Episode 11
The Bath Item Gift Hypothesis
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
Season 2
This season, Leonard gets a girl. So does Sheldon. Howard drives the Mars Rover into a ditch. Raj woos a terminator. Gorgeous girl-next-door Penny falls under the spell of Age of Conan. And super-smart, ueberconfident Leslie Winkler reduces mere men to spineless jellyfish.
All Episodes
Episode 1
The Bad Fish Paradigm
September 22, 2008
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
Episode 2
The Codpiece Topology
September 29, 2008
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
Episode 3
The Barbarian Sublimation
October 6, 2008
Sheldon creates a monster when he introduces Penny to online gaming.
Episode 4
The Griffin Equivalency
October 13, 2008
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
Episode 5
The Euclid Alternative
October 20, 2008
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
Episode 6
The Cooper-Nowitzki Theorem
November 3, 2008
Sheldon and the gang are confused when a young grad student is attracted to him.
Episode 7
The Panty Piñata Polarization
November 10, 2008
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
Episode 8
The Lizard-Spock Expansion
November 17, 2008
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
Episode 9
The White Asparagus Triangulation
November 24, 2008
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
Episode 10
The Vartabedian Conundrum
December 8, 2008
Leonard asks Penny for advice when his new relationship starts moving too fast.
Episode 11
The Bath Item Gift Hypothesis
December 15, 2008
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
Episode 12
The Killer Robot Instability
January 12, 2009
Penny's criticism of Wolowitz's romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for.
Episode 13
The Friendship Algorithm
January 19, 2009
Sheldon creates a scientific procedure for making friends.
Episode 14
The Financial Permeability
February 2, 2009
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
Episode 15
The Maternal Capacitance
February 9, 2009
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
Episode 16
The Cushion Saturation
March 2, 2009
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
Episode 17
The Terminator Decoupling
March 9, 2009
Leonard, Sheldon and Wolowitz are ecstatic to learn that a famous science-fiction actress (Summer Glau) is on board the train they are taking to San Francisco.
Episode 18
The Work Song Nanocluster
March 16, 2009
Penny's home business turns into a complete nightmare when Sheldon takes over.
Episode 19
The Dead Hooker Juxtaposition
March 30, 2009
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
Episode 20
The Hofstadter Isotope
April 13, 2009
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
Episode 21
The Vegas Renormalization
April 27, 2009
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
Episode 22
The Classified Materials Turbulence
May 4, 2009
Penny's second date with Stuart sees her making a comment that gives Leonard new hope for a relationship with her. Wolowitz realizes there's a crucial error in a NASA project he's working on.
Episode 23
The Monopolar Expedition
May 11, 2009
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.