When two polite, well-dressed social workers appear at Brenda Scupham's humble home claiming to be investigating reports of child abuse, she makes every effort to be cooperative. She even complies when Mr. Brown and Miss Peterson say they must take her seven-year-old daughter, Gemma, away for overnight tests. It is only when they fail to return Gemma the following afternoon that Brenda realizes something has gone terribly, unthinkably wrong.
As days go by with no sign of the little girl, Detective Chief Inspector Alan Banks and Detective Superintendent Gristhorpe begin to lose hope of finding her alive.
At the same time, Banks is investigating a particularly grisly, cold-blooded murder at the site of an abandoned mine. Gradually the leads in the two cases converge, guiding Gristhorpe and Banks to one of the most truly terrifying villains they will ever meet.