When pretty and popular teenagers Piper Hadley and Tash McBain disappear one Sunday morning, the investigation captivates a nation but the girls are never found.

Three years later, during the worst blizzard in a century, a husband and wife are brutally killed in the farmhouse where Tash McBain once lived. A suspect is in custody, a troubled young man who can hear voices and claims that he saw a girl that night being chased by a snowman.

Convinced that Piper or Tash might still be alive, clinical psychologist Joe O'Loughlin and ex-cop Vincent Ruiz, persuade the police to re-open the investigation. But they are racing against time to save the girls from someone with an evil, calculating and twisted mind . . .