The Servants of Twilight — Dean Koontz

An ordinary parking lot in southern California. Christine Scavello and her six-year-old son are accosted by a strange old woman. "I know who you are," she snaps at the boy "I know what you are." A scream, a threat - and then a grotesque act of violence. Suddenly Christine's pride and joy, her only son, is targeted by a group of religious fanatics. They've branded him the Antichrist. They want to kill him. And they are everywhere...