The plot forced the four geeks (and Summer Glau, as herself) onto a train for eleven hours, because Sheldon likes the clickety clack of the train against the rails. The boys all takes turns (except of course Sheldon) trying to hit on the erst-while Terminator, while Sheldon and Penny work via phone to try and recover Sheldon’s flash drive. It’s a pretty flimsy plot, but it allows all the characters room to goof off, and we get to see the oft-hidden talkative, charming Raj as he gets faux-drunk on alcohol-free beer and charms Glau with his talk of Slumdog Millionaire.
This is one show that really gets how to go for the best possible guest stars for its demographic. Plus I like to play the 6-degrees of Joss Whedon game, and therefore enjoyed Dr. Horrible‘s Moist chat up River.