After an archaeological team in Arizona unearths a werewolf skeleton and one of them develops symptoms of lycanthropy before dying, the dig's foreman, Yuri, tries to infect other townspeople as an experiment. When a science writer named Paul takes up residence in the town to cover the dig and develops a romantic interest in a female team member, Yuri makes Paul his next target.

An alien life form comes to Earth to help a young couple save their unborn child from the Darkside.