Coliandro gets involved in a bank robbery in the center of Bologna. The three robbers, young and inexperienced, are soon rendered harmless by three hostages, who, in turn, take the other people hostage.

During a nocturnal chase in the streets of Bologna, a girl steals his gun from Coliandro. While trying to track down the unknown, the inspector comes across a dangerous criminal organization.

Two gypsy girls steal something very important from the house of the wrong person, a corrupt marshal of the carabinieri, who, with an ambush, tries to take revenge. Thus, one of the girls takes refuge in Coliandro's house in search of help.

On the estate of a very wealthy man, an escort is cruelly murdered at the hands of a cold and determined assassin. The investigations lead Coliandro to confront the world of high class prostitution.