Four friends from a Cinema School in Lisbon, who play pranks to one another, they let a devilish entity be unleashed from a book of spells. In a certain weekend, when they go out to film in an isolated house in Portugal , one of them begins to show signs of being possessed, and they all begin to suspect one another. One by one they start being condemned by that unknown entity. But only one of them will resist to the devil and can be the key to the solution.