Castle › Season 4

S4 E21: Headhunters

Name: Headhunters
Released: 2012-04-16

With tensions rising between Castle and Beckett, Castle finds himself a new partner -- Detective Ethan Slaughter (guest star Adam Baldwin, "Firefly"), a tough and colorful cop from the city's gang unit. But Castle gets more than he bargained for when Slaughter shows him a grittier side of police work that puts Castle in the line of fire like never before

Air date	Apr 16, 2012
Runtime	44 minutes
TMDB rating	★ 8.1/10