Melissa Rauch

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

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.

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

After he's humiliated on National Public Radio, Sheldon vows to destroy Kripke (guest star John Ross Bowie), and the guys help Sheldon exact his revenge. Meanwhile, Wolowitz tries not to destroy his new relationship with Bernadette (guest star Melissa Rauch). Katee Sackhoff (Battlestar Galactica) makes a cameo as Wolowitz’s dream girl.

Penny feels left out when Bernadette shows an interest in science and asks Sheldon to teach her about science. Eventually, she surprises everyone with what she's learned.

When Penny's dad comes to visit, Leonard discovers that she told her parents they were back together because they always had a soft spot for him.