On Halloween night, Laura sneaks away from home to go to a party with her classmate Mireia. In a building with a disturbing past, they summon a murderous spirit. As the days go by, Laura has the strange and vivid visions that plague her, thinks that God is punishing her for performing a profane act. Is she going crazy? Must she somehow pay for her sins? Or is she possessed by the devil? After the strange behavior displayed by teenager Laura Villegas, her parents call an exorcist to intervene in the case of demonic possession. Father Olmedo is one of the 15 priests authorized by the Vatican to perform exorcisms in Spain.

This horror story set in the present day is inspired by a series of registered cases of exorcism in Spain. It was nominated for the Spanish Goya Film Award for Special Effects.