Prompted by the unearthing of a human skull in the woods near his house, Bill Reyner begins an investigation into a 20-year-old unsolved murder. Unlike the police, he becomes involved with the characters associated with the deed. His entanglement deepens, as does his knowledge of the case. Joining the deadly and insane cult, he intends to trap them, only to find the tables are turned and he becomes the quarry. At every turn, the Mania is ahead of him. With full knowledge of their actions but no physical evidence, he has nowhere to hide and no one to call for help. Bill's only option is to fight them on their own terms.