A young woman who comes to Rome and soon drifts into de facto prostitution in order to survive. She meets a misanthropic doctor and would-be poet, but soon falls in love with another man. Murder ensues and she soon finds herself being blackmailed, sexually and financially, by her husband's shady driver, who saw something he shouldn't have.

Nick Hezard, a young con man, wants to avenge the death of a friend of his and organizes a swindle trying to cheat Robert Turner, an American businessman he thinks responsible for his friend's death. He succeeds in getting a hundred thousand swiss francs and uses them to carry out the second part of his plan.

The city of Turin is in the grip of a brutal crime boss known as "Il Marsigliese" and plenty of cops have good cause to want him dead — none more than Inspector Vanni, whose wife was murdered by the ruthless gangster. Having exhausted every other avenue, Vanni forms a crack squad of motorcycle-riding, Colt .38-toting elite officers, tasked with meting out justice on the margins of the law. But when "Il Marsigliese" launches a bombing campaign designed to extort a vast ransom from the city's authorities, Vanni finds himself in a race against time to exact his revenge and avert disaster.