When a mobster is assassinated in Naples by the gangsters of Gennaro Gallo, the retired hit-man Peter Marciani learns that Gallo was the responsible for the murder of his brother. He travels from New York to Italy to revenge his brother and he hires the smalltime crook Angelo to work for him. Angelo introduces Peter to the dancer Anny and they have a love affair. Meanwhile the Italian police inspector unsuccessfully tries to anticipate Peter's move.