Melissa Rauch

As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.

Sheldon vows to destroy Kripke while Wolowitz tries not to destroy his new relationship with Bernadette.

An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.

After overhearing that Wil Wheaton is entering a trading-card competition, Sheldon decides to enter it himself.

Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.

Leonard is aghast to find out a secret of Penny's: she believes in psychics.