Season 2 (2008)
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.
Ep.1 The Bad Fish Paradigm
Air Date: 2008-09-22
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
Ep.2 The Codpiece Topology
Air Date: 2008-09-29
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
Ep.3 The Barbarian Sublimation
Air Date: 2008-10-06
Sheldon creates a monster when he introduces Penny to online gaming.
Ep.4 The Griffin Equivalency
Air Date: 2008-10-13
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
Ep.5 The Euclid Alternative
Air Date: 2008-10-20
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
Ep.6 The Cooper-Nowitzki Theorem
Air Date: 2008-11-03
Sheldon and the gang are confused when a young grad student is attracted to him.
Ep.7 The Panty Piñata Polarization
Air Date: 2008-11-10
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
Ep.8 The Lizard-Spock Expansion
Air Date: 2008-11-17
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
Ep.9 The White Asparagus Triangulation
Air Date: 2008-11-24
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
Ep.10 The Vartabedian Conundrum
Air Date: 2008-12-08
Leonard asks Penny for advice when his new relationship starts moving too fast.
Ep.11 The Bath Item Gift Hypothesis
Air Date: 2008-12-15
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
Ep.12 The Killer Robot Instability
Air Date: 2009-01-12
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.
Ep.13 The Friendship Algorithm
Air Date: 2009-01-19
Sheldon creates a scientific procedure for making friends.
Ep.14 The Financial Permeability
Air Date: 2009-02-02
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
Ep.15 The Maternal Capacitance
Air Date: 2009-02-09
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
Ep.16 The Cushion Saturation
Air Date: 2009-03-02
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
Ep.17 The Terminator Decoupling
Air Date: 2009-03-09
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.
Ep.18 The Work Song Nanocluster
Air Date: 2009-03-16
Penny's home business turns into a complete nightmare when Sheldon takes over.
Ep.19 The Dead Hooker Juxtaposition
Air Date: 2009-03-30
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
Ep.20 The Hofstadter Isotope
Air Date: 2009-04-13
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
Ep.21 The Vegas Renormalization
Air Date: 2009-04-27
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
Ep.22 The Classified Materials Turbulence
Air Date: 2009-05-04
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.
Ep.23 The Monopolar Expedition
Air Date: 2009-05-11
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.