Melissa Rauch

Sheldon and Raj go to a university party, Leonard disapproves of Penny's belief in psychics and Raj lusts after a girl named Abby whom he meets at the party.

Sheldon has `theorist block' and is finding it difficult to muddle through a formula he's been working on. Taking inspiration from Albert Einstein, he takes a job at the Cheesecake Factory to try to kick start his creativity.

An embarrassing secret of Wolowitz's is revealed; Raj and Sheldon get into a war at work.

Tensions run high when Bernadette runs into her hulk of an ex-boyfriend at a science conference. Threatened by Bernadette's ex-boyfriend, Wolowitz has an argument with Bernadette and causes chaos.

Leonard realizes he's the only one without a girlfriend, while Sheldon wants to get rid of his.

Sheldon enters a competition but is annoyed when he finds out that `Star Trek' actor Wil Wheaton is participating because Wil cancelled his appearance at a sci-fi convention that Sheldon had attended as a child.