The murders of two female students are unsolved when another young woman goes missing in Minneapolis, sparking fear that a serial killer is on the loose. Police efforts to apprehend the offender stall and a prominent humanitarian couple intervene and hire Ailsa Craig, a young private investigator. Tired of tracking dead-beat dads and cheating spouses for a living, Ailsa jumps at the opportunity but gets more than she bargained for when the philanthropists insist she persuade celebrated investigator James Blackwood out of retirement to work on the case. Intent on recruiting the renowned sleuth, Ailsa visits him at his remote sheep farm in Canada, but he is reluctant to join the quest. The case evolves into a high-energy search for a serial killer like no other and the County Sheriff calls in the FBI, who assume control of the investigation. Undeterred, Ailsa Craig independently pursues the killer to prove her skill as an investigator when, unexpectedly, the tables turn on Ailsa with chilling consequences.