Bátky János a 20th century intellectual studies the secret of the Rosicrucians in London libraries during the day and in the evening takes pleasure in the "decent" everyday joys offered by the fair sex. He gets involved in the wildest ghost-story in the mysterious Wales castle of the Pendragons, where Earl of Gwynnedd from the 18th century is making experiments to prove his ancestors' slogan, "the resurrection of the body". In the meantime St. Claire, a beautiful, demonic woman and her companions try to kill him for the huge legacy.