Alan Tudyk guest-starred in episode 8 (season 2) of The Rookie, which was called Clean Cut. It wasn't just a cameo, he was in quite a bit of the episode.
Considering how many Firefly alums guest-starred on Castle during its run, it's kind of amazing that Tudyk never did.
Considering how many Firefly alums guest-starred on Castle during its run, it's kind of amazing that Tudyk never did.