After a family is murdered near a remote western town, a US Federal Marshall is sent to investigate. He discovers that the town and surrounding farms is emptying, due in part to the threat of a psychopath having been let loose on the residents. The Marshall has to discover not only who is the killer and how to stop him; but also who let him loose and why.

Despite vocal objections from Warden Blakely, prison psychologist Diana Purlow journeys deep inside the mind of serial killer Jesse Mowat in a desperate attempt to reveal the source of his psychotic tendencies.