Leonard & the Big Bang Theory gang go to a fancy dress party and end up switching places with the crew of the Starship Enterprise (original series). They have to deal with the voyage of the Starship Enterprise while trying to figure out how to get home. Meanwhile Captain Kirk & crew have the same problem in The Big Bang Theory universe.

Set in a slightly different alternative universe of The Big Bang Theory. Stuart meet Alice again (whom Leonard dated briefly). Alice asks him to work on a new comic with her and their relationship develops. But will Stuart's lack of dating experience hinder him in his attempts to win the girl?