Rome is on the thresh-hold of the Holy year 1925, the city wishes to present itself as 'spotless' to the outside world. The appearance of a child's corpse puts an end to these aspirations. The police arrest a small time crook who has committed a robbery but has nothing to do with the murder of the child. His 'fence' the jeweler BALETTA, who is also a member of the ruling political party, suggests a deal: the crook goes free and in return Barlett will spill the beans on a planned robbery of the treasury in the Vatican. The police agree to the deal, and soon after one of Barletts contacts is found dead. The police send officer Guglielmo Motta, who is not known in Rome, under cover as a wealthy 'fence' ( dealer in stolen goods). He slips into the criminal milieu thanks to the helpful charms of the lovely Lulu- they fall in love. Guglielmo gets scared when the body of Barlett shows up, and Lulu treats him with a new coldness. He wants out! The police chief dismisses this request. To top ...