After an anonymous phone call, a teenage girl is found hanged in the attic of an old building in Lombardia and the police assume she committed suicide. The efficient Insp. Silvestri and the newcomer Asst. DA Vittoria Stori assume the case and while checking the location, Insp. Silvestri sees a middle age man, Bruno Paglia, taking pictures of the place from a nearby building. The man is arrested and soon Insp. Silvestri learns that the 14-year-old victim, Silvia Polvesi, was part of a teenage prostitution ring, including the beloved daughter of Insp. Valentini. His further investigation with the Asst. DA Stori discover a tape where sexual encounters with important names in the Italian society are recorded. Meanwhile a motorcycle rider wearing black uses a cleaver to get rid of suspects and witnesses.