An advance study team from a Benwarian spaceship is sent to earth to study humans to see if any are worth saving when the planet is terraformed. Two of them befriend humans and develop a small community of friends in N. Arizona. In their travels one of them becomes possessed by a demon whose only desire is to destroy everything in its path. It lives in the mind of Travis, one of the Benwarians, wreaking havoc. Expelled from his mind, it jumps from one being to another trying to kill the two Benwarians and their friends. The aliens engage the predator in a deadly battle of survival.