Castle

Season 4 Episode 21: Headhunters

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

Genre:

Drama, Crime

Seasons:

8

Episodes:

173

Actor:

Nathan Fillion, Stana Katic, Molly C. Quinn

Quality:

HD

Status:

Canceled

First Air:

2009

IMDb:

8.0