In the medieval castle of Talwar, whose owner is the high-born Sir Justin Baldwin, a love drama is playing out. Fragile, lovely Isabel, the beloved wife of the handsome Justin, is unable to resist the machinations of her hard-hearted cousin Evelina. At the cost of blood, she seeks to take possession of the soul and body, and most of all, the property of the simple-minded knight Justin, and it seems that luck is about to smile on her... But is it possible for evil to triumph over good?..