The King of France has twin daughters: Madeleine, well mannered and virginal; and Jaqueline, perverse and sexually obsessed. Before leaving on a sea voyage, he locks the wayward Jaqueline in the tower, her to wear an iron mask. Later, however, the royal ship is attacked by pirates and Francois, Madeleine's fiancee, is dispatched to search for the missing King. Meanwhile, Jaqueline uses her erotic charms on her guard, Maximillian, convincing him to help her escape. She takes the place of Madelein...