
A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween.
Sheldon’s mother, Mary Cooper, comes to visit, but Sheldon is annoyed that she also spends time with the rest of the gang, instead of catering to his every demand.
Sheldon and Leonard get invited to a party at Wil Wheaton’s house, and Howard gets an out-of-this-world opportunity.
Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.
Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz.
A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya.
Penny is worried with how damaged her friendship with the guys will be in the aftermath of her sleeping with Raj while Sheldon becomes the leader of the paintball team.
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she’s regrets.
When Howard finally breaks the news to his mom that he’s engaged to Bernadette, it lands her in the hospital.
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges ...
Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.
Sheldon’s online-game account is hacked by Todd Zarnecki, who then proceeds to steal all his items prompting the guys to go on a quest to retrieve them. Penny, Bernadette and Amy discuss how Penny groomed Leonard to be ...
Sheldon is baffled by Wolowitz’s magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.
Sheldon becomes concerned when everybody begins to hang out at Raj’s apartment and discovers Leonard is the center of the group.
As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj’s sister.
A wealthy donor to the university makes Leonard consider how far he’s willing to go for the sake of science.
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend’s girlfriend.
Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
Leonard’s idea for a smartphone app derails his friendship with Sheldon.
The guys find a « super » use for Penny’s new boyfriend, Zack, when they enter a costume contest as the Justice League.
Amy finds she has sexual feelings for Penny’s ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.
Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.
While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.