When Madeleine took on her father's mission, she did not expect to have to face a supernatural power. The prophecy was right and the Salon-de-Provence castle is the scene of atrocious carnage. Jean-Aimé de Chavigny's refusal to cooperate makes him a prime suspect in the murders. The queen's handmaiden Constance is also a suspect, while Philibert's mysterious research takes on new meaning. This is the last part of a three-part adventure.