Just out of prison, ex-con Ugo Piazza meets his former employer, a psychopathic gangster Rocco who enjoys sick violence and torture. Both the gangsters and the police believe Ugo has hidden $300,000 that should have gone to an American drug syndicate boss. Caliber 9 is the first part in Di Leo's "Milieu" Trilogy of poliziotteschi films. It was followed by "The Italian Connection" (1972) and "The Boss" (1973).
When a shipment of heroin disappears between Italy and New York, a small-time pimp in Milan is framed for the theft. Two professional hitmen are dispatched from New York to find him, but the real thieves want to get rid of him before the New York killers get to him to eliminate any chance of them finding out he's the wrong man.
After a nuclear holocaust, as the rest of society regresses to primitivism, a small, "elite" group that has managed to escape radioactive contamination takes it upon itself to exterminate those it sees as "unfit", including certain members of its own group.
