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The Big Bang Theory Season 4

The Robotic Manipulation
Episode 1
Air Date: Sep 23, 2010

The Robotic Manipulation

Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.

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The Cruciferous Vegetable Amplification
Episode 2
Air Date: Sep 30, 2010

The Cruciferous Vegetable Amplification

Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.

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The Zazzy Substitution
Episode 3
Air Date: Oct 7, 2010

The Zazzy Substitution

The guys are concerned as Sheldon searches for an alternative to human companionship.

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The Hot Troll Deviation
Episode 4
Air Date: Oct 14, 2010

The Hot Troll Deviation

An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.

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The Desperation Emanation
Episode 5
Air Date: Oct 21, 2010

The Desperation Emanation

Leonard realizes he's the only one without a girlfriend, while Sheldon wants to get rid of his.

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The Irish Pub Formulation
Episode 6
Air Date: Oct 28, 2010

The Irish Pub Formulation

Leonard keeps an affair a secret from Sheldon, Howard and Raj.

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The Apology Insufficiency
Episode 7
Air Date: Nov 4, 2010

The Apology Insufficiency

Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.

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The 21-Second Excitation
Episode 8
Air Date: Nov 11, 2010

The 21-Second Excitation

While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.

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The Boyfriend Complexity
Episode 9
Air Date: Nov 18, 2010

The Boyfriend Complexity

Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.

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The Alien Parasite Hypothesis
Episode 10
Air Date: Dec 9, 2010

The Alien Parasite Hypothesis

Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.

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The Justice League Recombination
Episode 11
Air Date: Dec 16, 2010

The Justice League Recombination

The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.

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The Bus Pants Utilization
Episode 12
Air Date: Jan 6, 2011

The Bus Pants Utilization

Leonard's idea for a smartphone app derails his friendship with Sheldon.

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The Love Car Displacement
Episode 13
Air Date: Jan 20, 2011

The Love Car Displacement

Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.

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The Thespian Catalyst
Episode 14
Air Date: Feb 3, 2011

The Thespian Catalyst

Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.

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The Benefactor Factor
Episode 15
Air Date: Feb 10, 2011

The Benefactor Factor

A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.

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The Cohabitation Formulation
Episode 16
Air Date: Feb 17, 2011

The Cohabitation Formulation

As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.

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The Toast Derivation
Episode 17
Air Date: Feb 24, 2011

The Toast Derivation

Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.

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The Prestidigitation Approximation
Episode 18
Air Date: Mar 10, 2011

The Prestidigitation Approximation

Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with…

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The Zarnecki Incursion
Episode 19
Air Date: Mar 31, 2011

The Zarnecki Incursion

Sheldon's World of Warcraft online game account is hacked and he is determined to find out who did it. Also Penny shares some girl talk with…

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The Herb Garden Germination
Episode 20
Air Date: Apr 7, 2011

The Herb Garden Germination

Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even …

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The Agreement Dissection
Episode 21
Air Date: Apr 28, 2011

The Agreement Dissection

When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, …

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The Wildebeest Implementation
Episode 22
Air Date: May 5, 2011

The Wildebeest Implementation

Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.

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The Engagement Reaction
Episode 23
Air Date: May 12, 2011

The Engagement Reaction

When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.

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The Roommate Transmogrification
Episode 24
Air Date: May 19, 2011

The Roommate Transmogrification

When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.

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