While driving through the Nevada desert to Salt Lake, the couple Peter Jackson and his wife Mary are stopped by sheriff Collie Entragian because their car has no license plate in the back. When they open the trunk to get some tools, Collie finds a package of marijuana and arrests the couple, becoming insane and abusive, and the couple claims that they have stolen the car.
While driving to the jail of Desperation, the terrified couple sees corpses everywhere in the town; in the entrance of the police station, they see the body of a young girl, and the sheriff shoots and kills Peter. In the jail, Mary sees a couple and their religious son David Carver and an old local, Tom Billingsley.
Meanwhile the deranged sheriff arrests the successful and arrogant writer John Edward Marinville that is traveling in his motorcycle through the country promoting lectures. John gives a troubled and jammed call in his cellular to his assistant Steve Ames, who is following him in a support trunk with the hitchhiker Cynthia Smith.
When the group of survivors escapes from the jail and meets Steve and Cynthia, David discloses that one hundred and fifty years ago, a group of Chinese slaves released in the cave-in, an earth demon "waisin" called Tak, or the unformed heart. When the mine collapsed, all of them died, but something came out of the mine.
The group under the leadership of David and under the protection of God decides to battle against the pagan god Tak and get the world free of his evil.