Take a first look at Season 2 Episode 17, ''The Terminator Decoupling''

A train trip to San Francisco takes a major detour when Leonard (Johnny Galecki), Sheldon (Jim Parsons), Wolowitz (Simon Helberg) and Raj (Kunal Nayyar) discover that beautiful sci-fi actress Summer Glau (Terminator: The Sarah Connor Chronicles) is onboard, on The Big Bang Theory, Monday, March 9 (8:00-8:30 PM, ET/PT) on the CBS Television Network. The episode also features a cameo by Nobel Laureate Dr. George Smoot.

To Watch The Preview Click here.

Source here