Outside a Rome nightclub, a teenage boy dies in a car accident. Nothing suggests that this is anything more than a simple collision, but Corso, a former cop turned private detective, is convinced otherwise. Michelle, the mother of the young man and Corso's former mistress, is now the partner of Argento, a powerful and well-connected lawyer. During the investigation a body is discovered, that of an engineer who was apparently close to the lawyer. Bribery, wiretapping, espionage, a mob settling of accounts: he's dogged, but it won't be easy for Corso to get to the bottom of Michelle's son's death.