Series 3 Episode 13
Leonard and Sheldon's flat is burgled. Determined to outwit any thieves, the gang work on creating a state-of-the-art security system to protect the apartment. Can they deter the burglars?
Series 3 Episode 1
The Electric Can Opener Fluctuation: Sheldon heads to Texas after learning that his friends meddled with his expedition data
Series 3 Episode 1
Series 3 Episode 2
The Jiminy Conjecture: Leonard and Penny feel awkward around each other after their romantic liaison
Series 3 Episode 2
Series 3 Episode 3
The Gothowitz Deviation: Sheldon tries to modify Penny's behaviour using chocolate
Series 3 Episode 3
Series 3 Episode 4
The Pirate Solution: Raj reluctantly accepts a job offer from Sheldon so that he won't be sent back to India
Series 3 Episode 4
Series 3 Episode 5
The Creepy Candy Coating Corollary: Sheldon enters a competition that pits him against his nemesis, Wil Wheaton from Star Trek
Series 3 Episode 5
Series 3 Episode 6
The Cornhusker Vortex: Sheldon teaches Leonard about football so that he can fit in with Penny's friends
Series 3 Episode 6
Series 3 Episode 7
The Guitarist Amplification: Sheldon is upset when Leonard and Penny argue about Penny's male friend staying over
Series 3 Episode 7
Series 3 Episode 8
The Adhesive Duck Deficiency: Sheldon has to come to Penny's rescue after she dislocates her shoulder in the shower
Series 3 Episode 8
Series 3 Episode 9
The Vengeance Formulation: Howard is scared about committing to Bernadette, so he avoids her
Series 3 Episode 9
Series 3 Episode 10
The Gorilla Experiment: Howard and Penny are jealous when Bernadette is fascinated with Leonard's physics project
Series 3 Episode 10
Series 3 Episode 11
The Maternal Congruence: Leonard's hurt when his mum arrives unannounced and then learns Sheldon knew of the visit
Series 3 Episode 11
Series 3 Episode 12
The Psychic Vortex: A rift forms between Leonard and Penny when he ridicules her belief in psychics
Series 3 Episode 12
Series 3 Episode 13
The Bozeman Reaction: The gang work on creating a state-of-the-art security system after the flat is burgled
Series 3 Episode 13
Series 3 Episode 14
The Einstein Approximation: Sheldon gets a job at the Cheesecake Factory to kick-start his creativity
Series 3 Episode 14
Series 3 Episode 15
The Large Hadron Collision: Sheldon's jealous when Leonard asks Penny to visit the Large Hadron Collider with him
Series 3 Episode 15
Series 3 Episode 16
The Excelsior Acquisition: Sheldon misses a chance to meet Stan Lee when he's summoned to court for a driving offence
Series 3 Episode 16
Series 3 Episode 17
The Precious Fragmentation: The gang squabble over a ring that they believe was used in The Lord of the Rings movies
Series 3 Episode 17
Series 3 Episode 18
The Pants Alternative: Sheldon earns an award but is scared of making a speech at the ceremony to receive it
Series 3 Episode 18
Series 3 Episode 19
The Wheaton Recurrence: Leonard tells Penny that he loves her but doesn't get the response he hoped for
Series 3 Episode 19
Series 3 Episode 20
The Spaghetti Catalyst: Sheldon tries to hide his friendship with Penny from Leonard
Series 3 Episode 20