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 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. Cast Production Caliber 9 was Di Leo's second film to be based on the works of writer Giorgio Scerbanenco, following Naked Violence (1969). According to film historian Roberto Curti, the director saw Scerbanenco's works as "ground-breaking", and believed that they shared similarly "bleak, disillusioned" worldviews, noting that the writer would have enjoyed the film's "terrible yet bitterly ironic game of appearances, coincidences and double-crosses which moves the story to its inevitable conclusion". Credited as being based on Scerbanenco's 1969 short story collection Milano calibro 9, the script is largely an original work, although it was partially influenced by three of the book's stories: its depiction of an exchange of two packages between a series of couriers, culminating in both packages simultaneously exploding upon reaching their final destination, is taken from "Stazione centrale