Acclaimed writer Jodorowsky puts a supernatural spin on one of the greatest myths in the history of France, The Man in the Iron Mask, rewritten as a grand, esoteric fable.The 18th century. In a monastery in the North of Spain hides the sacred temple of the Knights of Heliopolis: an assembly of immortal alchemists cut off from the world. As disciple Seventeen prepares to complete his training and integrate order, his master Fulcanelli reveals to the other knights the terrible secret of his origins – Seventeen is actually the hidden son of King Louis XVI and Marie-Antoinette!Wil the young heir remain in the shadows, faithful to the millennial precepts of Alchemy, or reveal himself and claim the throne?