A young Bay Area woman, Sonia Mattingly, goes missing while taking a summer jaunt in an old mining town in California's scenic Sierra Mountains. Gail Brevard and her partners are called in to investigate the case and she decides she must go undercover in order to retrace Sonia's steps and get to the truth of the matter.
Gail soon discovers that a demented mad man has been operating in the town at will, wreaking havoc and heartbreak with each evil act of betrayal. A deadly arson fire followed by an unexplained explosion at an old mine threaten not only the community, but Gail's very life as well.
Can she and her colleagues put all the pieces of the puzzle together and bring the villain to justice before he strikes again?