After a stint in prison, small-time Milanese gangster Ugo Piazza is immediately harassed by his old associates, led by a powerful American launderer known simply as The Americano, who believes he stole 300,000 US dollars during a handover shortly before his arrest for robbery. Piazza emphatically denies the theft, even under coercion from The Americano's volatile right-hand man Rocco. His girlfriend, go-go dancer Nelly Bordon, also believes he stole the money, as does the police commissario, who unsuccessfully attempts to turn him informant.
Piazza meets his former godfather, Don Vincenzo, now a blind old man, and his sole remaining capo Chino. Though Rocco mocks Vincenzo's authority, they still hold a begrudging respect for Chino, who has refused to leave his godfather even after everyone else has. The Americano gives Piazza an ultimatum to return the money and resume working for him, but he still insists he doesn't have it and doesn't know who does. Paranoid about more, similar thefts, Rocco begins killing off his money couriers.
Piazza is sent on an exchange of $30,000, happening in a bowling alley. The exchange is crashed by a mysterious assailant in a white scarf (who has been stalking Piazza since his release), who kills their client and steals the brown leather bag containing the money. The Americano sends Rocco and Piazza to kill the men he believes responsible, but when they arrive they're revealed to be Chino and Don Vincenzo. Piazza refuses to slay his former godfather, but Rocco coldly shoots the old man, while Chino narrowly escapes. The Americano has Piazza beaten for his insubordination and is about to have him killed. However, Piazza’s is spared when he convincingly argues that Rocco and the crew were behind the theft of the $30,000.
The Americano retreats to a rural estate with his bodyguards, including Piazza, but is shot and killed in an ambush by a vengeful Chino. Piazza turns his gun on the Americano's men and finishes them off, before Chino dies of his injuries.
Piazza travels to an abandoned church off Milan and retrieves a blue bag with the $300,000—revealing he had stolen the money from the Americano years ago and orchestrated everything to get him killed. However, he's picked up by police for driving with an expired license and forced to go to the station for an interview.
While in the waiting room, Piazza runs into Rocco (who's being questioned for the shootout at the Americano's house). Rocco, seeing the bag containing the money, shows no animosity and offers the two become partners. Piazza turns him down and is released. He heads to Nelly's house with the money, planning for the two to run away together. Nelly is with Luca, one of Rocco’s crew and the man in the scarf who was behind the theft of the $30,000 at the bowling alley. Nelly had conspired with her secret lover Lucato to get the $300,000 from Piazza for themselves.
Luca shoots Piazza, but he manages to kill Nelly with a single punch before expiring. Rocco, who had followed Piazza home, bursts in and beats Luca to death in a fit of rage for his betrayal and disrespecting of Piazza's criminal stature. The police, who had in turn followed Rocco, drag him away from Luca’s bloodied corpse.
