Plot: The film follows a film crew that is documenting the operations of a "coyote" (human trafficker) near the border. They accompany him to a hidden tunnel for the pick-up of two illegal immigrants. When the tunnel is opened—acting as the titular "Devil's Door"—an ancient, malevolent evil escapes from within. This sinister force leaves a trail of blood and death, and the film crew is forced into a desperate, terrifying struggle to survive the escalating nightmare. The film is presented in a found-footage style.
