In a faraway medieval realm, Manfred, an arrogant and evil prince, rules with an iron fist. Banishing his wife to the castle dungeon, he confines — and plans to wed — the lovely Isabella, fiancée of his recently deceased son. The prince's plans are foiled, however, when a well-meaning peasant helps the young woman escape through the castle's underground passages. Grisly, supernatural events further aid in fulfilling a prophecy that spells doom for the prince and justice for Isabella's rescuer and rightful heir to the throne.