Adam Baldwin to Reunite with Nathan Fillion on Castle

ABC is about to host a Firefly reunion.

Network sources confirm to TV Guide Magazine that Adam Baldwin - most recently known for Chuck, but Jayne Cobb to Nathan Fillion's Mal Reynolds on the aforementioned cult favorite - will guest star this spring on Castle as a detective named Ethan Slaughter.

Viewers can expect these two to team up, as Slaughter shows Castle a dirty side of the law and, through their alliance, places the show's title character in danger.

Baldwin is only booked for one episode at the moment.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.