The Big Bang Theory
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 5 Summary
This series brings the sound of wedding bells and more is discovered about the complicated lives of Sheldon, Leonard and their socially dysfunctional friends.
Episode 1 - The Skank Reflex Analysis
Penny worries that she's screwed things up with her friends after her night with Raj. Meanwhile Sheldon takes command of the paintball team.
Episode 2 - The Infestation Hypothesis
A battle of wills between Sheldon and Penny leaves Amy in the middle. Leonard tries to spice up his long-distance relationship with Priya.
Episode 3 - The Pulled Groin Extrapolation
Leonard goes as Amy's date to a colleague's wedding. Howard tries to convince Bernadette to live with his mum after they get married.
Episode 4 - The Wiggly Finger Catalyst
Raj is upset that he's the only one of the four guys not in a relationship, so Penny sets out to find him the perfect date.
Episode 5 - The Russian Rocket Reaction
Sheldon's old nemesis Wil Wheaton returns and invites everyone to a housewarming party. Sheldon threatens to 'de-friend' Leonard if he goes.
Episode 6 - The Rhinitis Revelation
Sheldon's mum visits and soon becomes a firm favourite with his friends, much to Sheldon's annoyance.
Episode 7 - The Good Guy Fluctuation
Leonard questions his feelings for Priya when he kisses a girl he meets in the comic book store.
Episode 8 - The Isolation Permutation
Amy is heartbroken when she finds out that Penny and Bernadette have been shopping for bridesmaids dresses without her.
Episode 9 - The Ornithophobia Diffusion
Leonard and Penny attempt to hang out without anybody else around, while Sheldon faces his fear of birds.
Episode 10 - The Flaming Spittoon Acquisition
Stuart from the comic book shop asks Amy out on a date. In jealousy, Sheldon asks her to be his girlfriend.
Episode 11 - The Speckerman Recurrence
Leonard confronts the man who bullied him in high school, while Penny realises she did her fair share of tormenting in the past.
Episode 12 - The Shiny Trinket Maneuver
When Sheldon is dismissive of Amy's career progress, Penny, Raj and Leonard try to make him realise that it's beneficial to a relationship to pretend to care about things, even if you aren't really that interested.
Howard notices that Bernadette can't stand being around children when the two of them perform a magic show at his nephew's birthday party.
Episode 13 - The Recombination Hypothesis
In the 100th episode of the US sitcom, Leonard decides to ask Penny out on a date, and they both agree to give their relationship another chance.
They argue over dinner and remember why things didn't work out between them in the first place, but end up sleeping together anyway.
Later they agree to continue seeing each other secretly, on the condition that they act like friends when everyone else is around, just to make sure that the relationship works this time.
Episode 14 - The Beta Test Initiation
Leonard and Penny decide to put their relationship through a 'beta test', allowing them to report the problems they have with each other as 'bugs'.
However, when lengthy lists of relationship bugs are exchanged, Leonard takes it to heart and decides to treat Penny to a 'real date' at a firing range.
Episode 15 - The Friendship Contraction
After Sheldon keeps Leonard awake all night, Leonard decides that he needs a break from Sheldon's thankless demands and the Roommate Agreement is formally broken, ending the friendship between them.
While preparing to go on a flight to the International Space Station, Howard enlists Raj's help to make sure that he gets a cool astronaut nickname like the rest of the crew.
Episode 16 - The Vacation Solution
Sheldon is forced to use up his two weeks of holiday time from work, so he spends his fortnight off helping Amy in her biology lab.
He complains that the tasks she gives him to do are menial and boring, but when she finally relents and asks him to dissect a brain, he cuts his thumb open and passes out.
When Bernadette asks Howard to sign a pre-nuptial agreement before their wedding, Penny grows curious about Leonard's feelings on the subject.
Episode 17 - The Rothman Disintegration
When Sheldon and Kripke argue over who should get Professor Rothman's vacant corner office, Leonard, Raj and Howard devise a contest to settle the issue with the office as the winning prize.
Unfortunately, the contest has a sporting theme, and both Sheldon and Kripke are terrible at sports.
Meanwhile, Amy buys Penny a painting to celebrate their friendship, but Penny hates the garish artwork and discreetly attempts to dispose of it, with help from Bernadette.
Episode 18 - The Werewolf Transformation
Sheldon's well-organised world is turned upside down when he learns that the barber who has cut his hair for years has passed away.
As his orderly routines descend into chaos, he is forced to act like a hippy in order to match his shaggy new hairstyle.
Howard is sent to Houston for the gruelling NASA training programme and shares horrific stories about his experiences with Bernadette via Skype.
Episode 19 - The Weekend Vortex
Amy gets upset with Sheldon when he breaks his promise to accompany her to her aunt's birthday party and instead opts to join the guys for a Star Wars video game marathon lasting the entire weekend.
Later, Penny convinces Amy that she should confront Sheldon about the matter and demand an apology.
Episode 20 - The Transporter Malfunction
Penny buys Leonard and Sheldon some Star Trek memorabilia, but she is irked when they refuse to play with the toys in case removing them from the packaging diminishes their value.
Later, prompted by a guilty conscience, Sheldon dreams that one of his Star Trek figures is developing a life of its own.
Meanwhile, desperate to find a 'plus one' to take to a wedding, Raj finally gives up and asks his parents to set him up with a date.
Episode 21 - The Hawking Excitation
Stephen Hawking comes to lecture at the university for a week, and Wolowitz is given the task of maintaining his wheelchair, making Sheldon green with envy.
When Sheldon begs Wolowitz to introduce him to his hero Hawking, Wolowitz takes full advantage and only agrees after making Sheldon carry out a series of humiliating tasks, including doing his laundry, cleaning his room, and taking his mother dress shopping.
Episode 22 - The Stag Convergence
Leonard, Sheldon and Koothrappali throw a classy bachelor party for Wolowitz, during which some stories about the future bridegroom's colourful sexual history are accidentally revealed.
When Bernadette hears about it, she becomes upset and threatens to call off the wedding. Can Wolowitz win her over with a convincing explanation and a heartfelt apology to get the nuptials back on track?
Episode 23 - The Launch Acceleration
When NASA tells a nervous Wolowitz that his space mission has been rescheduled, he tries to use the wedding as an excuse not to go.
But he's forced to agree when he realises that Bernadette's father only likes him because he's an astronaut.
Amy develops a cunning psychological plan to bring Sheldon closer. Meanwhile, Penny agrees to sleep with Leonard again, but freaks out when he accidentally asks her to marry him in the middle of the act.
Episode 24 - The Countdown Reflection
Bernadette decides that she wants to be married to Wolowitz before his NASA space mission takes place. They scramble to organise a wedding ceremony at City Hall in the short time available, but their plans go awry.
Can their friends find them an ordained minister and a romantic wedding venue before it's too late? All is revealed as the gang gather round the TV to watch the Space Shuttle, with Wolowitz on board, preparing to launch...
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...Episode Guide >
Leonard and Amy take an unexpected road trip to Arizona to pick up Sheldon when his epic railway journey ends in chaos.