8.21 Hell to Pay
Original air date: May 9, 2016

“Hell to Pay” – When an axe-wielding, escaped psychiatric inmate drops dead in Castle’s P.I. office, Castle and Beckett’s investigation leads Castle to suspect the victim’s death could be the work of the Antichrist, on “Castle,” MONDAY, MAY 9 (10:00-11:00 p.m. EDT), on the ABC Television Network.

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