When Elsa Flanagan walks her dog in a meadow near a railroad track one spring evening, she certainly doesn't expect to witness a terrifying tragedy. A commuter train passes a man lying on the tracks right in front of her. The section of the track is nicknamed the "suicide mile", but it soon becomes clear that the man was the victim of a premeditated murder.

Detective Sergeant Kay Hunter comes to a chilling conclusion: the incriminated track got its reputation because of a brutal serial killer. Does he choose his victims at random, or is there a connection between them? Kay must investigate a series of previous apparent suicides to see if the same killer is behind them. In addition, she also tries to figure out who is behind the professional vendetta against her. When another murder occurs, Kay realizes that the perpetrator has changed his schedule. A deadly plan has been set in motion and time is inexorably running out...