It is a detective movie in which the main scene is a chase along a flight of steps which, from Piazza di Spagna in Rome, leads to the church of the Trinità dei Monti. It is one of the most famous places of our capital in the world and the most visited by tourists, an incomparable urban scenography. In the movie there are three cars chasing each other: a PORSCHE, an ALFA ROMEO GIULIA, a CITROËN DS and a FERRARI 250 GTE; the latter, called "Ferrari della Polizia" par excellence, was involved in the fight against crime in Rome by marshal Spatafora and it entered service in 1962, occupying the scenes and the chronicles throughout the 1960s. The Alfa Romeo Giulia (1962) was produced by the Milanese company from 1962 to 1977; it was the evolution of the "Giulietta", and it has been proposed in many bodywork variants: sedan, coupé, convertible and spider. This fast and resistant car was really supplied to the Flying Squad of the State Police, to the Carabinieri of the Radio Division and to other Italian Police Forces. The Citroen DS (1955-1975) was a snappy, aerodynamic car with innovative devices. It was very appreciated by the French filmmakers of the Nouvelle Vague.