While maintaining order at the city stadium, Coliandro and Officer Balboni arrest a football fan who had tried to stab a policeman. Terrified by the thought of ending up in prison, the boy cooperates and provides the police with some important information.

Officer Gargiulo shows up at Coliandro's house in the middle of the night, drunk and with a bloody knife in his hand: the inspector tries to reconstruct what happened, but it doesn't seem easy.

The husband of a former professor from Coliandro is murdered inside the University of Bologna. The woman is accused of the murder because of her husband's constant escapades: could this really be true?

A young Muslim girl shows up at Coliandro's office to report her father's sudden and mysterious disappearance. Reluctantly, the inspector nevertheless decides to investigate the matter around town.

In the trial against the Casalesi clan boss, the Bologna prosecutor's office must rely on the testimony of Jelena, who is now under protection. Coliandro, still in love with the woman, learns of her new cover and decides to visit her. There, however, he must contend with two seasoned killers.

As punishment, Coliandro has been transferred again, this time to the tedious canine unit. His sister comes to visit him, deeply concerned about her daughter Angelica, who is dating a boy associated with a satanic cult.

Kayo, a young Japanese doctoral student in art history, unwittingly witnesses a ruthless execution. She accidentally encounters Coliandro, who decides to protect her and hide her in his home with his brother Kenzaburo. Kenzaburo, who came from Japan to protect his sister, is a former yakuza informer, a fearsome Japanese mafia who is hunting them.

Coliandro seems on the verge of a successful conclusion to his romantic adventure. But, just as things are going, Giacomino shows up at his house, sleepy, hungry, and handcuffed. The motive is incredible: Giacomino is accused of committing a series of brutal murders. To help his friend, Coliandro must hunt down the real serial killer.

Coliandro is forced to be Paffoni's dance partner for an evening. To escape this unpleasant task, he finds himself investigating the murder of a young singer. He's helped not only by Paffoni, a skilled dancer, but also by Natascia, the young and beautiful new singer in the liscio orchestra led by the shady Vasinto and his wife Ersilia, known as "Vagona."

At the police station, Coliandro meets Asmareth, a young and beautiful Eritrean cultural mediator who works for the police. Believing her to be an illegal immigrant, Coliandro makes one blunder after another. To gain forgiveness, he agrees to help her with an investigation she's conducting into illegal work. Coliandro and Asmareth thus expose a gang organizing "manhunts" for bored, wealthy provincials.