Nathan Fillion, Stana Katic, Jon Huertas Nathan Fillion, Stana Katic, Jon Huertas

"What the hell is this place?"

So asks Castle's Detective Kate Beckett (Stana Katic) in our exclusive peek at the drama's next episode (Monday, 10/9c, ABC). And that's just one of the many questions the episode, poses.

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Perhaps the most important one: Where is the body?When Beckett and Castle ( Nathan Fillion) discover their bloody crime scene has no victim, they begin an investigation that leads them into the world of life-extension science. As we previously reported,

William Atherton guest-stars as Ari Weiss, a researcher with a particular fondness for cryogenic freezing.

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In the video clip below, Castle and Beckett get an up-close-and-personal look at Weiss' work. And  based on Castle's (hilarious) reaction, frozen bodies aren't exactly his thing.The full episode airs Monday at 10/9c on ABC. Watch the sneak peek now: