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…

Jane is concerned about go to a high school reunion, Petra learns about Jane’s request.

Leslie and Ben come under fire for participating in an old Pawnee tradition. April and Ron go on a scavenger hunt. Donna and Garry stroll down memory lane.