The Nun (2006)

Synopsis: A wicked woman of God who mysteriously vanished decades ago reaches out from the underworld to unleash holy hell on the terrified group of former boarding-school students she tormented in life in director Luis de la Madrid's horrific tale of ultimate evil. It was many years ago that a sadistic sister pushed a group of frightened young students to their breaking point, but in the years after her unexplained disappearance, the specter of her evil still looms heavily in the hearts and minds of the children who once incurred her wrath. Now, as the grown alumnae fall prey to a murderous supernatural force, the time has come to bury the past and send the spirit of evil screaming into the pits of hell.     Source: RottenTomatoes.com