When two social workers investigating reports of child abuse appear at Brenda Scupham's door, her fear of authority leads her to comply meekly with their requests. Even when they say that they must take her seven-year-old daughter Gemma away for tests.
It is only when they fail to return Gemma the following day that Brenda realises something has gone terribly wrong. Particularly worrying is the calculated manner of the abduction, and the fact that one of the "social workers" was a woman. For Detective Chief Inspector Alan Banks, ritual Satanic abuse is a dreadful possibility.
At the same time, Banks is investigating a particularly grisly murder at the site of an abandoned mine. Gradually, the leads in the two cases converge, guiding Banks to one of the most truly terrifying villains he will ever meet.