"Something is on the prowl in the forests and foothills outside the small Wyoming town of Potter's Field, something that mutilates but does not feed, that kills indiscriminately and without reason, at night, by moonlight. As the body count mounts, police chief Nathan Slaughter and the town's medical examiner try to find out who or what is doing the killing....Morrell embeds compelling human drama in a taut, hell-for-leather plot consisting of equal parts police procedural, medical detective story, biological horror story, disaster novel and Gothic thriller."- Washington Post Book World