A prominent writer is found dead in the Villa Torrini outside of Florence without any marks of physical harm on her. Her husband, who was heavily intoxicated in the next room, is exhibiting signs of guilt, but the carabinieri are having trouble finding concrete evidence against him. Marshal Guarnaccia, who is already struggling with a strict diet and the intricacies of a new legal system, has little faith in his own ability to solve the case, but his intuition turns out to be invaluable.
