Miles away, an alarmed mother receives from her estranged husband an unsettling letter strained with bloody fingerprints. And all across California, children are falling victim to a monstrous change - and their parents, to a mounting fear. Social worker Carrie Daniels and reporter Brian Howells are determined to find the link between these baffling events. But they shouldn't look too deeply into the lives of the victims. It's quite dark there. And God help them, they won't like what they find.