Archaeology Professor Jack Foreman begins to suspect it is an ancient Native American demon inadvertently set loose when he and a student explored a five-hundred-year-old ruin.

     KTVC Weatherman Matt Sharp is fascinated by the storm because it doesn't appear on radar. He wants to track it and use it as a springboard to national prominence.

     Police Detective Greg Johnson is assigned to the case and teamed with Navajo Tribal Policeman Ed Twohats Redfield from New Mexico. Together, they seek explanations to separate but similar disasters in both states.

     Simultaneously, medicine people from twelve different Native American tribes become aware of the creature and begin to gather on the Salt River Indian Reservation. They know the demon is real for it speaks in their minds, whispering dire threats, cajoling and maneuvering in an attempt to prevent them from gathering. Despite tribal rivalries, they must work together to stop the killing and destruction.

     Feeding on life energy like a vampire, the demon grows, doubling and trebling in size in hours, ultimately seeking to tap an unlimited storehouse of energy - the Palo Verde Nuclear Power Plant outside Phoenix.