4x14 The Blue Butterfly
First Aired: Feb. 06, 2012 on ABC
Summary: When Castle and Beckett investigate the killing of a treasure hunter, they discover the case is linked to a mysterious homicide from 1947 involving a hard-boiled private detective. Castle realizes the only way to solve the present-day murder is to solve the murder from the past. The 1947…
Main Characters in this Episode
Richard Castle: [as Flynn] Always.
Kevin Ryan: We'll be taking... some of it off your hands as part of our investigation.
- Chad Everett was battling lung cancer while filming what would be his last screen appearance. He died six months after this episode aired.