A mysterious stranger with no memory arrives in Mountaincrest, where he's attacked by a local who tries to rob him. The stranger transforms into an animal and kills his attacker, leading Deputy Ben Clovey to pursue him. As the search for the beast intensifies, a man named Duncan Marsh shows up in town, claiming to have amnesia after a car accident. However, he flees, sparking a debate between Sheriff Haines, who wants to capture the werewolf alive, and the doctors who are determined to kill it.