After the death of his wife, inspector Monaco seems uninterested and tired of his work. Refusing to return to the streets he spends the days behind a desk at the office, checking documents, photographs looking for evidence, just to avoid human contact. One night the murder of a rich entrepreneur Mr Ullrich, forces him back on the streets. He finds himself facing his own daughter Linda, arrested for possessing a gun and suspected to be implicated in the case. As a policeman and as a father, he decides to take part on the investigation along with Levi, his colleague and friend. It will be a long night of revelations and discoveries.