarcastic bickering.
Note: In lieu of the traditional vanity card at the end of the show, a picture of Carol Ann Susi (the voice of Mrs. Wolowitz, who died during the week) was shown in remembrance.
169. “The Champagne Reflection”
Leonard, Raj and Howard clean out the office of the deceased Professor Roger Abbot and find a bottle of champagne meant to be opened when he made his first great scientific discovery. They take a journal with a bunch of numbers to his coworker Professor Sharpe, who reveals it is just a food diary of how many calories Professor Abbot ate. Abbot believed that he would live forever if he controlled his calorie intake. The men realize not every scientist can make great discoveries, and resolve to drink that champagne in Roger's honor if one of them ever discovers something.
Sheldon prepares his final episode of "Fun with Flags" and reviews highlights of the series including Amy dressing up as a kangaroo, Sheldon dressing up as Betsy Ross, and playing "Fwag, Not a Fwag" with Barry Kripke. LeVar Burton is Sheldon's final guest. No one comments on the series ending until one person posts that he will miss it, causing Sheldon to revive the series and open Roger's champagne in front of Leonard.
Penny and Bernadette attend a banquet for their pharmaceutical company. Their boss Dan is afraid of Bernadette. Penny makes Bernadette realize she has been verbally bullying others. Bernadette goes to apologize to Dan and starts crying when she hears how she's offended her coworkers. Dan feels bad and starts giving Bernadette what she wants again.
170. “The Clean Room Infiltration”
Raj will be unable to host Christmas dinner as his father is coming to town and is depressed about his divorce. Amy hosts a Victorian era Christmas dinner instead. Her traditional party games bore everyone.
Sheldon and Amy have agreed not to exchange gifts, but Sheldon decides to get her one anyway as revenge for the dinner and kissing him in public under the mistletoe. Bernadette takes him to the mall where he gets his picture taken with Santa and a frame which includes a personalized Christmas message to Amy. To his surprise she loves it and gives him a box of Christmas cookies made from his grandmother's recipe, making them both happy and makes Sheldon wonder about the spirit of giving presents at Christmas time.
Meanwhile, Leonard and Howard are working together in a clean lab when a pigeon flies in. They are unable to get the bird out even with Raj’s help. Howard is devastated when he accidentally injures the pigeon with a blast from a fire extinguisher. Leonard tells him how to revive it; however, a crow flies in. Howard and Leonard agree to take the blame for ruining the lab together until Penny convinces them to erase their names off the sign-up sheet for the lab and leave.
171. “The Space Probe Disintegration”
Sheldon and Leonard are excited to play a board game until Amy and Penny say they are tired of doing what the guys want. Sheldon suggests they go clothes shopping since the girls want to do something the guys hate. While waiting, Sheldon mentions that he knows how to compromise because of all he does for Leonard, including still letting Leonard chauffeur him around town, although Amy is teaching him how to drive. Leonard angrily explains how difficult Sheldon can be and that he is not living with Penny, despite their engagement, only for Sheldon's sake. Sheldon apologizes and they both cry over them living apart soon. They decide that Leonard should move out gradually, and Sheldon agrees to let him start spend one night a week at Penny's and let him whistle when he isn't home. Leonard spends the night at Penny's, with Sheldon sleeping on her couch.
Meanwhile, Raj was part of a team that launched the New Horizons Space probe nine years ago, which is going to be activated. A stressed Raj spends the day with Howard and Bernadette and decides to take Howard to a Hindu temple. Howard is surprised Raj leans on religion as a scientist, but agrees to support him when they get to the parking lot. Raj verbally berates a man who dinged his car door, only to calm down when he hears his space probe is fine.
172. “The Anxiety Optimization”
Sheldon has a problem in his dark matter Proton decay research. After Penny says doing a fitness routine she hates motivates her, Sheldon seeks to do the same with his anxiety level while he works. The guys enjoy irritating Sheldon when he asks them to do so, while he annoys the women when he tries to listen to their mindless girl talk. Sheldon becomes exhausted and hallucinates among other things. A frustrated Amy throws him out of her apartment when he focuses on his research and anxiety during their date night. On the bus home he hallucinates a man is really a mix of an Armadillo and Isaac Newton. Leonard and Penny are able to get an exhausted Sheldon to sleep after singing Soft Kitty to him. Sheldon is able to continue his research afterwards.
Meanwhile, Howard has invented a game 'Emily or Cinnamon' where the rest of the friends try and guess whether an embarrassing quote from Raj was said to his girlfriend or his dog. Raj is annoyed, but Emily is okay with it, thinking it is sexy that Raj is sensitive. She kisses Raj and is turned off by the dog hair in his mouth.
173. “The Troll Manifestation”
Leonard has a revelation about Superfluid vacuum and presents his theory to Sheldon who approves. Sheldon writes a paper on their work and they post an online paper together. It is well received except for one troll who makes disparaging comments. Sheldon challenges this person, but panics when he tries to Video call him. Leonard and Sheldon decide to stand up for themselves and are stunned when their harasser is revealed as Professor Stephen Hawking who commented negatively out of boredom and actually liked their paper.
Meanwhile at Penny's apartment the girls spend the night embarrassing each other. They first watch the terrible gorilla movie that was Penny's last acting job. Then Penny finds some video footage of a younger Bernadette in a beauty pageant. And finally Bernadette reveals Amy's romantic Fanfiction of Little House on the Prairie theme about her and Sheldon. The women become invested in the story. Leonard also enjoys Penny reading the fan fiction to him, but stops before a sex scene.
174. “The Comic Book Store Regeneration”
Barry Kripke stops by to thank Amy for helping him with her ideas on string theory, which bothers Sheldon because she never helped him out when he was working on it. He complains to Penny who tells him to "let it go". Instead, Sheldon reveals that Amy was secretly performing experiments on Penny and Leonard and comparing the results with those of a chimpanzee, infuriating Penny.
Leonard and Raj run into Nathan Fillion at a deli, but he denies he is an actor so he can eat in peace. Later, he admits who he is and offers to take a picture with them. Raj asks so many questions to verify Fillion's identity that he looks annoyed in the photo.
Stuart has opened his new comic book store, which impresses everyone except Howard who finds him using the den furniture that his mother had given him. However, all arguments end when Howard gets a call from Florida where his mother is visiting, and receives news that she died in her sleep. Everyone, including Sheldon, goes to comfort Howard. After he and Bernadette leave for Florida, the rest of the gang remember and toast the death of Mrs. Wolowitz, calling her "everyone's mother".
175. “The Intimacy Acceleration”
Amy has read about an experiment claiming two people can fall in love by asking each other a set of personal questions and staring into each other's eyes for four minutes. Sheldon and Penny try it in her apartment. Penny reveals she wishes she was as smart as her friends and Sheldon wishes he had Penny's ability to understand social interaction and letting Penny know the secret that his birthday is that day. They do not fall in love but happily reflect on their friendship. Sheldon is startled when his friends throw him a surprise party when he returns home.
Raj, Emily, Leonard and Amy try a bit of interactive theater where participants have to solve puzzles to get out of a room. The four are disappointed after their scientific skills solve everything in six minutes.
Meanwhile, Howard and Bernadette are at the airport having returned from his mother's funeral in Florida and are outraged the airline has lost her ashes. Howard feels guilty he unknowingly rejected his last chance to spend time with his mother by not driving her to her flight. He is relieved when her ashes are found but Bernadette worries he will put them in their bedroom.
176. “The Colonization Application”
Sheldon and Amy decide to progress their relationship by buying a pet turtle. However, Sheldon changes his mind after it bites him and Amy is hurt when she learns Sheldon has applied to colonize the planet Mars without consulting her. Sheldon doesn't understand why she can't support the opportunity, however Amy makes him realize she wants them to plan their future together. They agree to make another application as a couple and are both amused that if they had children there they would technically be Martians.
Leonard has bought some body paint and a canvas for himself and Penny to have sex on. They are disappointed with the initial results but push themselves into making something they like. They decide to give the canvas to Sheldon by telling him William Shatner painted it.
Meanwhile, Emily leaves Raj alone in her apartment and Raj breaks a drawer while snooping. Raj fails to fix it with Howard and Bernadette listening via video call. Emily is angry, but soon forgives him and gets her revenge by scaring Raj into thinking there is something morbid in her closet.
Note: In lieu of the traditional vanity card at the end of the show, a picture of Leonard Nimoy, who died the previous week, was shown in remembrance.
177. “The Leftover Thermalization”
Scientific American praises the paper Leonard and Sheldon wrote together, but does not mention Leonard's name. Sheldon fails to comfort Leonard over the omission, while Penny tries to cheer up Leonard by doing some online shopping for him.
Meanwhile, Howard, Bernadette and Raj arrive at Howard's mother's home to remove some of her belongings, only to be told by Stuart the power is out. A distraught Howard realizes the last food his mother ever cooked will defrost in the freezer and be ruined. He decides to invite his friends over to eat it all, so it will be like his mother is feeding everybody one last time. At the dinner, Sheldon and Leonard argue about whether an idea's inspiration or execution is more important. Bernadette takes Sheldon and Leonard to another room and scolds them for their bickering. Howard remarks that Bernadette's yelling sounds similar to his mother's, though the others claim to not hear it. Finally, everyone is over-stuffed from eating and lazing around the house. The group expresses mild excitement upon hearing that an online publication has mentioned Leonard's name in connection to the paper, but become much more enthusiastic when Bernadette finds more Tums.
178. “The Skywalker Incursion”
Sheldon and Leonard are headed to UC Berkeley to give a lecture on the paper they wrote together. They decide to drive by Skywalker Ranch and Sheldon wants to go inside, hoping to meet George Lucas. They get past the front gate, but Leonard tells the security guard the truth. Sheldon decides to make a run for it and is hit with a Taser. They are let off with a warning and are forbidden to return. At home Leonard is initially angry, but admits it was a fun adventure and he enjoyed seeing Sheldon get electrocuted.
Meanwhile, the rest of the gang are cleaning out Mrs. Wolowitz's house for a garage sale. A dispute occurs over Howard's Doctor Who's TARDIS. They agree to decide its fate via a Ping pong match with Penny playing for Bernadette and Raj for Howard. Penny starts losing so Bernadette says Raj has to take it can buy it and he starts playing for her with Amy playing for Howard. Amy is about to win until Bernadette says she could have the TARDIS's doors to trick Sheldon into going inside her bedroom. Amy does so, but is disappointed when Sheldon runs into her bedroom dressed as the Fourth Doctor and then leaves.
179. “The Fortification Implementation”
Sheldon is depressed because he was left out of a group attending a symposium at the home of Richard Feynman. On date night he mentions to Amy how his siblings left him out of building a blanket fort as kids. They decide to build their own in the living room and Sheldon has so much fun he agrees to let Amy spend her first night with him in a platonic sleepover. Amy had left a pre-positioned sleepover kit in the apartment just in case.
Wil Wheaton has Penny on his podcast to talk about the terrible movie they worked on together, "Serial Ape-ist 2". Kevin Smith calls to offer her an audition for Clerks III. Leonard, who is not thrilled with her risking her good pharmaceutical job, is stunned when he learns she makes twice the money he does and is being more mature than him. Penny says she will do something immature by going to the audition, tricking Leonard into supporting her possibly acting again.
Howard now owns his mother's house after his father Sam signed it away with no contact. While discussing future plans with Raj and Bernadette, Howard is shocked when he is visited by a half-brother, Josh. Howard wants him to leave, but they bond over Howard being an astronaut and his lustful past with a robotic arm.
180. “The Communication Deterioration”
Raj is working on a proposal for NASA to design a message from Earth and its delivery system to hopefully be found by an Alien life form. He asks the guys for advice and Sheldon and Howard try to take control, so Raj invites only Leonard to work with him. The two realize Sheldon and Howard's ideas were good and ask them to work with them after all. The guys talk about times where they have individually felt excluded from fun group activities while working together on the message. Their message is found by aliens who think Sheldon looks delicious.
Penny is unsure whether she should risk her new career for a chance at acting again and goes to Sheldon for advice. At first Sheldon will not tell her what to do because people think he is too controlling. Penny uses his love of trains in an analogy to get him to say she should go to the audition, but not decide on any major career change yet. Penny's audition goes terribly while she also remembers she hates the petty environment around other actresses. Penny thanks Bernadette for getting her the good pharmaceutical job and takes her (and Amy) on a special dinner after Bernadette's prodding.
181. “The Graduation Transmission”
Leonard has been asked to give the graduation speech at his old high school in New Jersey and is excited to bring Penny with him; however their flight is cancelled due to bad weather. Penny arranges with the school to broadcast Leonard's speech over Skype and buys him a "sexy graduate" costume for a graduation cap and gown. Leonard's speech starts out boring so he changes it as he reflects on his own high school life. He explains to the smart and forgotten kids that after they graduate the world will find them far more interesting than the popular students.
Raj has bought a quadcopter, but is unable to get it to work so he brings it to Howard and Sheldon. Raj's father is outraged at the cost of it so he cuts off Raj's allowance; however, Raj is able to leverage his parent's divorce as a way to get them both to separately send him more money. Howard tears the helicopter apart, but is unable to get it to work. The guys begrudgingly call tech support like Bernadette suggested. While on the phone the helicopter activates itself after receiving a random signal and flies wildly around the apartment terrorizing everyone.
182. “The Maternal Combustion”
Sheldon and Leonard are getting an award for the paper they wrote together and both their mothers are in town to see the ceremony. Both mothers focus on Sheldon making Leonard jealous. He is also irritated when Sheldon tells Penny her engagement ring is really a recycled and recut diamond drill bit. Beverly wonders why Leonard and Penny haven't set a wedding date, while Mary is fine with them waiting. The mothers also get into an argument after Beverly describes Mary's religious beliefs as a superstition. Beverly later reflects with Sheldon that perhaps there are other ways to raise children than she did. The mothers make up and Beverly tries to show affection by hugging Leonard, though it is awkward for both of them.
Meanwhile, Howard and Bernadette have moved into Mrs. Wolowitz's house with Stuart still living there as well. Bernadette is tired of the other two and Raj lying around so she makes them clean the kitchen. Raj points out to Howard that Bernadette acts like his mother. Howard tries to clean the kitchen like an adult but does a poor job. The three men continue cleaning while singing "It's the Hard Knock Life" from the musical Annie.
183. “The Commitment Determination”
On the fifth anniversary of their first date, Sheldon offends Amy by debating whether he should watch The Flash instead of focusing on her. Sheldon doesn't understand why she and others think their relationship has moved too slowly, pointing out Leonard and Penny still haven't made any wedding plans. Amy says she needs time away from him to rethink their relationship, leaving Sheldon unsure of what to do with the engagement ring he bought for her.
After deflecting Sheldon's questions, Leonard and Penny decide to elope in Las Vegas. While driving there, wanting to start their marriage with a clean slate, Leonard admits he drunkenly kissed another woman two years ago while on the boat in the North Sea. Penny is upset but appears to forgive him as they weren't engaged then.
Howard and Bernadette want Stuart to move out, but always find a reason not to bring it up. They finally get up the nerve to tell him, only to back off when they realize it is his birthday.
Raj is spooked out by Emily's latest morbid idea: having sex in a graveyard. While having a picnic there, he says they are very different people and it appears he wants to break up, but when Emily confronts him he instead says he loves her.
The Complete Season Nine
184. “The Matrimonial Momentum”
Leonard and Penny go through with their plan to elope in Las Vegas and have the ceremony broadcast via livestreaming so their friends can watch it at home. Leonard created a touching science-based wedding vow while Penny recites "You've Got a Friend in Me". After Leonard carries Penny over the threshold and they start kissing, Penny is still bothered by Leonard's kissing another woman two years ago and is outraged when she learns the other woman, Mandy, works with Leonard, and when they return home, she goes to her apartment alone.
Sheldon is confused and hurt about Amy's indecision about their relationship, and insults her while the friends have gathered to watch the wedding at Howard and Bernadette's house. Amy officially breaks up with him, causing everyone except Howard and Stuart to leave and due to being the only ones remaining, the two men catch the end of the wedding. Amy later rebuffs Stuart. Sheldon calls his mother to send back his great-grandmother's ring he had meant for Amy, but Mary tells him to wait things out.
Sheldon briefly considers dating Mandy to get back at Amy, but cannot be with someone attracted to Leonard even though Penny is. Sheldon is angered that Penny knew that Amy was unhappy and did not defend him, and storms out. A dejected Leonard cannot believe he is spending his wedding night with Sheldon, though Sheldon says he always expected it.
185. “The Separation Oscillation”
After having a nightmare of Sheldon and Penny passionately kissing, Leonard considers marriage counseling but finds it too expensive. Howard and Bernadette knew what Leonard did with Mandy Chow two years ago, leaving Raj annoyed Howard did not tell him. Bernadette also conceals this from Penny, but points out that Leonard has changed over the years, as he is confident now and with Penny because he loves her and not out of desperation. Leonard has a chat with Mandy, who feels no attraction to Leonard and neither remembers nor cares about kissing him in the first place. But while talking with her, Leonard realizes part of him may be trying to sabotage his marriage because he thinks he is not good enough for Penny. Penny confesses part of her is scared he will leave her for someone smarter. She and Leonard agree move past their fear and embrace their happiness. Sheldon surprises them with a trip to San Francisco, only to immediately announce he will also be going, as he bought the tickets for himself and Amy.
Sheldon returns Amy's belongings, failing to make her jealous by "accidentally" including one of Penny's bras in the box. He records an episode of "Fun With Flags" alone, angrily talking about countries that have separated as a metaphor for Amy dumping him. Amy is furious and demands he remove the video, but Sheldon takes it as a sign she still wants him.
186. “The Bachelor Party Corrosion”
Raj and Howard plan to kidnap Leonard to a secret location for the weekend as a belated bachelor party and forcefully take Sheldon with them. Meanwhile, the women have a small bachelorette party at Penny's apartment.
Though Sheldon irritates Raj and Howard, he is impressed that the van in which they are driving belonged to physicist Richard Feynman, and that their plans are to stay at his vacation house in Mexico. When the van experiences a flat tire, a stuck lug nut prevents the men from fixing it. They try several scientific methods to remove it, each of which is unsuccessful, ultimately inadvertently setting the van on fire.
Amy reveals that she has not told her family about her and Sheldon's breakup, explaining her intimidation by relating how her mother would make her sit in a "sin closet". Penny decides to pierce Amy's ears for her, and mentions that she has not told her family she married Leonard. She reluctantly calls her father Wyatt, who is simply happy for her, though he upsets Penny telling her that he accidentally killed her pet pig a year ago. The women cajole Amy into calling her mother, but when Amy finds it difficult to tell her mother about the breakup, Penny takes it upon herself to blurt out to Amy's mother about the breakup, the penis cookies and Amy's pierced ears. As a result, Amy's mother makes her sit in Penny's closet.
187. “The 2003 Approximation”
Leonard and Penny finally tell Sheldon they have moved in together now that they are married. Sheldon is upset, but Bernadette says he should try and find another roommate, though Stuart firmly rejects her idea that he move in with Sheldon. Sheldon rejects everyone he meets and Amy refuses to live with him, as they have just broken up. Sheldon tries to pretend that it is 2003, before he met Leonard, Penny and Amy, and before he developed emotional connections to other people, fearing that Leonard and Penny will eventually abandon him as well. For his sake, Leonard and Penny agree to split their time between apartments to be with Sheldon who begins to modify The Roommate Agreement for this purpose.
Meanwhile, Stuart wants a band to play music in his comic book store for free. Raj and Howard write a filk song about Thor fighting Indiana Jones, though Emily suggests it would be better if people could dance to the music. Raj and Howard momentarily break up the band but quickly make up, playing the song at the store only to have Stuart say they should play music people could dance to.
188. “The Perspiration Implementation”
Howard builds a machine to add mileage to the Fitbit Bernadette buys to track his exercise. Leonard, however, decides that the group should become more active and they take up the sport of fencing, attending a class taught by Barry Kripke. After learning that Amy is single, Kripke wants to ask her out, which upsets Sheldon. The men go to a sports bar and encourage Sheldon to move on. Sheldon randomly asks two women out and is rejected.
Stuart asks Penny, Bernadette, and Amy for advice on how to attract more female customers to his comic book store and they conclude that his creepy behavior is the problem. Amy sympathizes with him for being lonely, but turns him down when he hits on her. She also rejects Kripke after he sends her a photograph of him nude. When Leonard and Sheldon return home from the bar, they run into Amy and Bernadette, leading to a chat between Sheldon and Amy, who awkwardly exchange anecdotes on their attempts to move on.
189. “The Helium Insufficiency”
Swedish physicists are about to prove Sheldon and Leonard's super-fluid hypothesis about the universe and the men need liquid helium to conduct their experiment first. Kripke refuses to let them use any of the university's helium. Howard connects them to Kenny, a black market dealer, though Sheldon's mistrust of him almost ends the deal. At the lab, Leonard and Sheldon panic about using stolen property and pay Kenny to take it back. Kripke offers to give them some of his helium if they share scientific credit with him. Instead, they pay Kenny for helium a third time and watch Ernest Goes to Jail with him because he gets along with Sheldon.
Meanwhile, Stuart tells the rest of the group he has been on two dates thanks to an app on his phone. They download it on Amy's phone much to her discomfort and make fun of the suggested men. To their surprise, a man named Dave texts Amy his thanks for the date they had last night. Amy reveals she has been on three coffee dates with men and is starting to like Dave.
190. “The Spock Resonance”
Wil Wheaton arranges for Sheldon to be interviewed for a documentary about Spock and Leonard Nimoy by his son Adam. Sheldon explains he admired the character of Spock from childhood for being unemotional and tried to imitate him. He brings up the autographed napkin from Nimoy from "The Bath Item Gift Hypothesis" that he keeps with his valuables, including the engagement ring he meant for Amy. His aborted proposal to Amy shocks Leonard and Penny who push Sheldon to admit he is feeling hurt. Sheldon lashes out, but decides to propose to Amy anyway for closure. From a distance he sees her kiss another man, Dave, goodbye outside her apartment building, Sheldon leaves dejected. At home he is upset Spock's way of life is a lie and Leonard tells him to start focusing on the real people in his life.
Meanwhile, Bernadette wants to start renovating the house though Howard protests changing his childhood home. Calling in her father Mike, he asks why Howard does not want children. Howard reveals Bernadette to be the one resisting parenthood. Raj theorizes she fears it because Howard acts so childish. Howard says he always dreamed of being a responsible father to make up for his own abandonment in childhood. Bernadette promises to think about it.
191. “The Mystery Date Observation”
Amy has another date with Dave, so Bernadette and Penny decide to spy on her, dragging Leonard along. During the date, Dave reveals he is a huge fan of Sheldon's scientific work. He asks her about Sheldon the entire time, greatly annoying her. As they leave, Bernadette hits Dave's car. Initially outraged about the accident, Dave meets Leonard and is instantly starstruck. Amy ends it with Dave, who is happy to have kissed and been rejected by the same woman as Dr. Sheldon Cooper.
Meanwhile, Sheldon struggles to move on without Amy, so he asks Howard and Raj to set him up with another woman since they introduced him to Amy. They post an ad on Craigslist that is filled with scientific and sci-fi brain teasers to solve for Sheldon's contact information that night. Fifteen seconds after the deadline, a woman named Vanessa shows up, sharing many of Sheldon's interests including physics, flags, and obscure languages. He does like her, but shuts the door on her for missing the time limit.
192. “The Platonic Permutation”
Sheldon and Amy decide to try and be friends and spend Thanksgiving day at the aquarium together. Despite initial awkwardness and annoyances, Amy answers Sheldon's questions about her dating life honestly and they agree they want the other one to be happy. They fall back into their old bond as friends. Later, Amy calls Sheldon and asks to be his girlfriend again. Sheldon declines, explaining that getting over her was too difficult, and wishes to remain friends. Amy hides her hurt feelings over this.
Bernadette, Raj and Emily drag Howard to a soup kitchen to volunteer for the day. Howard is irritated at washing dishes, but is shocked when he meets Elon Musk, the founder of SpaceX. They bond over space travel.
Meanwhile, Leonard and Penny prepare Thanksgiving dinner when Leonard realizes Penny does not know his birthday. He then proceeds to list personal things he knows about her, but accidentally reveals he knows she hates an orange lingerie he once bought her, something she never told anybody but only wrote in her journal. As an apology for reading her journal without permission, Leonard wears the lingerie and dances around for Penny, asking her to post an image of him in the lingerie on her social media as punishment. Penny refuses, but Howard, Raj, Bernadette, and Emily catch Leonard wearing the lingerie when they barge into his apartment.
193. “The Earworm Reverberation”
Sheldon is humming the melody to a song of which he does not know the name, especially unusual because of his eidetic memory. He spends two days obsessing over the tune and recording a log while he is still mentally sound, fearing he might be turning into a mad genius, thus annoying Leonard and Penny. Sheldon finally realizes the song is "Darlin'" by the Beach Boys and that the lyrics relate to how Amy made him a better man. He rushes to her apartment.
Amy calls Dave for another date at her place, though Bernadette cautions that could lead to intimacy. Although Dave brings up Sheldon again, the date goes well and they kiss once as Sheldon arrives to profess his feelings. With Dave's help, Amy realizes Sheldon loves her and wants to get back together. She agrees and they kiss passionately. Dave then asks Sheldon if he wants to discuss physics, only to be kicked out of her apartment.
Meanwhile, Howard and Raj's fan page for their filk band is liked by a person named Trent. They stalk Trent online and think he is very cool, deciding to go meet him only to run out when they see Trent pick his nose and eat a booger.
194. “The Opening Night Excitation”
After an iconic Star Wars-like opening credit crawl, the men are overjoyed to get opening night tickets to the Star Wars: The Force Awakens movie, which premieres on Amy's birthday. Sheldon still wants to see it, despite Penny saying he should be with Amy. Sheldon has a dream/visitation where Arthur Jeffries' ghost talks with him while dressed as a Jedi master, and convinces him Amy is more important. Talking over birthday gift ideas with Penny and Bernadette, he shocks them by saying he is going to have coitus with Amy to show her how much she means to him. On Amy's birthday, Sheldon and Amy are nervous about having sex, but enjoy the experience more than they expected. Sheldon wants to do it again on her next birthday which is fine with Amy. Arthur later appears to Sheldon again asking for details, but Sheldon only wants to discuss the movie.
Meanwhile, the rest of the men go to the movie with Wil Wheaton, who arrives dressed as Spock in a Star Trek uniform. After the movie, the men lie back in the afterglow, much like Sheldon and Amy did.
195. “The Sales Call Sublimation”
Penny cannot find a way to make a sales call on psychiatrist Dr. Gallo. She has Leonard pose as a patient to get her in the door. Dr. Gallo disagrees with the way Leonard's mother approaches psychology. Leonard feels great talking with her. When Penny meets her, Dr. Gallo has her question why she often acts like a mother to Leonard, along with her other anxieties such as Sheldon. She also makes Penny feels better after their talk. Dr. Gallo gives her a prescription, but not the one Penny was supposed to sell.
While Amy is at a conference, Sheldon spends the day at the astronomy lab with Raj and they discover a medium-sized asteroid. They argue about what to name it; Leonard suggests they name it after their girlfriends. Sheldon gets Raj to name it after Amy in exchange for any children Sheldon and Amy have being named Rajesh, even their daughters.
Howard and Bernadette want to start remodeling the house and are excited when Stuart moves out, but are surprised when they also miss him. Stuart sneaks back at night to watch them sleep.
196. “The Empathy Optimization”
While Amy is still away, Sheldon has recovered from the flu, but, though his friends attempt to help him, his rude behavior during his illness offends them. They decide to rent a party bus to Las Vegas to get away from him. Amy admits she extended her trip to avoid him as well, and teaches Sheldon about empathy. After Sheldon realizes what he did was wrong, he apologies to his friends, but his apology to Emily goes wrong when he says dermatologists are not real doctors. When Raj tries to defend Sheldon, it leads to a fight between him and Emily. Sheldon decides not to go to Las Vegas with the group in order as a gesture of his regret, but sneaks on the bus with Stuart to make amends with Emily and soothe things between her and Raj. Sheldon and Stuart then leave, but the others decide to let Sheldon and Stuart on after all.
197. “The Meemaw Materialization”
Sheldon's grandmother "Meemaw" visits Pasadena to check out Amy. Meemaw distrusts Amy due to their breakup and lets slip that Sheldon had planned to propose. Both Sheldon and Amy tell Meemaw how they make each other a better person, so Meemaw tells them that she won't stand in their way.
Meanwhile, Raj has a debate about Frozen with Howard, attracting the attention of Claire, a bartender working on a sci-fi screenplay for a children's film. She asks Raj to meet her for a scientific perspective on her story's plot. Raj wants to do this, but Howard and Bernadette warn it could upset Emily. Raj is unsure where things are going with her, but eventually tells Claire he has a girlfriend. Claire says they can still meet as two platonic adults. However, at the meeting, Raj fantasizes about having a family with Claire.
198. “The Valentino Submergence”
Leonard and Penny go out to eat for Valentine's Day and realize that they are getting older after Penny is addressed as "Ma'am." Howard and Bernadette plan on using their new hot tub and find a rabbit floating in it. After nursing it back to health and naming it Valentino, the rabbit bites Howard, who heads off to the ER for a rabies shot. Bernadette decides for the moment not to tell him that she is pregnant.
Raj finally decides to break up with Emily and then calls Claire, who has just gotten back together with her old boyfriend. Emily won't take him back, sending Raj into a depression. Sheldon and Amy host their first live episode of "Fun with Flags." Taking live phone calls, wherein Amy ends up speaking with Raj and Barry Kripke about their love lives, thoroughly depresses Sheldon. Amy does get Sheldon to admit their own breakup has made them a stronger couple. They are interrupted by Penny and Leonard who barge in dressed as cupids, throwing confetti in an effort to feel young again.
199. “The Positive Negative Reaction”
Bernadette tells Howard she is pregnant. While he is excited at first, Howard begins panicking that he will be a bad parent. Talking things over with the men, Sheldon is upset that a baby will change their social group. The others try to calm him down at a karaoke bar and come up with a possible way for him to make more money by expanding on Sheldon and Leonard's research and patenting the idea. A drunk Sheldon says that, because he and Howard both grew up without fathers, Howard will know how important he is for his own child.
Meanwhile, Bernadette meets with the women to tell them, though Leonard texts Penny beforehand. She is worried by Howard's reaction, but Amy and Penny tell her life will be better with a child. Bernadette shocks them by admitting the baby was conceived on Sheldon's bed. After their ideas for fun are all impossible to do because Bernadette is pregnant, the men invite them to sing karaoke with them. Howard and Bernadette soothe each other's fears. Everyone takes turns singing about babies to Bernadette, while Sheldon is shocked to learn what happened in his bedroom.
200. “The Celebration Experimentation”
When Amy plans a birthday party for Sheldon because he made her birthday so special, he is reluctant on account of a traumatic childhood experience in which his sister's friends lied to him that Batman was coming to his sixth birthday, thereby ruining his birthday thereafter. Nonetheless, he relents and the friends hire TV's Batman, Adam West, to attend as their present. When Sheldon arrives, he is initially happy, but quickly panics and runs into the bathroom. Penny tries to talk to him and they open up to one another. He emerges to apologize to everyone, after which Amy and all assembled share a toast in Sheldon's honor. Sheldon is delighted to hear all the nice things said about him. They then receive a video call from Professor Stephen Hawking, who joins them in singing Sheldon "Happy Birthday to You."
201. “The Application Deterioration”
Sheldon, Leonard, and Howard move forward with patenting their superfluid helium idea, but are shocked to learn that the University automatically claims 75% of any profits and that Howard is not legally entitled to any profits. They reluctantly agree to sign, allowing Sheldon to write their own contract to share the money from the remaining 25% with Howard. Bernadette is against this, as Sheldon belittles Howard every time they try to work together. When confronted with this, Sheldon agrees to make it part of the contract that he be respectful of Howard for the purposes of the patent. Sheldon also shows his generosity by stipulating that 1/4 of his profits will go to a scholarship fund for the Wolowitz baby.
Meanwhile, Emily sends Raj a belated Valentine's gift and wants to see him again. Raj turns to the women for advice, but decides to go through with seeing her after they say he shouldn't. On his way there, Claire calls him to say she is now single and he should see her instead, since Emily is just manipulating him. Raj drives back and forth while talking to both women, unsure of whom he should see, before choosing Emily and ultimately sleeping with her.
202. “The Solder Excursion Diversion”
While Leonard and Howard work in Howard's lab, their wives join them and help them with their project. After leaving to pick up more solder, the two men are invited to see a preview of Suicide Squad and decide to lie to their wives and attend. Howard spitefully texts Raj, unaware that he is in the lab with the women. Raj is ready to help the women out their husbands' lie, but the men show up with flowers and an apology.
Sheldon's old laptop finally dies so Amy buys him a new one. He does not want to dispose of the broken one and takes Amy to a storage facility where he discloses that he has never thrown anything away, including clothes, broken electronics and toothbrushes. Amy now feels closer to him. Sheldon sends her home so he can Skype with her in bed on his new, high resolution laptop.
203. “The Big Bear Precipitation”
Amy convinces Sheldon to go with Leonard and Penny to spend the weekend in a cabin in the woods. Sheldon is phobic of everything in the outdoors. After their hike is rained out, they play Never Have I Ever where Sheldon exposes Leonard's bank account that he kept a secret from Penny. Penny gets mad, but reluctantly understands. She admits she is unhappy in pharmaceutical sales, but also doesn't want to go back to acting or waitressing. She resolves to stay with the job in order to be an adult and pay off her credit card debt. Sheldon admits he was arrested once in a jaywalking incident and Amy once pushed all the buttons in an elevator.
Raj is getting too involved with Bernadette's pregnancy by giving advice and buying a huge teddy bear. Howard tells him to back off until Bernadette gets upset and wants him and the bear back. He does so and the three listen to the baby's heartbeat, though Raj gets a little too close again.
204. “The Viewing Party Combustion”
As the group prepares to watch Game of Thrones at the apartment, Leonard refuses to go to Sheldon's quarterly roommate agreement meeting and is further annoyed when Penny takes Sheldon's side. Amy arrives and agrees with Leonard, stating her dislike of meetings for their relationship agreement. On the way there, Raj constantly brags about dating both Emily and Claire, annoying Howard. Stuart shows up in costume because Howard tricked him into wearing it. The group splits with Sheldon, Penny, Raj and Stuart in one apartment and Leonard, Amy and Howard across the hall. Leonard is further upset to learn Penny goes behind his back to Sheldon to get what she wants in the roommate agreement. Amy only took Leonard's side because she is jealous of how close Sheldon and Penny are. Howard accidentally eats peanuts and has to go to the hospital after an allergic reaction. He is all right and the group compare all their scheming to the characters on the Game of Thrones series. The men later make fun of Stuart riding home on a bike while still in costume.
205. “The Fermentation Bifurcation”
Penny wins a wine-tasting trip from work, so everyone but Sheldon and a pregnant Bernadette joins her. Raj is still dating both Emily and Claire, but is not exclusive with either and decides to bring Claire, asking his friends not to bring up their relationship status. They meet Penny's old boyfriend Zach, who questions the military potential for Leonard and Howard's navigation system. This worries them, but Howard decides he still needs the money for his baby, so they move forward. Zach also flirts with Claire and questions why Raj isn't more committed to her. Claire tricks Raj into admitting he is seeing someone else in addition to her.
At home, Sheldon bores Bernadette with his love of trains and different types of toast, but she does enjoy a version of Dungeons & Dragons where her character is not pregnant and can enjoy alcohol, sushi, and hot tubs. She thanks him for a fun break from her pregnancy.
206. “The Line Substitution Solution”
Leonard has Penny pick his mother Beverly up from the airport to avoid her and then attend a Q&A. Penny tries to bond with her, but is subjected to her analytical and condescending remarks and feels lost when Amy and Bernadette talk science, bonding in front of her. Beverly offers to interview Amy, Bernadette, and their significant others for a new book on high-achieving couples, but sees no point in interviewing Leonard and Penny. By now, Penny is completely angry with Beverly, has had enough and expresses her feelings of being insulted and Beverly reveals that she herself was insulted when nobody invited her to or even told her about Leonard and Penny's wedding. Penny suggests they have another small ceremony for Beverly and they bond.
Sheldon hires Stuart to go shopping with Amy for him so he can keep his own place in line for the Q&A session with the guys. Amy is annoyed and pays Stuart to yell at Sheldon and also rejects Sheldon sending Stuart with flowers and an apology. Stuart holds Sheldon's place in line while Sheldon goes to quickly give Amy an apology himself. However, Sheldon's experience is ruined when another man joins his friends in the line ahead of Sheldon and nobody else gets upset about him "cutting."
207. “The Convergence Convergence”
When Leonard and Penny announce their second wedding ceremony, conflict arises between Leonard's parents, Beverly and Alfred. Sheldon has also invited his mother, Mary. Beverly and Mary are distant with each other, while Beverly and Alfred bicker. While the Hofstadters snipe at each other during dinner, Mary and Alfred bond over their dislike of Beverly and leave early, since they are staying at the same hotel. Sheldon and Leonard are later worried when neither parent will answer their phones that night, though Penny is amused at the thought that their parents are becoming closer.
When Howard and Raj get an e-mail from the U.S. Air Force about the newly-completed guidance system, Howard fears the government is after them, due to negative portrayals of them in the media. Bernadette tries to convince him that he is paranoid, but Howard's fears increase when he sees a car following them to dinner, unaware that it is Leonard and Penny. His attempt to evade them causes him to drive recklessly, and to be pulled over by a policeman who gives him a sobriety test.
The Complete Season Ten
208. “The Conjugal Conjecture”
The gang prepares for Leonard and Penny's second wedding ceremony. Sheldon and Leonard fear that Mary slept with Alfred the previous night, though they swear nothing happened. They do, however, plan to visit each other, irritating Beverly. Penny's family arrives. Her mother worries that her son's recent jail stint will cause Leonard's family to think of them as white trash. The ceremony goes well, with Leonard and Penny declaring their love for each other, Beverly and Alfred grateful they at least made Leonard together during their relationship, and Sheldon declaring his love for the couple. Howard is contacted by Colonel Richard Williams of the Air Force Research Laboratory, who scares both him and Raj. Howard eventually agrees to meet him, but the colonel refuses to give the reason for his interest.
Title reference: Everyone assuming Mary and Alfred slept together.
209. “The Military Miniaturization”
Leonard and Howard worry the military might try to take over the guidance system project for weaponry, but Sheldon does not. They make him promise not to talk during the meeting with Colonel Williams. The Colonel is impressed with Howard as the main brain behind the project, making Sheldon squirm. The military wants a smaller version made, perhaps in four months. Sheldon, no longer able to contain himself, promises to have it in two. Though the others are angry about such a tight deadline, they all have fun with their new lab's retinal scanner. Meanwhile, the pharmaceutical company employees have found out Bernadette is pregnant, infuriating her as they might take her off the next big medical project. Penny admits she was the one who let this slip. Bernadette forgives her because she intends to threaten her boss with a lawsuit if she is taken off the project.
Title reference: The military wanting a smaller version of the guidance system.
210. “The Dependence”
Transcendence Sheldon, Leonard, and Howard are exhausted from trying to meet the Air Force's deadline that Sheldon set into motion. In a dream, The Flash persuades Sheldon to take an energy drink. After it wears off, Sheldon is convinced he is addicted, further annoying the other two. Sheldon breaks down and admits he cannot figure out the math and is not as smart as he thought. The others comfort him. Facing Colonel Williams, they admit that they need at least two years, which is easily accepted as the military is used to contractors not meeting deadlines. Amy takes Penny to a party thrown by Bert the geologist, but they discover they are the only ones there. Bert shocks them by saying Amy is the most popular scientist at Caltech. Raj tries to help Bernadette get the nursery ready, but she admits her lack of excitement makes her fear she cannot be maternal. Raj calls his OB-GYN father, who tells Bernadette that, while she may not like babies in general, she can still love her own child.
Title reference: Sheldon trying to beat his perceived caffeine addiction.
211. “The Cohabitation Experimentation”
After a plumbing problem makes Amy's apartment uninhabitable for five weeks, Leonard and Penny suggest Amy move into Leonard and Sheldon's apartment. After Amy proposes their cohabitation as an experiment, Sheldon agrees to move with her into Penny's apartment, thrilling Leonard and Penny. Amy's first night in Sheldon's bed is rough and she does not get much sleep due to Sheldon's tossing and turning. To celebrate their first night alone without Sheldon, Leonard and Penny dance in their underwear in their apartment. The next morning, Sheldon and Amy fight over scientific integrity, working themselves up until Amy suggests they head for Penny's apartment to make out. After an ultrasound, Howard and Bernadette are angry that Raj knows the sex of their baby when they had elected not to find out. They have a bad night debating whether to call Raj about it.
Title reference: Sheldon and Amy agree to experiment with living together.
212. “The Hot Tub Contamination”
Amy and Sheldon storm into Leonard and Penny's apartment arguing about Sheldon requiring a bathroom schedule. To help him cool off, Penny takes Sheldon to an ice cream parlor, where he tries to hunt for a different romantic partner. Sheldon confesses that he once walked in on his father with another woman when he was thirteen, which is why he always knocks three times when entering a room now, and it makes him worry that he will hurt Amy one day. Penny convinces him to give the relationship a chance. Leonard coaches Amy on how to live with Sheldon. Returning, Sheldon agrees to compromise, so he does away with the bathroom schedule and agrees to share a toothbrush holder, a big step for Sheldon. After a canceled weekend away, Howard and Bernadette find Raj and Stuart secretly coming into their house and using the hot tub. They listen in as Raj reveals he is now single, but finally kick them out when Stuart says he is not wearing a bathing suit.
Title reference: Raj and Stuart secretly using Howard and Bernadette's hot tub.
213. “The Fetal Kick Catalyst”
Sheldon throws a brunch to surprise Amy, who wanted to invite guests over; Stuart, Bert from the geology lab, and a Romanian neighbor from downstairs attend. Stuart is insulted when he learns that the brunch was a test run before inviting others over; Sheldon apologizes and they get drunk, complimenting each other and annoying Amy. Penny gets invited to a Van Nuys Comic-Con event to sign autographs since she starred in two Serial Apeist movies; she is humiliated by fans deriding her poor acting ability but loving her topless shower scene. Leonard ends up holding court describing how he married such an attractive woman. When Howard finally feels the baby kick, he and Raj go shopping for a crib and test-driving a minivan for 24 hours, but Howard injures his back and they drive to the ER.
Title reference: Howard's spending spree after feeling the baby kick for the first time.
214. “The Veracity Elasticity”
Sheldon finds out from Leonard through Bernadette that Amy's apartment was repaired two weeks ago and that Amy lied about it to keep living with him. Leonard learns from Howard through Bernadette that Penny has been secretly moving Leonard's collectibles into storage. As Penny covers for Amy over her lie, Sheldon and Leonard confront them for lying to them. Sheldon forgives Amy and wants to keep living with her, but is torn about where he really belongs, especially after having a nightmare of Leonard and Penny turning his old room into a sex dungeon. He chooses to live with Amy after engaging in an intellectual conversation with her. Leonard also agrees to let Penny decorate their bedroom to make her feel more at home, but when she makes the room look too girly, he puts some of the stuff into Sheldon and Amy's new closet.
Title reference: Amy stretching the truth about her old apartment not being habitable.
215. “The Brain Bowl Incubation”
Amy uses skin cells from her and Sheldon to produce some primitive neurons through transdifferentiation. This inspires Sheldon to want to have a child with Amy, though she is not enthusiastic about his plan to have a child immediately. Sheldon launches a plan to seduce his girlfriend. Raj becomes attracted to Issabella, a cleaning woman at his lab, and fixes her dinner. She is insulted when she discovers that Raj told his friends that she was a fellow astronomer, but agrees to another date.
Title reference: Sheldon and Amy mix their DNA and incubate some brain cells.
216. “The Geology Elevation”
Sheldon learns that Bert has won a MacArthur Fellowship prize for his work on endolithic organisms and has to deal with his professional jealousy, repeatedly injuring himself while trying to cope. The rest of the group discuss their own internal jealousies. Professor Hawking calls Sheldon and explains that even he gets jealous. In order to make peace, Sheldon goes with Bert to a taping of The Ellen DeGeneres Show. Meanwhile, Howard finds a remote-controlled miniature Stephen Hawking he once built and, while everyone (except Kripke) thinks it is offensive, Hawking would actually like the idea.
Title reference: Bert's geology research gets more attention than Sheldon's work.
217. “The Property Division Collision”
After Sheldon and Amy take the ugly portrait of Penny and Amy to Leonard and Penny's apartment, the guys start to divide up their belongings. When Sheldon tries to take everything, a dispute over the official apartment flag starts a war between Sheldon and Leonard. Sheldon rents out his old room to an old man, Theodore (Christopher Lloyd), who helps them to realize that Sheldon moving out is affecting both of them deeply, leading Sheldon to acquiesce regarding the flag. Stuart brings Howard and Bernadette a gift and ends up moving back in because he was evicted from his apartment. Stuart helps them with baby things to justify his moving in, starting a war with Raj who claims he was first in line to help them. Finally, Bernadette goes into labor and everyone heads to the hospital for the arrival of the baby.
Title reference: Leonard and Sheldon's dispute over dividing their belongings.
218. “The Birthday Synchronicity”
The impending birth of Bernadette and Howard's baby coincides with Amy's birthday, which interferes with Sheldon and Amy's annual sex date. Raj accidentally reveals the baby is a girl and is kicked out of the Wolowitz house. When the time comes for the baby to be delivered, everyone waits in the lobby of the hospital. The friends all reminisce about how much has changed in ten years, though Raj feels he has done the least, which further upsets him. Halley Wolowitz is born and Raj is honored to be her godfather. The baby's cry sounds like her grandmother, Debbie Wolowitz. After going to The Wizarding World of Harry Potter, Amy and Sheldon finally have their annual birthday coital festivities.
Title reference: Halley Wolowitz is born on the same day as Amy's birthday.
219. “The Holiday Summation”
After the Christmas holiday, Sheldon and Amy tell Leonard and Penny about their visit to his mother Mary, who upset Sheldon by confessing she never thought he would find a partner. Sheldon reacted by acting anti-socially and getting his ear pierced. Also, Leonard and Penny had a series of mishaps chopping down a Christmas tree and bringing it home, while Bernadette and Howard have been struggling to cope with a constantly screaming baby. Eventually, Bernadette does resolve the problem by climbing into Halley's crib and sleeping with her.
Title reference: The couples tell stories that summarize what happened to them during the holidays.
220. “The Romance Recalibration”
Penny feels Leonard is not putting enough effort into their relationship now that they are married. Leonard thinks that he is the only one putting in any effort at all. Angrily, Penny takes Amy with her to a spa weekend in lieu of Leonard. Sheldon and Leonard soon follow, solving the problem by having Sheldon create a Relationship Agreement for Leonard and Penny just like Sheldon and Amy's. Meanwhile, Howard and Raj create a path in the baby's room to the crib without causing the floorboards to squeak, thus disturbing baby Halley, with an overly complicated solution.
Title reference: Leonard and Penny reorganizing their relationship for more romance.
221. “The Emotion Detection”
AutomationSheldon wants to understand others' emotions better and gets an experimental machine from MIT that reads other people for him. It reveals Leonard is angry about Penny inviting her ex-drug dealing brother to stay with them while he applies for a job at her pharmaceutical company. Sheldon is upset the machine works so well, as he feels he cannot understand others himself, but Amy comforts him, proud of his progress. Leonard and Penny apologize for blaming their fight on him, while Penny still intends to blame Leonard to her family as the reason why Randall cannot stay with them. Meanwhile, after being dumped by his latest girlfriend, Raj calls together several of his ex-girlfriends to find out why he is still single. Emily Sweeney, Lucy, Claire, and Emily the deaf woman tell Raj that he has been pushy, vain, needy and too scared of his parents and subsequently leave him feeling down, since they all found better relationships after they dumped him. Howard promises that, if things do not work out with Bernadette, he will become Raj's partner in thirty years.
Title reference: Sheldon's machine prototype to reveal emotions.
222. “The Locomotion Reverberation”
Sheldon, Leonard, and Howard are nearly finished with their guidance system for the military, but Sheldon thinks it could be even smaller, frustrating the others as they have just met the approved specifications. To distract him for a few days, Leonard gifts him a trip to be a train conductor in Nevada. The trip greatly excites Sheldon, becoming all he thinks about, frustrating Amy. After seeing Sheldon's theory, Colonel Williams orders his smaller version to be made instead (he actually points at the Schrodinger equation), so Leonard and Howard try and get him to come back, but he refuses, saying that theory can never be proven, unlike trains. After Sheldon sees through their attempt to trick him into correcting a purposely wrong equation, Howard promises to teach him the mechanics of trains in exchange for his help, also allowing him to build the smaller guidance system with them. Meanwhile, Penny and Amy take Bernadette out to get her mind off motherhood duties, leaving Raj and Stuart to babysit Halley. However, Bernadette becomes worried about Halley when Raj and Stuart repeatedly call her while having a few minor mishaps and the fact that Bernadette now has a big house and a family of her own has made Penny and Amy sad over the slow progress in their own relationships.
Title reference: The consequences of Sheldon's train trip taking over his thoughts.
223. “The Allowance Evaporation”
Sheldon and Amy are out on a date when Bert the geologist is stood up. He says he admires them other than their only having sex once a year. Amy is angry Sheldon told everyone at the university. Sheldon apologizes, now understanding the need for privacy, and also informs Amy of one of his private secrets: that he got his driver's license two years ago, but lets her chauffeur him to feel important. Meanwhile, Raj's father has stopped trying to find him a wife since Raj still relies on him to pay for everything. Raj's friends make him realize he is spoiled. Raj decides to stop taking the money to prove everyone wrong, though his father is very happy.
Title reference: Raj stops taking money from his father.
224. “The Comic-Con Conundrum”
Raj appoints Sheldon as his financial manager and is told he cannot afford to go to San Diego Comic-Con this year due to his high rent and massive credit card debt. Raj tries selling his collectibles and working for Stuart to make extra money. Howard does a bunch of chores so Bernadette will let him leave for five days. Penny says she wants to go with the guys to make Leonard happy, but they both think she will be miserable, leading to tension until Sheldon and Amy reveal the truth. Howard and Bernadette try to pay Raj for babysitting Halley, but he rejects the money along with his chance to go. Leonard decides to stay home to be with Penny and Howard does the same for his family. Sheldon still plans on going, confounding Amy with his attempts to have her join him.
Title reference: Raj, Howard, and Leonard's struggles with going to Comic-Con.
225. “The Escape Hatch Identification”
Identification Raj can no longer afford his apartment, so Leonard and Penny temporarily give him Sheldon's old room. This makes Sheldon uncomfortable and he calls Beverly to have her analyze why. She claims he views his old room as an escape hatch should things go wrong with Amy and that Leonard and Penny need a roommate to distract themselves from their own relationship problems. The group's fighting leads to Raj leaving and scaring Howard, Bernadette, and Stuart in the middle of the night. The couples are able to work through their issues and Raj is invited back to stay with Leonard and Penny.
Title reference: Leonard's mother helping Sheldon find his metaphorical "escape hatch," his old room in Penny and Leonard's apartment.
226. “The Collaboration Fluctuation”
Sheldon and Amy attempt to analyze the Copenhagen interpretation using the neurobiology of decision-making. Professionally collaborating for the first time, they try to be nice for the sake of their relationship, but their work is of poor quality. They find that insulting each other makes them more creative, so they compile a list of topics on which insults are allowed. Meanwhile, Penny and Raj bond over girly things, causing Leonard to feel left out. Howard and Bernadette suggest that he talk to them, but Raj and Penny talk over Leonard about his feelings.
Title reference: Sheldon and Amy collaborating, first through cooperation, then through arguing.
227. “The Recollection Dissipation”
Sheldon pushes himself to work on the guidance system with Howard and Leonard and his project with Amy on the same day. He catches a cold and wakes up the next day, half-naked and with no memory of what he did after he took cold medicine. His notebook of classified information on the military project is gone. Tracking his phone, they discover that Sheldon went to a Western-themed bar. He gets the notebook back, but learns he told everyone there about the project after making them pinky swear to secrecy. Amy then performs Soft Kitty for Sheldon in different languages using an autoharp. Meanwhile, Bernadette feels guilty about returning to work so soon and leaving Halley. Howard thinks she is mad at him for not telling her her aunt died six years ago, but makes her feel better by saying that they can change their choices if they want and Halley will not remember this anyway.
Title reference: Sheldon losing his memory of the day.
228. “The Separation Agitation”
Bert the geologist interrupts the latest "Fun with Flags" episode to tell everyone he has a girlfriend now, a personal trainer named Rebecca. He brings her to meet the gang, but it becomes clear that she is only with Bert for his grant money. They convince him to dump her. However, he misses her, calling "Fun With Flags" again to say that he got her back by purchasing her a jet ski. Meanwhile, Howard, Bernadette, and Stuart are all upset about leaving Halley at the university's daycare. Howard and Stuart take her out the first day to go to an aquarium and bring Bernadette with her to see her off to daycare the next day.
Title reference: The agitation felt by separating from baby Halley.
229. “The Cognition Regeneration”
Sheldon loses his edge at online gaming and tries several new tasks to keep his mind sharp: baking with Raj, juggling with Howard, and riding a unicycle. Amy says maybe he should just focus on living well. Sheldon does agree with her, but also wants to try stilts. Penny runs into her ex-boyfriend Zack, who offers her a job at his menu company. Penny likes the idea and Leonard reluctantly supports her, despite having reservations about their previous relationship and her potential choice of careers. Penny calls Zack to accept the job but says he cannot, as his fiancée is not fond of the idea of him working with his ex-girlfriend, leaving Penny to concede to Leonard. Meanwhile, Howard is tired of Bernadette making fun of his magic tricks and finds her old ventriloquist dummy, though she uses it to scare Howard.
Title reference: Sheldon trying to keep his mind sharp.
230. “The Gyroscopic Collapse”
Leonard, Howard, and Sheldon finish their gyroscope for the Air Force, only to have it confiscated by the military for classified reasons. The loss of the project causes Howard to become clingy with Bernadette, though he reminds her that she has behaved in a similar manner after setbacks at her own job. Raj moves out of Leonard and Penny's apartment and into a room above Bert's garage. Amy is offered a summer position as a guest researcher at Princeton. Though Sheldon initially takes the news badly, he ultimately agrees she should accept the offer, and they have a night of unscheduled sex before she leaves.
Title reference: The loss of the gyroscope project.
231. “The Long Distance Dissonance”
With Amy away, Sheldon's old admirer Dr. Ramona Nowitzki begins to hang around him at Caltech and, later, his home. The rest of the gang become convinced she is pursuing Sheldon, alarming Amy. They do their best to keep her away from him, even following her to her car after dinner as a group. Sheldon does not believe Ramona is romantically interested in him but, when he asks her about it, she kisses him. Sheldon immediately departs and flies to New Jersey, proposing to Amy the second she answers the door.
Title reference: Sheldon and Amy's long-distance relationship problems.
The Complete Season Eleven
232. “The Proposal Proposal”
Amy enthusiastically accepts Sheldon's marriage proposal. However, when dining with Amy's colleagues later that night, Sheldon is offended that they are more impressed with Amy's work than his own. With help from Stephen Hawking, Sheldon later comes to grips with the fact that he will not always be the center of attention in the marriage. Bernadette is shocked to realize that she is pregnant again. She and Howard are not thrilled at the idea of having another baby so soon after their first. They attempt to convince Leonard and Penny to have a child as well, but are rebuffed.
Title reference: Sheldon's proposal of marriage
233. “The Retraction Reaction”
Leonard gives an interview on public radio where he admits physics research might be at a dead end. The university is furious and, while trying to think of reasons to put in a retraction, he depresses Sheldon into thinking he might be right. Penny asks Howard and Raj come over and help the two but end up just as depressed. Getting drunk with Penny, the men go to the grave of Richard Feynman and realize there is hope for physics as long as they believe in it. Leonard accidentally sends a drunken email to Human Resources, which bemuses Mrs. Davis. Meanwhile, Amy and Bernadette agree with each other to keep quiet about the success in their careers so as not to upset Sheldon and Howard. While bragging to each other, they end up arguing which of their fields is better.
Title reference: Leonard's depression while writing a retraction of his statements on the radio.
234. “The Relaxation Integration”
Sheldon cannot find the perfect wedding date and begins talking in his sleep, adopting the persona of a laid-back person who goes with the flow. Amy and Penny believe that his subconscious mind is trying to tell him to be more relaxed; his attempt to be so while wearing flip-flops ends in disaster. He decides to leave all the wedding planning to Amy. Meanwhile, Raj and Stuart both become interested in Bernadette's new coworker Ruchi. While she likes them both as friends, she does not want a relationship with anyone.
Title reference: Sheldon trying to embrace the relaxed side of his personality.
235. “The Explosion Implosion”
Howard and Bernadette learn their second child will be a boy, leading Howard to doubt whether he can be a good father to a son. He and Sheldon go out in the desert to test launch a model rocket, but it explodes, causing him further doubt. On the way home, Howard does a good job coaching Sheldon to drive them home, for which Sheldon tells him he will be a good teacher to his son. Leonard's mother Beverly begins talking to Penny as a friend and confidant, troubling Leonard, especially when he learns that Beverly told Penny that she was proud of her, a level of praise she never bestowed upon Leonard himself. When Leonard confronts Beverly, he is touched when she says that of all of her children's spouses, Penny is the one by whom she is most impressed and that, for this, she is indeed proud of him. Meanwhile, Raj helps Bernadette turn baby girl clothes into boy ones.
Title reference: The fate of Sheldon and Howard's model rocket.
236. “The Collaboration Contamination”
Amy and Howard begin collaborating on a neuroprosthetics project, upsetting Sheldon and Raj, who feel they are not spending as much time with them. When they seek solace with an annoyed Bernadette, she exploits the situation to trick Sheldon into doing Howard's chores. Penny successfully employs the approaches recommended in one of Bernadette's parenting books to deal with Sheldon, but Leonard believes she is coddling Sheldon too much. Sheldon and Raj resolve the issue of missing their significant others by spending time together.
Title reference: Amy and Howard's collaboration contaminating Sheldon and Raj's moods.
237. “The Proton Regeneration”
Professor Proton, Sheldon's favorite childhood show, is being rebooted. After unsuccessfully auditioning for the part, he goes to Wil Wheaton for acting tips for his second audition. However, Sheldon is later dismayed when Wil is offered the role instead. Talking it over with Arthur in his dreams, he is still upset to see his idol replaced and considers Wil an enemy again. Meanwhile, Howard gets a vasectomy while Bernadette is on bed rest. Penny offers to take care of Halley for them, but they insult her by expecting her to be irresponsible. Halley ends up saying her first word by calling Penny "Mama."
Title reference: The announced reboot of the Professor Proton series.
238. “The Geology Methodology”
Bert asks for Sheldon's help in a geology research project relating to dark matter. Sheldon secretly agrees, but is too embarrassed to admit he is working with rocks. Bert finds out about this and ends their partnership. After talking with Amy, Sheldon goes to apologize, only to find Leonard has taken his place. Meanwhile, Raj runs into Ruchi again and goes out with her, but she does not believe in romantic love. After Howard and Bernadette tell Raj that he can just have sex with Ruchi, he agrees to keep it casual.
Title reference: Sheldon working in geology with Bert.
239. “The Tesla Recoil”
After learning Sheldon went behind their backs to work with the military again, Leonard and Howard say Sheldon is like Thomas Edison, taking credit for others' ideas, while they are more like Nikola Tesla. Leonard and Howard bring in Barry Kripke to help create a better idea than Sheldon's, but Kripke goes to the military himself, cutting all three of them out. Meanwhile, Bernadette fears Ruchi is trying to steal her projects at work while she is on maternity leave and enlists Raj to spy on her. Though he finds proof that Ruchi may be stealing from Bernadette, Raj tries to defend Ruchi like a boyfriend would, pointing out Bernadette's hypocrisy as she would most likely have stolen from other people's projects as well. Ruchi is not happy about this and promptly dumps Raj.
Title reference: The men's discussion of Tesla and Edison.
240. “The Bitcoin Entanglement”
In 2010, Leonard, Howard, and Raj mined a lot of Bitcoin, now worth thousands of dollars, but left Sheldon out due to his fear of tax implications. Flashbacks are shown of how the Bitcoin ended up on an old laptop of Leonard's, which Penny gave to her old boyfriend Zack after she and Leonard broke up (though the Bitcoin is initially thought to be on Howard's laptop). Leonard allows Penny to have his laptop during a dinner with Howard, Raj, and Sheldon at the Cheesecake Factory. In 2017, Leonard and Penny retrieve the computer from Zack, who first shows them a video of a drunken Penny apologizing for breaking up with Leonard; when an eavesdropping Sheldon asked why she dated Leonard, she said that it was because he was a great guy; she also said that she believed they would someday end up married but she was not ready for it yet. Leonard is moved by this revelation. The Bitcoin is not found on the laptop. Sheldon explains he had moved it to a flash drive on Leonard's keychain to teach the guys a lesson, but Leonard reveals that he lost the keychain years ago, leaving Sheldon embarrassed at his error. A final flashback to 2013 shows Stuart discovering the flash drive, which he decides to erase and sell for $10.
Title reference: The men trying to find their old Bitcoin investment.
Notes: Carol Ann Susi posthumously appears as Howard's mother in this episode using archived audio.
241. “The Confidence Erosion”
When Raj misses out on a job at the planetarium, his father says he has no confidence because Howard always makes fun of him. Raj distances himself from Howard and later gets the job. Howard is hurt by this (even after apologizing to him) and tries to make amends with Raj after his first performance at the planetarium but, when he sees him get a date, he leaves without speaking to him, thinking that the latter's life is better without him. Meanwhile, Sheldon and Amy try randomly dividing up wedding tasks, but they keep arguing. The only thing they can agree on is to get married, so they decide to just get married at City Hall instead. However, Sheldon decides that he wants a first dance with his new wife and they go home to plan their wedding.
Title reference: Howard eroding Raj's confidence.
242. “The Celebration Reverberation”
Howard and Raj are still fighting, so Howard dis-invites Raj to Halley's birthday party. However, when Stuart pulls out as party planner at the last minute, Raj agrees to plan the party, which does not turn out too well due to Halley being asleep, Bernadette being on bed rest, and no people turning up. When Howard and Raj get into a shoving match in the party's bounce house, they end up letting out their frustrations, but also having fun and reconciling. Leonard is depressed upon receiving his successful brother's Christmas card and attempts to make a list of what he and Penny accomplished this year, not coming up with much. This prompts them to think about their plans for the future, so they decide to go on trips and achieve more out of life together before starting a family. Sheldon cooks Amy a Little House on the Prairie-themed birthday dinner, which gives them both food poisoning. They eventually recover enough to attend Halley's birthday party with the others, where they have fun in the bouncy castle and then have sex in Howard and Bernadette's house.
Title reference: Amy and Halley's birthday celebrations.
243. “The Matrimonial Metric”
Sheldon and Amy struggle to choose a best man and maid of honor from their friends. They secretly decide to test and score them, allowing everyone to have an equal shot at either role. Once the gang finds out, none of them apart from Bernadette and Stuart want to be in the wedding. Sheldon settles for Stuart as best man but, once Leonard tells Sheldon that, as the groom, the decision is his alone, he picks Leonard. Amy is set to call Bernadette, but once Penny realizes Amy is her best friend, she immediately pitches herself for the position and Amy enthusiastically chooses her.
Title reference: Sheldon and Amy scoring their friends for roles in the wedding.
244. “The Solo Oscillation”
With Leonard, Howard, Raj, and Amy accomplishing so much on their respective projects, Sheldon is forced to admit he has nothing important upon which to work. He makes Amy leave the apartment for a few days so he can focus, but cannot come up with any ideas and calls his mother as a distraction. Leonard and Amy have fun recreating experiments from when they were growing up, boring Penny, so she eats with Sheldon as he mulls over his scientific studies. Penny helps him realize that his study of dark matter is his rebound science from string theory, which Sheldon admits he never truly disregarded, but explaining string theory to her inspires Sheldon, helping him discover a potential breakthrough in the field. Meanwhile, Howard is too busy with his family to be in the band with Raj, so Raj brings in Bert. But when Howard annoys Bernadette by writing an astronaut-themed musical while she is on bed rest, she makes him rejoin the band. The three are poorly received at a Bar mitzvah after singing Bert's original song about the boulder from Raiders of the Lost Ark.
Title reference: A triple entendre to represent Sheldon going into isolation to figure out his future research field only to go back to studying string theory, the vibration of the strings in string theory, and Howard's oscillation between being in a band with Raj and being solo.
245. “The Separation Triangulation”
Raj hooks up with a recently separated woman, Nell, after one of his lectures at the planetarium. Her husband, Oliver, confronts Raj at the planetarium and then breaks down over the end of his marriage. After comforting Oliver, Raj talks to Nell and convinces her to give her husband another chance. Meanwhile, after diving once again into string theory and sprawling his work across his and Amy's apartment, Sheldon approaches a reluctant Leonard and Penny and convinces them to let him use his old room to study for a three-day trial period with an agreement to be quiet and stay out of their way. Sheldon surprisingly sticks to this agreement, being a reasonably good guest, which shockingly frustrates Leonard to no end. After Leonard lets out his frustrations, Sheldon then renegotiates the guest tenancy agreement for an extra few days and resumes being his normal demanding self, much to Leonard's relief.
Title reference: A double entendre that refers to both the love triangle between Raj, Nell, and Oliver, who is upset at his separation from Nell, and the roommate triangle that has reformed between Sheldon, Leonard, and Penny, a distinct callback to the show's initial seasons.
246. “The Novelization Correlation”
Sheldon and Amy are surprised to find that Wil Wheaton's new Professor Proton show is actually very entertaining and that Wil had Howard on as a guest. On Howard's suggestion, Sheldon apologizes to Wil, mending their friendship, and tells him he wants to be on the show, but Wil asks for Amy. Sheldon tells her to do it, but she says she often does not do things to avoid upsetting him. Sheldon is horrified when he realizes how selfish he has been, especially when he finds out that the men do the same for him. Sheldon encourages Amy to go on the show to inspire girls to pursue science, even while trying to control his obvious jealousy for her. Meanwhile, Leonard writes a book about a physicist that solves a murder, basing the protagonist Logan Dean on himself and writing romantic tension between Logan and his mean boss Illsa. He lets others read his draft to seek their opinion. Bernadette points out that Illsa is similar to Penny, who thinks it is based on Bernadette, though Leonard does not correct her. However, Bernadette tells Penny the truth, upsetting her and making her mad at Leonard. After calling his mother for advice, Leonard learns that he inadvertently based Illsa on her, but abandons the book when he becomes disturbed at the romantic context.
Title reference: The uncertainty of on which woman in Leonard's life he subconsciously based the mean boss character in his novel.
247. “The Neonatal Nomenclature”
Bernadette's due date arrives, but she still has not given birth. As Amy and Howard work together at the college, the rest of the friends try various ways to induce her labor, though Sheldon wants to play a complicated board game to help her pass the time. Amy shocks Howard by saying Bernadette has already decided to name the baby after her father, Michael. He does not agree and everyone makes suggestions as to what to name the baby. Bernadette goes into labor and gives birth to a son named Neil, after Neil Armstrong, Neil Gaiman, and Neil Diamond, with Michael as the middle name.
Title reference: The naming of Wolowitz son before he is born.
248. “The Athenaeum Allocation”
Sheldon and Amy decide on a wedding date of May 12th. They want to have their reception at the Athenaeum at Caltech. While scouting the location, they are shocked to see Leonard and Penny eating there, as Leonard had told Sheldon their application had been denied. In reality, Leonard just wanted a place to avoid Sheldon. Kripke has booked the venue for his birthday party on the same day as the wedding. Leonard cleans radioactive sludge for Kripke to get the date for Sheldon as an apology for lying. Kripke eventually agrees to change the day but, when Amy hears he wants to sing at the wedding, she suggests they get married at the Griffith Observatory instead. Meanwhile, Bernadette and Howard are unsure if one of them should quit his or her job to stay home with the children. Howard volunteers but, when left alone with the children, he passes out exhausted, leaving Raj in charge. When Bernadette meets Penny for lunch, she realizes that she loves being at the office again, but does not want to leave the children. She and Howard promise to figure it out later after they take a nap.
Title reference: The Athenaeum date being allocated for Kripke's birthday instead of the wedding.
249. “The Gates Excitation”
The men are excited that Bill Gates is visiting Penny's pharmaceutical company, although she says that she cannot bring them along. Sheldon believes that it is an April Fools' Day prank. Leonard sees what hotel Gates is staying at on Penny's schedule, so he, Raj, and Howard meet him in the lobby the day before. Once Sheldon sees proof, the men twice send him to the wrong hotel as real pranks. Penny says Leonard can meet Gates for real, so he fakes being sick to avoid him. When Penny puts Gates on a video call, he recognizes Leonard from the previous night. Meanwhile, Amy is tired of Bernadette only talking about her children, so Bernadette uses her expanded parental brain to learn random science facts.
Title reference: The men being excited to meet Bill Gates.
250. “The Tenant Disassociation”
After Sheldon has a food truck moved away from the building, Leonard and Penny are shocked to discover he is the leader and sole member of the Tenants' Association for the building. Amy does not want to be caught in the middle but secretly suggests they rally support from the other tenants to vote Sheldon out. No one else supports Leonard, so Amy tells them Sheldon was never added to the lease when he moved across the hall with her. Sheldon fires back with his own legal technicality, so Amy is forced to support Leonard. She makes Sheldon happy by suggesting he be Leonard's official opposition, making Leonard doubt himself. Meanwhile, Howard and Raj find a drone in Howard and Bernadette's hot tub. With Stuart's help, Raj returns it to the cute owner Cynthia and gets her number. Unfortunately, Cynthia watches footage of Raj on the drone and is immediately turned off.
Title reference: Sheldon leaving the Tenants Association.
251. “The Reclusive Potential”
Sheldon has been writing to reclusive scientist Dr. Wolcott (Peter MacNicol) who invites Sheldon to visit him in his completely isolated mountain cabin. The women quickly ask Leonard, Raj, and Howard to tag along with him, making this his bachelor party, despite Sheldon's assertions that it should not be called such. Wolcott has a brilliant mind, but his strange behavior unnerves the guys. He tells Sheldon he cut off all contact with others to focus on science. Though Sheldon enjoys the science, he decides that he does not want to live like Wolcott because of his friends and his love for Amy; the guys then leave to avoid Wolcott. Meanwhile, Penny and Bernadette throw Amy a quilting bee for her bachelorette party, which she quickly finds boring. When Amy tells them she wants a night full of bad decisions as she earlier implied, they go to a bar where Amy drinks a few shots and passes out in twelve minutes. When she wakes up back at the apartment hungover and disappointed, the women lie and reassure her she had a wild time, involving her drunkenly river-dancing.
Title reference: Sheldon considering the scientific potential in living as a recluse.
252. “The Comet Polarization”
After Neil Gaiman tweets about Stuart's comic book store, it becomes very popular and the crowds upset Sheldon. Stuart hires an assistant manager named Denise and she impresses Sheldon with her comic recommendations. Amy goes to her for information on comics to connect to Sheldon but, when she tries to tell him, he says he has talked enough about comics with Denise. The store's popularity causes Stuart to be unable to babysit for Howard and Bernadette's date night. They try to have another date at home, but Stuart shows up so they hurriedly go out. Meanwhile, as Raj sets up a telescope, Penny sees a new comet. Raj takes sole credit for the discovery, angering Penny. Leonard tries to defend her, but feels sorry for hurting Raj's career. Penny confronts Raj herself and he agrees to share credit after Penny does not give in like Leonard.
Title reference: Raj and Penny polarized over who deserves credit for discovering the comet.
253. “The Monetary Insufficiency”
Sheldon needs half a billion dollars to prove his latest concept of string theory, which the university cannot afford to fund. Crowdfunding and selling some of his most valuable comic books to Stuart give him a small start. When Raj mentions gambling in Las Vegas, Sheldon goes there, but is caught calculating odds by security before he can make any bets. Meanwhile, Amy takes Penny and Bernadette shopping for her wedding dress. She loves an old-fashioned one that the other girls admit that they find ugly, though Penny assures Amy that she can make her own decisions about her wedding. Sheldon, however, comes home and sees Amy in the dress and loves how she looks.
Title reference: Sheldon not having enough money for his miniature black hole experiment.
254. “The Sibling Realignment”
Sheldon's mother Mary refuses to attend his wedding unless he invites his older brother George, with whom he is no longer speaking. Sheldon and Leonard fly to Texas to talk to George, who now owns a chain of tire stores. He refuses to attend and later explains to Leonard and Sheldon that the family sacrificed a lot to fund Sheldon's education and he was stuck caring for their mother and sister Missy after their father died while Sheldon was at college. Sheldon never thanked him for this. Leonard takes George back to the hotel room where Sheldon apologizes for what he did and the brothers reconcile. George agrees to attend the wedding. Meanwhile, Howard and Bernadette's children contract pinkeye, infecting everyone except Penny, much to Amy's fury.
Title reference: Sheldon and his brother making amends.
255. “The Bow Tie Asymmetry”
Sheldon and Amy's wedding day arrives, with many friends and family attending, including Amy's domineering mother (Kathy Bates) and quiet father (Teller), Sheldon's mother Mary, brother George, and sister Missy, who is pregnant with her second child and separated from her husband, and Mark Hamill, who replaces Wil Wheaton as officiant as a favor to Howard, who returned his lost dog. Sheldon cannot get his bow-tie to be symmetrical and conversations with Amy and his mother give him an epiphany about superasymmetry. Sheldon and Amy, along with Leonard, get caught up figuring out the math of the theory during the wedding ceremony, making Hamill take Star Wars questions to stall for time. Penny retrieves the couple, who then decide that they have the rest of their lives to make science together. Amy and Sheldon express their vows. Amy recites a set of heartfelt vows, leaving Sheldon initially at a loss for words before he reciprocates her loving speech. They are pronounced as husband and wife while Kripke sings in the background.
Title reference: Sheldon's bow-tie remaining asymmetrical.
The Complete Season Twleve
The Final Season
256. “The Conjugal Configuration”
Sheldon and Amy go on their honeymoon, starting with Legoland California and then travelling to New York City. Sheldon's insistence on scheduling their marital relations stresses Amy. He says he only does it to remind himself to be intimate with her. They compromise by letting him make a schedule without sharing it with her. Leonard and Penny discover Mr. Larry Fowler (Teller) in Sheldon and Amy's apartment hiding from his wife (Kathy Bates). Leonard notices parallels in his own marriage, which offends Penny. Leonard apologizes and Penny convinces Mrs. Fowler to give her husband a break. When Mrs. Fowler wants to hang out with her regularly, Penny scares Larry out of the building. Raj instigates a Twitter feud with Neil deGrasse Tyson, but is scared off when confronted over the phone. Neil then calls Bill Nye to scare him, too.
Title reference: Sheldon attempting to schedule his and Amy's conjugal relations.
257. “The Wedding Gift Wormhole”
While opening their wedding gifts, Sheldon and Amy cannot figure out the purpose of the glass shard Leonard and Penny gave them. They decide it must be a clue to a scavenger hunt to the real gift. They eventually end up in the coffee shop where they first met and find a locket in the lost and found that they think must be the real gift. The glass shard was actually a crystal chakra wand that Raj gave as a gift to Howard and Bernadette, who then re-gifted it to Leonard and Penny, who finally passed it on as a joke. Leonard and Penny find it less funny when they are given a coded thank-you note they have to use to unlock their WiFi. After making out with his employee Denise at Sheldon and Amy's wedding reception, Stuart finally asks Denise out on a date; while preparing for the date, he has a spray-tan accident, but she just finds it funny and still goes out with him. Raj is depressed that everyone else has a relationship and asks his father to arrange a marriage for him.
Title reference: Sheldon and Amy's journey to figure out the meaning of the wedding gift.
258. “The Procreation Calculation”
Raj meets with the woman his father set up for him, Anu. Her commanding personality and practical approach to marriage startle Raj, but he agrees to go ahead with it. Howard criticizes him, then apologizes; he just never expected Raj to give up on romance. Raj admits this to Anu, so she proposes to him and he says yes. Raj also sends out a relationship questionnaire to Leonard and Penny, which soon reveals that Penny does not think she ever wants kids, upsetting Leonard, who would like to have kids someday; their friends selfishly badger them on the issue. After telling her father Wyatt, who is also upset, Leonard tells Penny that he will be okay with it, as he never thought he would have her in his life. To get his mind off of it, Penny rents Leonard a Batmobile to drive in and have fun with for the day. Meanwhile, Stuart starts bringing home Denise at night, which makes Howard and Bernadette very uncomfortable. When they also try to make time for themselves, they wake up their kids.
Title reference: Leonard and Penny trying to decide if they want to have children.
259. “The Tam Turbulence”
Sheldon's childhood friend from Texas, Tam, is visiting the university with his son. Sheldon does not want to see him and the others wonder why Sheldon has never mentioned Tam. Tam is unaware Sheldon is angry with him, thinking they just naturally drifted apart. Sheldon's brother George does not know the reason either. Sheldon eventually reveals Tam promised he would move to California with Sheldon, but then got a girlfriend and stayed with her, leaving Sheldon feeling abandoned. Tam and Sheldon make up and Sheldon has Leonard take Tam to the airport. Meanwhile, Penny and Bernadette want to get to know Anu, impressed by her connections in the hotel industry. They tell her embarrassing things about Raj and wonder if they can go out with her again after Raj confronts them.
Title reference: The anxiety caused by Tam's reappearance in Sheldon's life after 20 years of separation.
260. “The Planetarium Collision”
Sheldon is annoyed that Amy does not have time to work on the super-asymmetry project with him, so he talks President Siebert into getting her removed from her own project at the university. Amy is angry at both of them, as she wants to still have her own identity outside the marriage. When confronted by Amy, Siebert apologizes to her, but states that it will be difficult for the university to give her her project back. After talking with Arthur Jeffries in a dream, Sheldon apologizes to Amy and both of them talk about their fears regarding their marriage. Meanwhile, Raj does not want to have Howard join him in his show at the planetarium, thinking he will just use his astronaut status to make it about himself. Raj eventually lets him join in and Raj and Howard spend the whole time complimenting each other, surprising Bernadette, Leonard, and Penny.
Title reference: Howard colliding with Raj's job at the planetarium.
261. “The Imitation Perturbation”
Howard dresses as Sheldon for Halloween at work, hurting Sheldon's feelings, and refuses to apologize for it. Bernadette reveals to Amy that she made Howard's costume in retaliation for Sheldon ridiculing Howard's engineering and insulting Halley by comparing her appearance to Winston Churchill. Appalled at this, Sheldon and Amy dress as Howard and Bernadette at Penny and Leonard's party, angering Bernadette. Sheldon and Bernadette later bond over their painful childhood memories. Leonard is upset that Penny does not seem to remember that their first kiss was on Halloween in 2007. Penny later admits she does remember, but does not like to think of their first kiss as an unromantic drunken hookup. She likes to imagine their first kiss was one they shared on Leonard's 28th birthday, which pleases him.
Title reference: Howard dressing as Sheldon for Halloween and, in response, Sheldon and Amy dressed up as Howard and Bernadette.
262. “The Grant Allocation Derivation”
President Siebert charges Leonard with distributing some extra university funds in the form of a grant. Everyone begins sucking up to Leonard. Penny is impressed by Leonard's decisiveness, but unimpressed when he cannot decide between Raj, Kripke, and Dr. Lee (Maribeth Monroe), an ornithologist who works with crows. Leonard, realizing that people will be angry with him no matter who he gives the funds to, eventually awards the money to himself for a high-powered laser. Meanwhile, a stressed out Bernadette starts hiding in Halley's playhouse after work so she can have time to herself. She is eventually joined by Penny and Amy. Howard reveals to Raj that he actually knows that Bernadette has been hiding out, but is keeping quiet about it so she can have her privacy and so he can use it to his advantage.
Title reference: Leonard choosing a grant recipient.
263. “The Consummation Deviation”
Anu wants to have sex with Raj, but he gets so nervous in the lead-up that his selective mutism returns. Confessing to her, she is very understanding, revealing an unusual secret of her own. The next morning, he is able to have sex with her in the shower. Sheldon attempts to bond with his father-in-law, but Larry is more impressed with Howard's magic tricks, causing a jealous Sheldon to spend time with Mrs. Fowler. They bond after finding out Amy has been using Sheldon as an excuse to avoid her mother, though he does gently advise her to forgive her daughter like he would his wife. A remorseful Amy invites the Fowlers over for dinner, where Sheldon and Mrs. Fowler continue to bond over Larry's ineptitude with magic.
Title reference: Raj unable to sleep with Anu.
264. “The Citation Negation”
Sheldon and Amy recruit Leonard to research and write citations for their paper on super-asymmetry. While working in the campus library, Leonard and Raj discover a Russian paper that asserts that super-asymmetry has no merit. Reluctantly, Leonard shares the news with Sheldon and Amy, who fall into a depressive state and do not leave their apartment. Meanwhile, Bernadette asks Denise to teach her how to play Fortnite: Battle Royale so that she can beat Howard. Despite losing to Howard in a rematch after all of her training, Bernadette revels in beating a disinterested Penny.
Title reference: The Russian paper that disproves Sheldon and Amy's theory.
Note: The vanity card at the end of the episode paid tribute to Stan Lee, who died on November 12, 2018.
265. “The VCR Illumination”
Sheldon is still despondent over the disproving of his and Amy's theory on asymmetry. Leonard brings out a VHS tape of a pep talk that Sheldon recorded as a boy, but it turns out that his father had recorded a long-ago football game over it. Sheldon, however, is buoyed by a halftime pep talk his father gave the team, realizing he and his father had more in common than he previously thought. This causes Amy to view asymmetry and symmetry in another manner and they decide their theory may not be dead after all. Bernadette finds an old tape of Howard preparing to audition for The Magic Castle. She insists he fulfill his dream and audition with her as a coach, drawing on her beauty pageant experience. Howard eventually decides to audition his own way and promptly botches his chances by accidentally destroying a judge's Rolex.
Title reference: Old VHS tapes surfacing from Sheldon's and Howard's pasts.
Note: This episode marks the first appearance of Iain Armitage as Young Sheldon, Lance Barber as George Cooper Sr and Montana Jordan as George Cooper Jr on the show.
266. “The Paintball Scattering”
Sheldon and Amy's paper is a huge success, but Sheldon is upset when President Siebert does not allow him to do interviews with Amy, who gets all the attention. Denise asks Stuart to move in with her, but he panics and flees. Raj sets up a doorbell camera app for Anu, but sees her greet her ex-boyfriend. At a paintball match, all the feuding couples argue, with Raj saying he cannot trust Anu since he does not even know her, throwing the wedding into question. Stuart makes up with Denise by giving her a key to the Wolowitz house. Sheldon tries to do one interview with Amy, but leaves when he is asked about the Russian scientists who had earlier disproved their theory.
Title reference: The paintball match between everyone, which exposes the problems between the couples.
267. “The Propagation Proposition”
Penny runs into her ex-boyfriend Zack, who has gotten rich from selling his company and is now married to a similarly dim-witted woman named Marissa. He invites Leonard and Penny for dinner on their boat. Zack reveals he is infertile and he and Marissa ask Leonard to donate his sperm so they can have a baby. Leonard is flattered, but Penny finds it creepy. Leonard says that since Penny decided she did not want to have children, he should be allowed to help another couple with this issue. Sheldon advises him to think about the emotional toll this could have on him. Leonard says he will not do it if Penny objects; Penny says she will support whatever decision Leonard makes. Meanwhile, Raj tries to get Anu back, but she points out he just wanted to be married like his friends. Raj points out that Anu is similarly looking for a quick marriage. He admits to Anu that he really likes her and they decide to start their relationship as just dating.
Title reference: Zack and Marissa asking Leonard to father their child.
268. “The Confirmation Polarization”
Two physicists from Chicago, Dr. Kevin Campbell and Dr. Greg Pemberton, accidentally prove Sheldon and Amy's super-asymmetry theory. This puts them on track for a Nobel Prize, but Leonard points out they tend to go to the experimental scientists who prove a concept instead of theorists like Sheldon who come up with it. Meeting with them, they tell Sheldon they are willing to share the Prize, but only three names can be on the submission and they want to cut Amy out. Amy does not want to prevent Sheldon's lifelong dream, but he goes to President Siebert, who agrees to fight for Amy on their behalf. Meanwhile, Bernadette's drug has been approved and she wants to promote Penny to lead the marketing team. Penny resists, knowing Bernadette's attitude at work and concerned by her own inexperience in taking responsibility, but Bernadette uses reverse-psychology to get Penny to take the job. Penny mirrors Bernadette's commanding style to get the other employees in line, impressing Bernadette.
Title reference: Sheldon and Amy's reaction to their theory being proven, but then their reaction to Amy possibly being cut out.
269. “The Meteorite Manifestation”
Howard and Bernadette's new neighbor Andy begins using motion sensored floodlights mounted on his balcony, which encroaches on their rear deck and hot tub. Investigating whether the lights comply with city code, they enlist Sheldon to help them with the paperwork, but Sheldon finds out Howard and Bernadette's own deck is also not code-compliant. He considers turning them in, but ultimately chooses friendship over the rules. He does report Andy, though, for violating property lines, allowing Howard and Bernadette to enjoy their deck again. Meanwhile, Bert wants to cut into a meteorite with Raj's help, rejecting Leonard's idea to use his laser to do so. Leonard gets the flu and dreams that he opens the meteorite with his laser, becomes possessed by an alien parasite and eats Bert, Raj, and Penny. He later apologizes to Raj and Bert, admitting he was jealous. The possibility of the meteorite unleashing a plague scares Stuart and Denise, who use it as foreplay for procreation, Stuart closing the store on Sheldon when he tries to browse.
Title reference: Leonard's jealousy and nightmares of opening the meteorite and eating his friends.
270. “The Donation Oscillation”
Leonard tells Zack and Marissa he will father their child, but Penny tries to seduce him, despite knowing he has to be abstinent for a few days. Her visiting father, Wyatt, points out her actions suggest she is more conflicted over having no kids than she lets on, which she admits. Wyatt says he will support her no matter what. Meanwhile, Sheldon and Amy warn Leonard about Penny's reservations and that he will not be allowed to raise a child that is not his. Leonard decides not to go through with it; he tells Zack to ask Sheldon be the donor, but Amy forbids it. Meanwhile, Howard turns Raj's cancelled bachelor party into a couples' trip in a zero-gravity aircraft, though he is convinced that Bernadette would hate it. Bernadette tries to get out of it, so Howard sits out, forcing Bernadette to go through with it just to prove him wrong, though she does not enjoy it.
Title reference: Leonard decides to donate his sperm, but then chooses not to do it.
271. “The D&D Vortex”
Wil Wheaton brings William Shatner on his Professor Proton show to meet Sheldon, who gets so excited that he vomits on Shatner. Going to Wil to apologize, he finds Wil hosts a Dungeons & Dragons group with his celebrity friends, including Shatner. Finding out Stuart is in the group and never told them, the guys make Stuart panic and quit. Wil secretly invites Leonard, who discovers that the group (besides Shatner) also includes Kevin Smith, Joe Manganiello, and Kareem Abdul-Jabbar. Leonard tells Penny, who tells Amy and Bernadette, all three women having a crush on Manganiello. Because of that indiscretion, Wil kicks out Leonard and admonishes the guys for using him for his connections, saying that one of the worst things about being a celebrity is not knowing whether someone will like him for himself. To apologize, the guys invite Wil to play D&D with them at Leonard’s apartment, but Wil, secretly in the middle of a game with Penny, Amy, Bernadette, and the group, politely turns them down before allowing the girls to send them a photo of the event as payback.
Title reference: Wil Wheaton's Dungeons & Dragons group.
272. “The Conference Valuation”
Penny and Bernadette attend a pharmaceuticals conference, where Bernadette's business rival Danny tries to recruit Penny. Bernadette is offended that Penny is considering the offer. At the meeting with Danny, Bernadette steps in to say Penny is the best saleswoman she knows and Penny agrees to keep working for Bernadette. Meanwhile, the rest of the gang does simple behavioral experiments on the Wolowitz children using a book Sheldon found. Leonard is shocked that his childhood was filled with these experiments; although his mother remembers that time with him fondly, she admits the experiment with him is not over. Raj figures Amy planted the book to get Sheldon to like babies, though Sheldon later states he would be open to having kids.
Title reference: Penny being valued as a saleswoman at the pharmaceutical conference.
273. “The Laureate Accumulation”
Campbell and Pemberton start a publicity tour for their Nobel campaign, including appearing on The Ellen DeGeneres Show. Caltech organizes a reception for Amy and Sheldon and reaches out to previous winners, including George Smoot, Kip Thorne, and Frances H. Arnold. Finding that Sheldon has offended most of them in the past, Amy and Sheldon try to get their good graces by sending them baked cookies which they all reject. Leonard and Penny convince them to show up to the reception, but Pemberton and Campbell crash the party. Leonard holds Sheldon back, only for Amy to verbally snap at them. Meanwhile, with Halley scared of the dark, Stuart and Bernadette turn Howard's story from his time in outer space into a children's book, The Frightened Little Astronaut. Howard is embarrassed until Bernadette talks him into helping both children and Stuart's art career by letting it get published.
Title reference: Calling together several Nobel Laureate winners for Sheldon and Amy's event.
274. “The Inspiration Deprivation”
Upon getting called into Human Resources for Amy's outburst, Mrs. Davis tells her and Sheldon they are blowing their chances at the Nobel Prize. Amy would be the fourth woman to win in Physics, pressuring her to be a role model for women everywhere. To calm down, they try a sensory deprivation tank; Sheldon loves it, but it only worsens Amy's mood. Sheldon does not know how to help and ends up holding her while singing "Soft Kitty". A newly confident Amy goes back to Human Resources to be allowed to campaign again and shares a drink with Davis. Meanwhile, Howard buys a scooter to ride with Raj like in the old days. Bernadette finds out and makes him sell it, since it is too dangerous. Bert buys it and ends up meeting a nurse after he dislocates his arm in a wreck.
Title reference: Sheldon and Amy going into sensory deprivation tanks to calm down from the Nobel campaign.
275. “The Decision Reverberation”
When Penny tells Leonard he needs to be more assertive in making decisions for himself, he starts standing up to Sheldon over small things. His confidence makes him demand that the university support his idea for a plasma physics project. He threatens to quit if the university refuses, alarming both Sheldon and Penny, who consider this to be a risky career move. Sheldon is conflicted on whether or not he is being selfish over Leonard's decision, but Amy suggests that the fact that he is worried over Leonard's motivation proves that he does care about him, which he acknowledges. President Siebert refuses the project but, in order not to lose Leonard, gives him co-leadership over a photon entanglement project, leaving Leonard proud of himself and Penny impressed. Meanwhile, Raj shows Anu his lab and suggests one possible answer for something he has seen in space might be alien life. When someone mentions this at his observatory presentation, the scientific community starts mocking him as a conspiracy theorist. Raj points out scientists should consider all possibilities when seeking the truth, though this causes people to think he believes in the Loch Ness Monster.
Title reference: Leonard deciding to be more assertive and threatening to quit if the university does not support his idea.
276. “The Plagiarism Schism”
Kripke offers to get proof that Pemberton plagiarized his thesis, which would destroy his career and his chances at the Nobel Prize. Sheldon and Amy decide not to pursue this; they want to win on their own merits. Leonard secretly obtains the information from Kripke to expose Pemberton. Amy and Sheldon give the evidence to Pemberton and Campbell, as they refuse to blackmail them. Having been unaware of this, Campbell is furious that Pemberton's dishonesty could hurt his own career. Campbell then reveals he is sleeping with Pemberton's ex-wife, causing the pair to brawl. Afterwards, Campbell exposes Pemberton, getting Pemberton fired. Amy and Sheldon reject a drunken Campbell's request to join their team. Bernadette tells Howard that another waitress at the Cheesecake Factory was attracted to him back in the day, so she said Howard had hepatitis to scare her off. At first, Howard obsesses over who it was, but he tells Bernadette she is the only one that matters to him.
Title reference: Dr. Pemberton's plagiarism destroying his partnership with Dr. Campbell.
277. “The Maternal Conclusion”
Leonard's mother Beverly visits and he is thrilled when she takes an interest in his work as co-lead for the University's Photon Entanglement Project. However, when he learns that she is only being nice to him for research on a new parenting book, he is furious. He prepares to tell her how she let him down over the years, but instead chooses to accept and forgive her, and forgive himself for holding on to that resentment for so long. Beverley is touched that he forgave her and they share a genuine hug. Meanwhile, Anu gets a job offer in London. Raj prepares to fly out and propose to her, ready to follow her if she accepts. Howard stops Raj at the airport, saying there is a better match out there for him and convincing Raj to return home. Stuart and Denise are bothered by her creepy roommate Mitch, while Bernadette and Howard are tired of Denise constantly staying overnight with Stuart at their house. Stuart and Denise decide to move in together, admitting they love each other while convincing Mitch to move out.
Title reference: Leonard accepting his relationship with his mother for what it is.
278. “The Change Constant”
The episode opens with a short montage of clips from the series' twelve seasons, then segues to Sheldon and Amy, who are up late waiting for a call from the Nobel Committee. Following a prank call from Kripke, they are told they have won the Nobel Prize in Physics for their super-asymmetry work. The sudden attention from the media and the university bothers Sheldon, while Amy is saddened by unflattering pictures of her in the news. Seeing her dispirited, Raj convinces her to get a makeover. She loves her new look, but a rattled Sheldon demands she change it back. He then flees when he sees Penny emerge from the newly repaired elevator. Sheldon and Penny go to the Cheesecake Factory and Penny tells Sheldon that change is the only constant thing in life, so Sheldon finally accepts the changes in his life. On TV, they see Bernadette and Howard claim to be Sheldon and Amy's best friends. Raj and Leonard defend Amy, with Leonard accidentally breaking Sheldon's DNA molecule model in Apartment 4A. In the end, Penny convinces Sheldon to ride in the elevator.
Title reference: Penny pointing out to Sheldon that the only constant in life is change.
279. “The Stockholm Syndrome”
After Sheldon and Leonard spend two months repairing Sheldon's DNA molecule model, everyone prepares to fly to Sweden for the Nobel Prize award ceremony. Howard and Bernadette nervously leave their kids for the first time with Stuart and Denise, while Raj leaves his dog with Bert. Penny has become pregnant, though she and Leonard are keeping it a secret. On the flight, Raj meets Sarah Michelle Gellar. Penny's frequent bathroom trips make Sheldon fear she is sick. Penny reveals her pregnancy to Sheldon but, instead of being excited for her, Sheldon is only selfishly relieved that he will not get sick, and he exposes the pregnancy, offending Leonard. At the hotel, a series of minor incidents with their kids make Howard and Bernadette want to go home. Much to their dismay, Sheldon is still insensitive. Amy furiously tells Sheldon he broke his friends' hearts and that people (sometimes including her) only tolerate him because he does not intentionally do so. Everyone decides to stay for the ceremony and Raj brings Gellar as a plus-one. After they are awarded their medals, Amy encourages girls to pursue science while Sheldon thanks his family and then, discarding the acceptance speech that he wrote as a child, individually acknowledges each of his friends and Amy as his other family who always support him, apologizing to all of them for not being the friend they deserved. In the last scene in the episode and the series, the gang is eating in Apartment 4A (an allusion to the final scene in the opening credits) with Sheldon and Amy wearing their medals as a melancholic acoustic version of the series' theme song's chorus plays.
Title reference: Sheldon thinking Penny is ill on the flight to Stockholm; a reference to Stockholm syndrome.