Bestselling author Neil Gaiman will appear on the CBS TV sitcom Big Bang Theory, which tweeted a spoiler alert: "Mark your calendars! On the April 19 episode of The #BigBangTheory, special guest star @neilhimself will put Stuart's comic book store on the map, and (spoiler alert!) Sheldon won't like it."
Gaiman tweeted: "Can such things BE?"
Here's the network's summary of "The Comet Polarization" episode: "Sheldon's comic book store experiences changes when writer Neil Gaiman puts Stuart's store on the map. Also, Koothrappali takes credit for Penny's astronomical discovery, and friendships are threatened."