The body of an inmate who tried to escape in 1968 from a now-closed state penitentiary is discovered when a sinkhole opens up, and Lilly must determine if he was murdered. The evidence suggests that the man was the victim of foul play and Lilly learns that he had escaped from the prison twice before.

Lilly reopens a 1990 murder case in which a prep-school girl with bizarre markings on her body was found dead in a local swimming hole, after a present-day victim with similar markings is discovered at the same place. The investigation reveals that the victim of the earlier crime was routinely tormented by a trio of classmates who invited her to a sleepover the night she was killed.