With his friends on dates, Raj must face his loneliness. Also, Wolowitz is caught in an argument between Bernadette and his mom, even while he's in space. more
Penny confesses that something is wrong with her relationship with Leonard to the girls, but she’s not sure what it is and feels like she might need to break up with him. While at the movies with the... more
Sheldon hires an assistant named Alex, an attractive female grad student. Amy gets incredibly jealous of Sheldon having a female assistant, but it turns out that Alex is actually more interested in Leonard.... more
When Wolowitz returns from space, he doesn't get the hero's welcome he expected. Meanwhile, Game Night turns into a battle of the sexes. more
The gang celebrates Halloween at Stuart's comic book store. Meanwhile, Leonard seduces Penny with science. more
Sheldon's relationship with Stephen Hawking is threatened over a game of "Words with Friends," and Penny secretly enrolls in a class at the local college. more
Wolowitz struggles with moving out of his mother's house. Meanwhile, Sheldon is caught in the middle of an argument between Amy and Wil Wheaton. more
Howard and Raj try to get to the bottom of why Sheldon disappears every afternoon at 2:45. Meanwhile, Leonard and Penny deal with jealousy in their relationship. more
When the University reassigns Sheldon's parking spot to Wolowitz, their fight affects the whole gang. more
Sheldon tries to nurse a sick Amy back to health, while Wolowitz prepares for an upcoming fishing trip with his father-in-law. more
Sheldon unwillingly revisits some Christmas memories during a lively game of Dungeons and Dragons, while Penny, Bernadette and Amy try to find the perfect girl for Raj when he joins the girls for ladies... more
Sheldon gets accused of sexual harassment at the University and winds up getting Leonard, Raj and Wolowitz in trouble. more
While the guys take a road trip to a comic book convention dressed as "Star Trek: The Next Generation" characters, the girls stay home and try to interpret a comic book. more
Sheldon is forced to work with Barry Kripke and faces a crisis of confidence. Meanwhile, Howard and Raj spend $1,000 on action figures of themselves. more
When Sheldon and Leonard fight, it affects Penny and Amy's living arrangements. Meanwhile, Raj takes care of Mrs. Wolowitz while Howard is away. more
While the guys try to give their significant others the perfect Valentine's Day, Raj and Stuart throw a "lonely people" party at the comic book store. more
After a terrible date, Koothrappali vows to never leave his apartment. Meanwhile, Penny actually impresses Sheldon with her acting skills. more
Back to school! Leonard, Sheldon and Howard try to advance the cause of women in science by speaking with junior high girls about their future careers, while Raj plans his date with Lucy (guest star KATE... more
Howard struggles with whether or not he should open a letter from his father, and Leonard and Penny throw a "grown-up" cocktail party at the apartment. more
Leonard, Sheldon and Raj fight for tenure at the University, and the competition heats up when the girls get involved. more
Sheldon feels lost after one of his favorite TV shows gets canceled too soon and Amy tries to help him get over his compulsive need for closure. Meanwhile, Raj discovers a secret about his new love interest,... more
Sheldon and Leonard hire Professor Proton, the host of their favorite childhood TV show, to perform. Also, Howard and Bernadette run into trouble babysitting Raj's dog. more
When the girls' trip to Vegas falls through, the guys invite them to play Dungeons & Dragons, causing Sheldon and Amy's relationship to take an unexpected turn. Meanwhile, Koothrappali and Lucy go on a... more
A new success for Leonard makes Sheldon very jealous and throws Penny for a loop. Meanwhile, Koothrappali pushes Lucy too far in their relationship. more