We no longer support this version of Internet Explorer. Please update your browser for a better experience of All4.com. For more information visit our FAQs

Section navigation

Episode Guides

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 6 Summary

The sixth series of the US comedy about a group of highly intelligent but socially clueless scientists and their savvy neighbour Penny.

  • Episode 1 - The Date Night Variable

    Episode 1 - The Date Night Variable

    Howard gets caught in an argument between his mum and Bernadette while at the International Space Station. Raj is feeling lonely so Sheldon invites him along to his second anniversary date with Amy.

  • Episode 2 - The Decoupling Fluctuation

    Episode 2 - The Decoupling Fluctuation

    Sheldon intervenes when he learns that Penny is thinking about breaking up with Leonard, but he's hampered by his inability to keep a secret. Meanwhile, in space, the astronauts are picking on Howard.

  • Episode 3 - The Higgs Boson Observation

    Episode 3 - The Higgs Boson Observation

    Amy is jealous when Sheldon hires an attractive female assistant named Alex. However, it turns out that Alex is more interested in Leonard, which makes Penny feel threatened.

  • Episode 4 - The Re-entry Minimization

    Episode 4 - The Re-entry Minimization

    Howard is disappointed when he doesn't receive a hero's welcome on his return from space. Will he ever get the recognition he deserves as an astronaut?

  • Episode 5 - The Holographic Excitation

    Episode 5 - The Holographic Excitation

    The gang celebrates Halloween with a fancy dress party at Stuart's comic book shop, but Sheldon and Amy can't agree about which costumes to wear

  • Episode 6 - The Extract Obliteration

    Episode 6 - The Extract Obliteration

    Sheldon is excited when Stephen Hawking (guest starring as himself) agrees to play Words with Friends with him online. But Hawking's not happy when Sheldon starts to dominate the game.

  • Episode 7 - The Habitation Configuration

    Episode 7 - The Habitation Configuration

    Sheldon fails to defend Amy in an argument with Wil Wheaton while filming Fun with Flags. Guest stars Star Trek: The Next Generation actors Wil Wheaton and LeVar Burton.

  • Episode 8 - The 43 Peculiarity

    Episode 8 - The 43 Peculiarity

    The guys notice that Sheldon disappears for 20 minutes right after lunch every day. Filled with curiosity, they attempt to follow him and work out what on earth he's been doing.

  • Episode 9 - The Parking Spot Escalation

    Episode 9 - The Parking Spot Escalation

    When non-driver Sheldon finds out that his unused parking space at the university has been reallocated to Howard, he feels undermined and the two fall out

  • Episode 10 - The Fish Guts Displacement

    Episode 10 - The Fish Guts Displacement

    Sheldon begrudgingly takes care of Amy when she is sick, but she loves the extra attention so much that she is still pretending to be ill long after her recovery is complete

  • Episode 11 - The Santa Simulation

    Episode 11 - The Santa Simulation

    Sheldon reveals painful memories of Christmas past when Leonard persuades him to join in with a seasonal game of Dungeons & Dragons. Raj joins Penny, Bernadette and Amy on a ladies' night out.

  • Episode 12 - The Egg Salad Equivalency

    Episode 12 - The Egg Salad Equivalency

    When Sheldon's assistant Alex starts flirting with Leonard, Sheldon is displeased and decides to have a word with her about it

  • Episode 13 - The Bakersfield Expedition

    Episode 13 - The Bakersfield Expedition

    The guys take a road trip to a comic book convention in Bakersfield and visit a location where several episodes of Star Trek were filmed. But Leonard's car is stolen, leaving them stranded.

  • Episode 14 - The Cooper/Kripke Inversion

    Episode 14 - The Cooper/Kripke Inversion

    Sheldon is forced to work on the same project as his nemesis, Barry Kripke. Howard and Raj spend a fortune on personalised action figures.

  • Episode 15 - The Spoiler Alert Segmentation

    Episode 15 - The Spoiler Alert Segmentation

    Sheldon and Leonard have a row when Sheldon gives away the ending of the Harry Potter book that Leonard is reading

  • Episode 16 - The Tangible Affection Proof

    Episode 16 - The Tangible Affection Proof

    Leonard tries to give Penny the perfect Valentine's Day treat by taking her to a nice restaurant with Howard and Bernadette. Meanwhile, Raj and Stuart throw a singles party at the comic book shop.

  • Episode 17 - The Monster Isolation

    Episode 17 - The Monster Isolation

    After a terrible date with Lucy, who he met at Stuart's singles party, Raj vows never to leave his flat or interact with another woman again. Leonard, Howard and Bernadette try to cheer him up.

  • Episode 18 - The Contractual Obligation Implementation

    Episode 18 - The Contractual Obligation Implementation

    When Leonard, Sheldon and Howard have to volunteer for a university committee, they join one that advances the cause of women in science and arrange to speak to schoolgirls about their careers

  • Episode 19 - The Closet Reconfiguration

    Episode 19 - The Closet Reconfiguration

    When Howard and Bernadette get Sheldon to organise their untidy closet, Sheldon finds an unopened letter from Howard's long-absent father, who abandoned his family years earlier

  • Episode 20 - The Tenure Turbulence

    Episode 20 - The Tenure Turbulence

    When a tenured position becomes available at the university, Leonard, Sheldon, Raj and Kripke are all keen to apply for it

  • Episode 21 - The Closure Alternative

    Episode 21 - The Closure Alternative

    Amy employs a series of exercises to cure Sheldon of his compulsion to complete every task without fail and seek closure for every incident

  • Episode 22 - The Proton Resurgence

    Episode 22 - The Proton Resurgence

    When Leonard and Sheldon find out that Professor Proton, the host of a TV science show they watched as children, can be booked for private parties, they hire him to come and entertain them

  • Episode 23 - The Love Spell Potential

    Episode 23 - The Love Spell Potential

    When the girls' planned trip to Las Vegas falls through, the guys invite them to a Dungeons & Dragons date night, which results in Sheldon and Amy's relationship taking an unexpected turn...

  • Episode 24 - The Bon Voyage Reaction

    Episode 24 - The Bon Voyage Reaction

    Leonard is offered an exciting job opportunity that will keep him out of the country for several months. Meanwhile, Raj pushes the boundaries of his relationship with Lucy.