Castle to Host Firefly Reunion With Nathan Fillion and Adam Baldwin

Firefly fans, rejoice: Mal and Jayne are coming together again — on ABC’s Castle.

In his first post-Chuck gig, Adam Baldwin will be reunited with his former sci-fi series co-star Nathan Fillion on the hit ABC drama.

As first reported by TV Guide Magazine, Baldwin will guest-star in a spring episode of Castle as a “rough-and-tumble” detective named Ethan Slaughter. (John Casey would approve, no?)

Slaughter is said to show Castle a dirtier side of law enforcement, one that gives him a new, dangerous perspective on future cases that will ultimately put the mystery writer in harm’s way by season’s end.

Baldwin and Fillion also starred together in Firefly‘s 2005 big-screen foray, Serenity.