It's been four months since Sheldon met neuro-biologist Amy Farrah Fowler, who Sheldon believes is his intellectual equal as well as his emotional female equivalent. Alth ...

After Sheldon scientifically calculates his life expectancy, he is dismayed to learn that he will be a few years short of the time when he will be able to transfer his co ...

Despite not considering her his girlfriend and visa versa, Sheldon and Amy are spending a lot of time together. This situation irks the gang, but especially Leonard as Sh ...

Howard is still uncomfortable in even seeing Bernadette, which is obvious when he spots her at work at the Cheesecake Factory. But when Bernadette enters his dreams inste ...

With Amy in Sheldon's life (despite they still not being boyfriend/girlfriend), Bernadette in Howard's life, and even Raj now having a girlfriend (she being deaf so it do ...

Raj's sister, Priya, a corporate lawyer, has a 24 hour layover in Los Angeles on her way to Toronto on a work trip. When the guys met her the first and only time five yea ...

Howard has been chosen to work on the Defense Department's Laser Equip Surveillance Satellite project. He needs security clearance to work on the project which means the ...

Leonard, Sheldon, Howard, Raj and Amy are planning to go a see a special screening of Raiders of the Lost Ark (1981) with 21-seconds of previously unseen footage which, f ...

Penny's father, Wyatt, is in Pasadena for a visit. Leonard learns that Penny told her father that she and Leonard got back together again, as Leonard is the one and only ...

Amy experiences strange symptoms, which she believes are signs of a flu. They include an elevated heart rate, sweaty palms, dry mouth, and localized vascular throbbing. A ...

Penny starts dating Zack again. Used to being the target of bullying, Leonard, Sheldon, Howard and Raj instead bully Zack through their implications to him that he's stup ...

Leonard comes up with an idea to develop a smart phone app that would use handwriting recognition software to help in solving their differential equations problems. Altho ...

Penny initially declines an invitation from Amy Farrah Fowler, who considers Penny her best friend, to accompany her, Sheldon, Leonard, Howard, Raj and Bernadette to a we ...

Raj laments the fact of his single status. An admission by Bernadette totally preoccupies Raj's thoughts in his fragile state. Meanwhile, Sheldon has just conducted a gue ...

The university's President Siebert orders the guys to attend a fundraising party. Leonard, Howard and Raj are more than happy to go for the free food and drinks and the p ...

Bernadette and Howard discuss where their relationship is heading when Howard once again can't stay the night since he has to look after his mother. When Bernadette broac ...

It's Thursday night, which in Sheldon's world means that the guys are coming over for pizza. However, Leonard informs him that he's going over to Raj's to hang out with P ...

Priya and Leonard's relationship has gotten to a serious stage where Leonard is wearing the clothes that she picks out for him and is trying to wear contact lenses on her ...

Sheldon is totally distraught - even to the point of calling in the police and trying to call in the FBI - after someone has hacked into his World of Warcraft (2004) acco ...

Starting with Penny to Amy, a rumor quickly spreads amongst Leonard, Sheldon, Raj and Priya that Bernadette is planning on breaking up with Howard. This rumor is especial ...

When Sheldon formally charges Leonard with breaching the roommate agreement by taking a shower with Priya in the apartment bathroom when Sheldon had a call of nature (con ...

Priya and Leonard ask Howard and Bernadette to join them for a couples only dinner at the Koothrappalis' apartment. Amy sees the invitation as Priya's way of conquering a ...

Howard and Bernadette have started planning their wedding, but they have failed either to tell Bernadette's parents or Mrs. Wolowitz that they are even engaged. To ingrat ...

Bernadette has just announced that her dissertation has been accepted, meaning that she will soon get her Ph.D. On top of that, she has received a lucrative job offer wit ...