Manfred, the lord of the castle of Otranto, has long lived in dread of an ancient prophecy: it's foretold that when his family line ends, the true owner of the castle will appear and claim it. In a desperate bid to keep the castle, Manfred plans to coerce a young woman named Isabella into marrying him. Isabella refuses to yield to Manfred's reprehensible plan. But once she escapes into the depths of the castle, it becomes clear that Manfred...