In April of 2010, Spanish police reported the discovery of 37 hours of recorded evidence that shed new light on a gruesome murder investigation. The found footage documents a family of five spending their holidays at their summer house, where brother-and-sister Cristian and July Quintanilla pass the time investigating a terrifying local urban legend. As their investigation intensifies, strange occurrences in and around the house escalate rapidly, before culminating in unspeakable atrocities.