Caliber 9 is a 1972 Italian crime film directed by Fernando Di Leo. The film follows Ugo Piazza, a recently released convict who is trying to start over in life. However, his past catches up with him when Rocco, his former employer, kidnaps him and believes Ugo has stolen $300,000 from him.
Despite Ugo's denials, Rocco and his gang torture him to try and force the information out of him. The police are also after Ugo, as they believe he has the money and are desperate to recover it. Ugo seeks refuge with his former lover, Nelly, but she too gets caught up in the violence surrounding him.
As the tension escalates, Ugo is forced to confront Rocco and his gang in a bloody finale that leaves few survivors. In the end, Ugo discovers the truth about the missing money and finds a way to escape his violent past once and for all.
The film is known for its gritty realism and graphic violence, and is considered one of the classics of the "poliziotteschi" genre of Italian crime films. It features a strong cast, including Gastone Moschin as Rocco, Barbara Bouchet as Nelly, and Mario Adorf as the police inspector hot on Ugo's trail.