List of The Big Bang Theory episodes (season 4)

The episode starts with the five main characters having dinner and then oscillates between two plots. In one plot, Howard demonstrates during dinner the capabilities of a robotic arm, that he "borrowed" from the Jet Propulsion Laboratory by showing off how the robotic arm can serve dinner. He later uses the robotic arm to give himself a massage. Since the arm feels so real, it gives him the idea to use the robotic arm to masturbate. He then gets his genitals stuck in the arm and calls Leonard to ask for help. When Leonard and Raj show up in his bedroom he lies to them that he accidentally slipped over the arm. Leonard and Raj do not believe him, and start to mock him. They then take Howard to the emergency room with his genitals attached to the robotic arm, and the arm attached to the computer which controls it. Going against Howard's fears that turning off the computer would make his situation worse, the attending nurse (Vernee Watson) turns off the computer, and Howard is freed.

The second plot starts during the dinner at the beginning of the show, when Penny comes to know of Sheldon's new friend, Amy Farrah Fowler (Mayim Bialik), when Sheldon reads out loud a text message that he received from Amy. To everyone's surprise, Sheldon announces his plans to conceive a progeny with Amy via in vitro fertilization with Penny being the surrogate mother. Penny suggests that before going through such a plan, he 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 to his date. During the drive Penny finds out that it is Sheldon's first date, so she offers suggestions which Sheldon rebuffs. In a later scene Amy joins them in the car, and Penny's attempts at conversation fail. Later at the restaurant, Sheldon calculates the number of dates that Penny might have had in her life by extrapolating the data he collected over the past three years. He comes with a number: 193. He then proceeds to calculate the number of cases that might have resulted in sexual encounters and gets the number 31. To Penny's vexation, Amy asks her whether she ever felt like a "slut".

The episode ends with Sheldon dropping his plans to have an in vitro fertilization with Amy because Penny threatens to tell Sheldon's religious mother, and Howard getting "stuck" again.

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 to eat cruciferous vegetables and starts to exercise in hopes of extending his life expectancy. Since the diet of brussels sprout gives him a bad case of flatulence, and he tumbles on the stairs going down for a jog, Sheldon decides on an alternate plan to extend his life expectancy. Sheldon builds a robotic replication of himself which he calls a "Mobile Virtual Presence Device" (the telepresence robot by Willow Garage^[4] ) 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 MVPD has a monitor showing Sheldon's face in real time (or any other image that Sheldon wants to display at that moment), speakers so Sheldon's voice can be heard, and a microphone and camera to allow Sheldon to "see" and "hear" what is happening at the MVPD's location while he stays in the "secure, undisclosed location". Sheldon can then react to the situation as if he was present (to the point of enforcing the rule that nobody sits on "his spot" on the sofa). The monitor sits on top of a fixture covered with the exact same clothing that Sheldon is wearing that day. The MVPD has wheels which give it mobility and is equipped with an override switch so if anybody turns the MVPD off (because they don't want to hear Sheldon talking), Sheldon can override and turn the MVPD back on.

The guys dismiss the MVPD as a stunt (Penny calls it "Shelbot") and try to convince Sheldon to drop the idea, but Sheldon persists and proceeds to cite a section of the roommate agreement requiring Leonard to assist him (by providing him transportation) "in the event one of [the roommates] becomes a robot". Leonard therefore takes the MVPD to work, and later to Penny's restaurant for dinner. At the restaurant, Sheldon, via his MVPD, spots Steve Wozniak at a nearby table so he sends the MVPD so that he can talk to Wozniak. He tells Wozniak that he has a vintage Apple II to which Wozniak says that if he had the Apple II there he would have signed it. Sheldon then takes his Apple II and rushes out of the apartment, but trips and falls down the stairs as he rushes to the restaurant, breaking the Apple II.

Sheldon and Amy Farrah Fowler 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 would be the answer to a question about "an alternate world that differs from ours in one key aspect" (Leonard flunks miserably when he attempts to play this game). Bringing Amy into the group is a source of consternation, as the guys can barely handle Sheldon by himself, let alone with Amy, his female equivalent. At one lunch, Amy belittles Sheldon's occupation as a theoretical physicist relative to, in her opinion, her more superior occupation of neurobiologist. This leads Sheldon to propose for the "relationship [with Amy to] terminate immediately", much to the delight of the other guys. As a result of the breakup, Sheldon becomes more peculiar than his normal self, and adopts a cat as a substitute for Amy. This one cat quickly grows into a collection of 25 cats. This worries Leonard, who calls Sheldon's mother (Laurie Metcalf) to come for help. When she arrives, Mrs. Cooper is shocked, as she never expected this, so she calls Amy to come and help. Amy agrees out of scientific curiosity, because since Mrs. Cooper told her that Sheldon is losing his mind over Amy, as a neurobiologist, Amy wants to see how someone can lose their mind. As Amy, Sheldon, Leonard, and Sheldon's mother sit around the living room, Sheldon's mother employs a technique of reverse psychology which Leonard instantly picks up on, but Sheldon is completely oblivious to. She tells Sheldon that it was a good thing he and Amy broke up because they are completely incompatible. Sheldon is instantly offended, so to prove his mother wrong, he offers Amy to reconcile, which she agrees after a negotiation on the amount of responsibility Sheldon has to accept for the break up (Amy offered 80%, Sheldon countered with 40%, settling at 65%). The episode ends with Sheldon and Amy giving away $20 to anybody willing to adopt a cat.

When the guys run into Howard's ex at the Cheesecake Factory, he ends up confronting his lingering feelings for her. He seeks help from Penny, who agrees on the condition that Howard reveal the reason behind his breakup. He confesses that Bernadette caught him engaging in cybersex with a fellow World of Warcraft player, later revealed to be a male colleague at the university. Howard and Bernadette discuss their relationship at the restaurant and make amends, deciding to give it another try. They go out on a date and are last seen making out in her car.

Meanwhile, Sheldon and Raj are arguing about whether or not Raj can have a desk. Sheldon cites budgetary reasons and Raj offers to buy his own desk, provided he can put it in Sheldon's office. Sheldon arrives at the office later to find Raj sitting behind a large and ornate desk. Sheldon demands it be removed and Raj refuses, leading to an escalating battle of annoyances. Eventually, Sheldon tries to "smoke" Raj out with hydrogen sulfide gas. Raj decides to counter by lighting aromatherapy candles, igniting the gas. Raj and his recently acquired parakeet vacate the office in a cloud of smoke with Raj stating "This is not over."

Katee Sackhoff and George Takei guest star as Howard's love gurus.^[7]

Title reference: Howard's online affair in World of Warcraft with a female troll.

When Amy Farrah Fowler asks Sheldon to meet her mother, it worries Sheldon. He still adamantly says that Amy is his friend but not his "girlfriend". When Leonard reveals to him that he can't actually say that anymore, it freaks him out and he tries to "break up" with her. When she tells him it is only to please her mother, and that she doesn't actually want to be his girlfriend, he is happy again. He goes along with her idea and tells Amy's mother via webcam that he is having regular sex with her daughter, which freaks her out just like Amy wanted it to. Sheldon then asks Amy if they actually want to have sex, and then says "Bazinga!" She leaves and he goes to bed.

While Sheldon has his problems, Leonard has his. Frustrated by the fact that Howard has Bernadette, Sheldon has Amy, Stuart has a woman he met at Comic-Con, and Raj has a girlfriend who is deaf (thus his selective mutism around women is inconsequential), Leonard invokes the "Girlfriend Pact" with Howard, last mentioned in The Creepy Candy Coating Corollary from Season 3. Howard gets Bernadette to set Leonard up on a date with one of her friends, a woman named Joy who is into fitness and martial arts. This date ends up being one of the worst of his life, however, Leonard agrees to another date with Joy because he may get to have sex with her.

Note: Kaley Cuoco is absent from this episode due to a broken leg sustained during a real life horseback riding accident. This is the first time that a regular cast member has not appeared in an episode.

Raj's sister Priya (Aarti Mann) visits and inadvertently causes trouble for the friends. She and Leonard apparently have a history, despite Leonard's pinky swear with Howard that they would not interact with her in deference to Raj. They hook up, but are discovered by Sheldon, who tries to devise an elaborate, flawless lie to cover it up. Leonard cannot persist in the deception and reveals the assignation. The guys then confess to all of the deceptions they have perpetrated on each other, including Sheldon's experiment of feeding moth parts to Leonard. The episode ends with Sheldon preparing snow cones made with mango caterpillar, which grosses Leonard out.

Note: Kaley Cuoco was absent from this episode due to a broken leg sustained during a real life horseback riding accident.

Howard is trying to get top-level security clearance, and in order to clear him, the FBI sends an agent to interview his friends about his past and any secrets he may have. However, Sheldon accidentally talks about when Howard got a Mars rover stuck in a ditch in The Lizard-Spock Expansion from season 2, and Howard is subsequently denied clearance off-screen. After unsuccessfully attempting to retract his statement, Sheldon apologizes to Howard, but Howard does not accept his apology. He then goes to a bar and asks Penny for a drink, but the whiskey is too bitter, and he spits it back into the shot glass each time he tries to drink it. Shortly thereafter, Sheldon gives Howard his spot on the couch, resulting in Howard accepting his apology. The episode ends with Sheldon asking for his spot back after only 94 seconds, and Leonard giving Penny money for losing a bet.

Eliza Dushku guest-stars as Angela (FBI Agent). Neil deGrasse Tyson makes a cameo appearance as himself.

Note: Because of her broken leg, Kaley Cuoco is shown working as a bartender, instead of in her normal job as a waitress at The Cheesecake Factory.

Sheldon, Leonard, Raj, and Howard excitedly plan to attend a screening of Raiders of the Lost Ark that includes 21 seconds of never-before-seen footage. However, they delay reaching the theater, resulting in a lot of complaining from Sheldon. After a short time, Wil Wheaton arrives for the show. Much to Sheldon's dismay, Wheaton is ushered into the theater ahead of everyone, and the four are later denied access to the theater because of this. Just as they start to leave, Sheldon discovers a side door and rushes in. Leonard, Howard, and Raj follow him in and find Sheldon holding the film cans for the screening, which he stole from the unguarded projection room. After being discovered by Wheaton, Sheldon taunts him and subsequently leads his friends, Wheaton, and a mob of angry Raiders fans on a chase through the city streets.

Meanwhile, Penny and Bernadette have a "girls' night" in Penny's apartment. Amy, who was originally planning on attending the movie with the guys, decides to join Penny and Bernadette claiming "I'm a girl". As Amy has never been to a "sleepover" before, she searches Wikipedia^[12] to determine sleepover customs, which Penny and Bernadette reluctantly go along with. During a game of Truth or Dare, Bernadette and Amy catch Penny off-guard when they ask her personal questions regarding her breakup with Leonard; eventually, Penny storms into her bedroom. In the final scene, Amy discovers that lesbian experimentation is allegedly common in sleepovers, and enters Penny's bedroom. The scene ends with Bernadette sitting on the couch listening to Penny's horrified reaction, and musing that eating raw cookie dough would have been a better activity.

Title reference: Sheldon, Leonard, Raj, and Howard are excited to see a print of Raiders of the Lost Ark, which includes 21 seconds of never-before-released footage.

Leonard is flattered when he shows up at Penny's door and gets a kiss from Penny. Later, Penny informs him that her critical father Wyatt (Keith Carradine) is visiting, and she asks him to pretend that they're back together because he's the only boyfriend she's ever had that her father likes. Leonard is initially wary of the idea, but gleefully plays along to get Penny to confess (he also calls her on her hypocrisy at being mad at him for going along with her stupid, flawed plan), which she finally does while her father and Leonard are Wii fishing. Penny's father confronts her about the hoax; then, after Penny leaves the room, he begs Leonard to get back together with Penny because he wants grandchildren and knows Penny's next boyfriend(s) won't provide them. Leonard plays along as Wyatt pretends to angrily throw him out of the apartment.

Meanwhile, Howard and Raj spend the night looking through a space telescope. Raj gets mad at Howard when he discovers that Howard invited his girlfriend Bernadette until he discovers that Bernadette brought wine. When an intoxicated Raj complains that "no girl ever wants to kiss him," Bernadette shows sympathy for him and he attempts to kiss her. Howard attempts to stop Raj but they end up sharing a lengthy kiss. The following morning, when asked by Leonard and Sheldon, both act awkward around each other.

Note: Penny's father's name is changed from Season 2's "The Maternal Capacitance" when Penny referred to him as "Bob," however in this episode his name is Wyatt.