On the night before his retirement, police lieutenant Franco Amore is called to investigate the death of a long-time partner of his in a diamond heist in which he was involved.

Milan, Italy, 1967. Santo Russo, a boy of Calabrian origin, arrives north with his parents and younger brother to find better living conditions. Due to an absurd misunderstanding and his father's contempt, Santo ends up in prison, where he gets a “true education.” In 1978, he and his friends Slim and Mario embark on a 15-year criminal career, a successful and ruthless spiral of robberies, kidnappings, murders and heroin smuggling.