It's been 40 years since the St. Francis Boarding School for Girls was shut down after a horrific tragedy occurred there. The ghostly structure remains boarded-up and condemned; the source for many an urban legend. In what has become an unspoken tradition, a group of college students break into the dilapidated building. When the police arrive, one of the students, Mo, stays behind to avoid trouble. She becomes the unfortunate hostage of a group of Satanists who use The Convent as a place of devil worship. When Mo doesn't come to class the next day, her friends return to find her. No one is prepared for what happens next. An evil spirit possesses Mo's young body. All exits become impenetrably blocked and the prisoners find themselves on a terrifying roller coaster ride, battling demons and struggling to avoid possession. What happened there 40 years ago? And who, if anyone, will survive this time?