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Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...

About the Show

Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...

Series 4 Summary

In this series Sheldon goes on his first ever date, Wolowitz finds a new use for a robotic arm, the gang meet Apple co-founder Steve Wozniak and Sheldon calculates how many relationships Penny has had.

  • The Big Bang Theory

    Episode 1 - The Robotic Manipulation

    In the opening episode, Penny tags along to Sheldon's first ever date with a woman he's been texting for months.

    Meanwhile, Wolowitz finds a new use for a robotic arm.

  • The Big Bang Theory

    Episode 2 - The Cruciferous Vegetable Amplification

    Sheldon realises he won't live long enough to download his consciousness into a robot body, so he tries to extend his lifespan

  • The Big Bang Theory - the gang stand by their flat door

    Episode 3 - The Zazzy Substitution

    The guys are concerned when a heartbroken Sheldon starts bulk-buying cats after he breaks up with Amy. Leonard realises he must get Sheldon's mother to visit.

  • The Big Bang Theory gang

    Episode 4 - The Hot Troll Deviation

    An embarrassing secret of Wolowitz's comes to light as he tries to win back his ex-girlfriend, Bernadette.

    Meanwhile, Sheldon and Raj engage in a battle of wills.

  • Sheldon's girlfriend in The Big Bang Theory

    Episode 5 - The Desperation Emanation

    Leonard realises that he's the only one of the gang without a girlfriend, while Sheldon wants to get rid of his when she hatches a plan for him to meet her mother.

  • Sheldon in The Big Bang Theory series four

    Episode 6 - The Irish Pub Formulation

    A visit from Raj's sister Priya creates tension among the guys - especially when Leonard coaxes Sheldon into hiding his romantic past with Priya from the rest of the gang.

  • The gang in the shop in The Big Bang Theory

    Episode 7 - The Apology Insufficiency

    Leonard believes his problem with women stems from a lack of confidence, and vows to be more self-assured around attractive women.

    Meanwhile, Wolowitz has a call from the FBI.

  • The gang sit in the living room in Big Bang Theory

    Episode 8 - The 21-Second Excitation

    Sheldon's movie-going plans are scuppered by his nemesis Wil Wheaton. Penny and Bernadette invite Amy to her first slumber party.

  • leonard in The Big Bang Theory

    Episode 9 - The Boyfriend Complexity

    When Penny's father comes to visit, Leonard discovers that her parents still think that he and Penny are a couple

  • The Big Bang Theory: Sheldon

    Episode 10 - The Alien Parasite Hypothesis

    Amy discovers that she has feelings for Penny's ex-boyfriend Zack.

    Meanwhile, Koothrappali and Wolowitz try to prove who would be the better superhero.

  • The Big Bang Theory: Penny

    Episode 11 - The Justice League Recombination

    The guys warm to Penny's new boyfriend Zack and find a way to bond with him.

  • The Big Bang Theory: The cast from series four

    Episode 12 - The Bus Pants Utilization

    Leonard's idea for a smartphone application derails his friendship with Sheldon as they fight for control of the project

  • Big Bang Theory: The gang in their living room

    Episode 13 - The Love Car Displacement

    Howard feels threatened when Bernadette runs into her hulk of an ex-boyfriend at a science conference

  • The Big Theory: The gang on their sofa

    Episode 14 - The Thespian Catalyst

    Sheldon lectures at the university but worries that the students don't seem to like him. Raj fantasises about his best friend's girlfriend.

  • The Big Bang Theory: Sheldon sits down to dinner

    Episode 15 - The Benefactor Factor

    A wealthy benefactor at the university makes Leonard ponder just how far he's willing to go in the name of science.

  • The Big Bang Theory: Rajesh

    Episode 16 - The Cohabitation Formulation

    Wolowitz is torn between taking things to the next level with Bernadette, and pleasing his mother.

    Leonard rekindles his relationship with Raj's sister, Priya.

  • Big Bang Theory: Sheldon

    Episode 17 - The Toast Derivation

    Sheldon gets a new group of friends when the gang start hanging out at Raj's more often and he realises that it's actually Leonard who is the centre of their social group and not him.

  • The Big Bang Theory: Leonard and Penny

    Episode 18 - The Prestidigitation Approximation

    Leonard must choose between his new girlfriend Priya, and his friendship with Penny. Meanwhile, Howard drives Sheldon crazy with a magic trick.

  • The Big Bang Theory: Leonard and Sheldon

    Episode 19 - The Zarnecki Incursion

    When someone hacks Sheldon's online gaming account, the guys go on a quest to find the culprit.

  • Big Bang Theory: Sheldon

    Episode 20 - The Herb Garden Germination

    Sheldon and Amy experiment on their friends by spreading gossip, while Howard takes a big step in his relationship with Bernadette.

  • The Big Theory

    Episode 21 - The Agreement Dissection

    Priya uses her legal nous to dissect the roommate agreement and put Sheldon in his place. Meanwhile, the girls take Sheldon dancing.

  • The Big Bang Theory

    Episode 22 - The Wildebeest Implementation

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

  • The Big Bang Theory: Sheldon and Leonard

    Episode 23 - The Engagement Reaction

    Howard finally tells him mum that he's engaged to Bernadette. Unfortunately, the news lands his mum in hospital.

  • Big Bang Theory: Leonard and Sheldon

    Episode 24 - The Roomate Transmogrification

    In the series four finale, Raj moves in with Sheldon after overhearing Leonard and Priya's Star Trek bedroom fantasy

The Big Bang Theory synopsis

Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...

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3 Episodes

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