A troubled couple and their blind daughter come to Italy to visit a 12th Century castle they've inherited. Soon they are plagued by unexplained noises| mysteriously
broken objects| and the daughter's claims of an unknown nocturnal visitor to her bedroom. When the housekeeper and a local prostitute and are discovered savagely
murdered in the castle's dungeon| John must unlock the castle's secret to save himself from jail and his family from the castle's secret inhabitant.