The Big Bang Theory, CBS’s hip young show by—and for!nerds, is continuing its beloved trend of hiring popular sci-fi icons to stand near and talk to its cast of beautiful actors in unflattering glasses. Besides a recurring Wil Wheaton, other nerd cred donors have included LeVar Burton, Battlestar Galactica’s Katee Sackhoff, and waifish part-time Terminator Summer Glau. Now, Glau’s old Firefly co-star Nathan Fillion is joining the list with a guest appearance in the Feb. 18 episode.

Professional handsome man Fillion will be playing himself, spotted eating out at a restaurant by characters Raj and Leonard (Kunal Nayyar and Johnny Galecki, who both totally love reading comic books). The duo engages in the tried-and-true debate of whether to bug the celebrity for a photo while he’s eating dinner, or just leave him to his meal of Castle royalties and bulletproof pop-culture goodwill. Presumably, the ensuing discussion will feature banter and at least one reference to “leather pants,” much to the delight of the cackling horde of invisible ghosts who follow Galecki everywhere he goes, madly howling laughter at his slightest utterance.