The Big Bang Theory (season 5)

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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!"

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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".