Wrongfully imprisoned in a Mexican jail, outlaw-with-a-conscience Jess Galvan accepts a devil's bargain: transport a sinister package across the border for the jail's mythical—and terrifying—bogeyman El Cucuy. If Jess can survive and deliver the iron box in twenty-four hours, he will be free.

But as Jess navigates the deadly desert, girls go missing and bodies begin to surface—an epidemic of crime that plunges small-town sheriff Bob Nichols into a monstrous investigation. For an ancient evil has awoken in the wastelands and quickly epic myth and human malice threaten the end of the world.