When a crime boss sends out his thugs to terrorize an entire city, they do whatever they want, which includes anything from petty theft to robbing the police station in broad daylight. Napoli spara! (internationally released as Weapons of Death and Naples shoots) is a "poliziottesco" film directed by Mario Caiano in 1977. It is an unofficial sequel of Napoli violenta, of which reprises the character of Gennarino (still played by Massimo Deda).

Hoping to overthrow his brother as ruler of the planet Metropolis, the evil Graal enlists the help of the insane Dr. Kraspin, who has invented a chemical capable of turning an ordinary person into a perfect soldier. They test this chemical on the pilot Golob, turning the unsuspecting victim into a mindless but indestructible automaton possessing superhuman strength. The people of Metropolis must somehow outwit Graal before he can create an army of these soldiers, or their planet will be destroyed.

An Italian reporter is travelling on the Instabul-Athens train. A woman is murdered with the reporter's letter-opener so that makes him the main suspect. With the help of his Swedish girlfriend he starts investigating in order to prove his innocence.