Aired 12 years ago - Apr 16, 2012
With tensions rising between Castle and Beckett, Castle finds himself a new partner -- Detective Ethan Slaughter, 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.
Mouse over thumbnail for slideshow
Or scroll and see one by one: