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.
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