The city of Moon Valley is being stalked by a savage killer that can move without sound, strike without warning, and whose howl contains a power granted only by the gods themselves. Lieutenant Hal Dillon is drawn into the killer's grisly web, and as he uncovers the incredible mystery of the killer's existence, he discovers something even more harrowing. He and the killer are united in a struggle against an enemy that has been stalking both of them for years. Hal finds himself locked in an epic battle between the forces of chaos and death, where the only way for him to win may be to disavow his own humanity. Hal and a group of his friends now must face their ultimate fears, with the fate of humanity hanging in the balance.