The Terminator Decoupling

Summary
The four guys head to San Francisco on the train for a conference. Sheldon forgets his flash drive and has to call Penny for help retrieving it. Meanwhile Summer Glau (Firefly, Terminator: The Sarah Connor Chronicles) is on the same train and Raj and Howard try to hit on her.

Critics
"A nice plug for the Sarah Connor Chronicles provides the guys with an enjoyable new setting to deliver the same old jokes." - The TV Critic's Review