A Canadian archaeological team, led by Professor Evans, descends on the ruins of a medieval Sicilian monastery to undertake an excavation. However, when Evans’ protégé, Liza, searches for an explanation to the disturbing visions she’s been experiencing, she awakens the spirits of three Satan-worshiping nuns who were put to death centuries earlier by a violent mob, unleashing an orgy of vengeful violence on the unsuspecting explorers.