A lone robber, riding a maxi scooter that is different each time, robs one bank and one jewelry store after another by darting at great speed through the folds of Rome, among its ancient beauties and urban archaeologies, always managing to lose his pursuers and finally vanish into thin air. The case is in the hands of a veracious and cynical Roman commissioner who, unable to get to the bottom of it, seeks help from his Parisian friend, known as the Frenchman, a former commissioner famous for his psychological insight and for having solved dozens of impossible cases. All except the one involving the death of his daughter, for whose anniversary he returns to the city every year. It will be he who discovers the identity of the robber, a person as unsuspected as he is of great intelligence, with whom he engages in a challenge of unpredictable consequences. (Source: Official Italian synopsis translated via DeepL)