Eliza Dushku to guest on 'Big Bang Theory'

'Dollhouse' actress playing an FBI agent in seventh episode

Eliza Dushku is joining the gang on "The Big Bang Theory."

The "Dollhouse" actress has signed on to guest star in the seventh episode of the new season, which premieres tonight at 8 p.m. on CBS, a rep for the series confirmed to THR.

Dushku will be playing an FBI agent who interviews Wolowitz's (Simon Helberg) friends so that he can get a top-secret security clearance.

"The Big Bang Theory" will be going up against some stiff competition Thursdays, with NBC's quirky comedy "Community," Fox's "Bones," ABC's freshman mockumentary drama "My Generation" and the CW's "The Vampire Diaries" all airing at the same time.

The series stars Emmy winner Jim Parsons, Kaley Cuoco (who will be missing a few episodes due to an injury), Johnny Galecki, Helberg and Kunal Nayyar.