And the best part? He's dressed in head-to-toe zombie garb.
Naturally, Castle's loving every second of it, and even asks the cranky medical examiner if there's any way to prove that Kyle is, in fact, a zombie.
Watch the clip below!
As entertaining as it all is, we can't forget there's a murder to solve. Kyle's teeth match the bite marks and the blood on his clothes came from the victim. According to Perlmutter, he's definitely their guy.
But the question remains: Was Kyle simply involved in a "Thriller" flashmob gone wrong, or have Castle's wildest dreams come true?
Tune in on Monday, April 30, 2012 at 10 p.m. ET on ABC to find out!