Abandoned unconscious by Dorian in the beach house in Ostia, Inspector Gori is rescued by her colleagues. Upon awakening from a concussion, the woman discovers on her body a mysterious tattoo given to her by Dorian. While the inspectors are looking for the lighter with the mole's prints lost by Gori on the beach in Ostia, Commissioner Benvenuti becomes convinced that the mole is the magistrate Castelli.