The story is set in the fictional small town of Tarker's Mills, Maine. A werewolf is viciously killing people and animals and a strange incident takes place at each full moon. The otherwise normal town is living in fear. The protagonist of the story is Marty Coslaw, an eleven-year-old boy in a wheelchair. The story goes back and forth from the terrifying incidents to Marty's youthful day-to-day life and how the horror affects him.