Season 2, Episode 17 - The Terminator Decoupling
Aired March 9, 2009
When the guys take a trip to San Francisco for a physics convention, they are stunned to discover Summer Glau is a passenger on the train. Leonard, Howard and Raj each take turns trying to impress the Terminator: The Sarah Connor Chonricles star. Meanwhile, after Sheldon realizes he left an important flash drive at home, his disappointment soon turns to annoyance when he must contact Penny to retrieve a document on the flash drive.