In this unremittingly serious, undistinguished, yet well-acted tale of the supernatural, two different men are possessed by spirits of Native Americans after they separately wander into a sacred burial ground, angering the spirits enough for them to retaliate. When John (Gabriel Walsh) and Sybil (Susan Strasberg) come home with their son after a trip to the Mojave Desert, they bring an unusual stone back as a memento of the trip. The stone seems to cause strange noises and other inexplicable phenomena, and then one day their son is killed by a truck driver in a freak highway accident. As the father's mental condition deteriorates from that point onward, it is revealed that both John and the truck driver are possessed by angry spirits of Native American warriors, and unless the spirits are exorcised, the two men are destined to meet in a battle to the death. Director John Bender cuts back and forth between the truck driver and the father, which might confuse (or even irritate) some viewers since in the beginning there is no explanation of how or why the two men are connected.