A series of bizarre assaults is mystifying Boston police: an unknown attacker is viciously beating random strangers and leaving a note quoting an old warning about witchcraft. History professor Alex Maple was one of the victims, and now he's gone missing. Vickie Preston is certain that someone has taken her friend for malicious purposes. She's having blood-drenched visions that seem to be staining her waking life, and the escalating attacks suggest...