Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.
Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.
Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.
Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-world opportunity.
Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.
When Stuart asks Amy out on a date, Sheldon must confront his feelings and consider where his relationship with Amy is going.
Leonard must face his fears after being contacted by his high school tormentor.
Sheldon gets in trouble with Amy when he isn't impressed by her recent accomplishment, and Howard must come to grips with Bernadette's dislike of children.
When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.
When Wolowitz gets to work with Stephen Hawking, Sheldon is willing to do anything to meet his hero.
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
Raj and Howard try to to figure out why Sheldon disappears at 2:45 every afternoon; jealousy arises in Penny and Leonard's relationship.
During a game, Sheldon revisits Christmas memories; Amy, Penny and Bernadette look for a date for Koothrappali.
When Sheldon is accused of sexual harassment, he ends up getting Raj, Leonard and Wolowitz in trouble.
A fight between Sheldon and Leonard impacts Amy and Penny's living arrangements; while Howard is away, Raj helps Mrs. Wolowitz out.
After a bad date, Koothrappali decides to never leave his apartment; Penny's acting skills impress Sheldon.
Leonard, Sheldon and Wolowitz talk to junior high girls about science-related careers; Raj plans a date with Lucy.
Amy tries to help Sheldon get over his compulsive need for closure when one of his favorite TV shows is canceled; Raj discovers a secret about Lucy.
Amy and Sheldon's relationship takes a surprising turn during a game of "Dungeons & Dragons"; Lucy and Koothrappali have an awkward date.
When Leonard receives an exciting opportunity to work overseas, Penny and Sheldon are thrown for a loop.
Leonard and Sheldon's friendship is tested; Wolowitz's relationship with his mom causes a threat to his masculinity.
Beverly Hofstadter writes a psychology book about Leonard which Penny buys and reads. Sheldon wants to ruin something for Amy after she ruins an Indiana Jones movie for him. Raj and Stuart try ...
Sheldon's latest scientific breakthrough leaves him feeling like a fraud; a romantic gesture between Howard and Bernadette causes Penny to up her game with Leonard.
When Professor Proton asks Leonard for help with an experiment, Sheldon retaliates by befriending Proton's rival, Bill Nye.
When a mistake comes to light, Sheldon makes Leonard walk a mile in his shoes; Penny decides to confront Raj's ex.
Sheldon tries to relax after he is forced to take a vacation. Meanwhile, Leonard struggles to be supportive of Penny after she quits her job, and Bernadette seeks Stuart’s help in replacing one ...
Bernadette tries to negotiate peace between Sheldon and Wolowitz; Penny receives an embarrassing offer; Raj wants Amy to write to a woman on his behalf.