Someone is killing sexual predators in the city of Markham. Leaving no trace, the murderer clearly has a specific motivation: every victim has been connected to horrific crimes of sexual abuse.

Detectives Cathy Stevens and David Hearns must put their personal feelings about the victims aside to crack the case. Their investigation leads them to a support group for victims of sexual abuse, a man with a driving need for human blood, and a cult that traces its history back to the biblical flood.

Crossing their paths more than once are Kaye Fowler and Amy Louise Crawford. Driven by her own tragic past, Kaye works tirelessly to help those who can't help themselves. Her impression upon meeting nine-year-old Amy Louise is that the young girl seems to fit this description. Despite her sweet, optimistic personality, she has been continually shifted from one foster home to another. In her efforts to save Amy Louise from a potentially dreadful fate, Kaye uncovers something extraordinary about the child.

As Kaye and the detectives unearth the startling darkness at the heart of their own city, each suspect they meet will have to make the choice to either embrace that darkness-or find the light.