Sean Connery and Christian Slater play Fransiscan monks who arrive at a monestary, where they discover one of the young monks has recently died. The Abbot believes Satan is possessing the monks. When another monk is killed, Sean Connery and Christian Slater begin an investigation into the deaths. A third monk is killed and Sean Connery realizes that the two most recent monks both had a black stain on their forefingers and on thier tounges. He links their deaths to a mysterious Greek book. The Abbot is very worried and calls for the Inquisitors to come and rid the monestary of evil. In the meanwhile, Christian Slater has *fun* with a peasant girl and falls in love with her. When the Inquisitors arrive, two more monks are killed. The girl, the hunchback, and one of the monks are tortured and sentenced to be burned at the stake.