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 — Season 2
S2 E1The Bad Fish Paradigm
Sep 22, 20087.922 min
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
S2 E2The Codpiece Topology
Sep 29, 20087.721 min
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
S2 E3The Barbarian Sublimation
Oct 6, 2008821 min
Sheldon creates a monster when he introduces Penny to online gaming.
S2 E4The Griffin Equivalency
Oct 13, 20087.621 min
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
S2 E5The Euclid Alternative
Oct 20, 20087.620 min
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
S2 E6The Cooper-Nowitzki Theorem
Nov 3, 20087.921 min
Sheldon and the gang are confused when a young grad student is attracted to him.
S2 E7The Panty Piñata Polarization
Nov 10, 2008821 min
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
S2 E8The Lizard-Spock Expansion
Nov 17, 20087.520 min
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
S2 E9The White Asparagus Triangulation
Nov 24, 20087.521 min
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
S2 E10The Vartabedian Conundrum
Dec 8, 2008721 min
Leonard asks Penny for advice when his new relationship starts moving too fast.
S2 E11The Bath Item Gift Hypothesis
Dec 15, 20088.221 min
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
S2 E12The Killer Robot Instability
Jan 12, 20097.521 min
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.
S2 E13The Friendship Algorithm
Jan 19, 20097.521 min
Sheldon creates a scientific procedure for making friends.
S2 E14The Financial Permeability
Feb 2, 20097.421 min
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
S2 E15The Maternal Capacitance
Feb 9, 20098.121 min
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
S2 E16The Cushion Saturation
Mar 2, 20097.521 min
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
S2 E17The Terminator Decoupling
Mar 9, 20097.621 min
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.
S2 E18The Work Song Nanocluster
Mar 16, 20097.620 min
Penny's home business turns into a complete nightmare when Sheldon takes over.
S2 E19The Dead Hooker Juxtaposition
Mar 30, 20097.620 min
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
S2 E20The Hofstadter Isotope
Apr 13, 20097.620 min
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
S2 E21The Vegas Renormalization
Apr 27, 20097.522 min
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
S2 E22The Classified Materials Turbulence
May 4, 20097.519 min
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.
S2 E23The Monopolar Expedition
May 11, 20097.521 min
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.