The Big Bang Theory

When The Big Bang Theory beams back Sheldon's archnemesis, Wil Wheaton, on the October 13 episode, the Star Trek: The Next Generation alum will be joined by Brent Spiner, aka Commander Data. While Sheldon (Jim Parsons) has despised Wil ever since he failed to show at a sci-fi convention, exec producer Bill Prady believes that "of all the Star Trek characters Sheldon would love the most, we thought Data, the android [who has] trouble fitting in and wants emotions, is pretty close to his heart."

On principle, Sheldon declines an invite to a party at Wil's house, but "I attend and share root beer with Brent," teases Johnny Galecki, who plays Leonard. "Sheldon is very upset with Leonard for going, seeing it as a betrayal to their friendship." But expect some party crashing: "It will be hard for Sheldon to stay away," adds Prady.

Costar Kaley Cuoco admits that, like her character Penny, she's one of the few people on set who doesn't get the whole Star Trek fascination. "I was like, 'And you are?'" she says of the guest stars. "Absolutely no clue."

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