Mauro, is engaged in a difficult anti-drug operation. In the meantime, the wedding between Commissioner Giulia Corsi and Inspector Paolo Libero is about to be celebrated. Ardenzi is taken hostage by a bandit during the anti-drug operation.

Commissioner Corsi and Paolo Libero investigate a heroin trafficking inside a warehouse of slaughtered animals. In the meantime, Francesca gets back in touch with Ardenzi. Ingargiola buys a beautiful motorbike that, however, hides many dangers.

This time Mauro and Roberto are engaged in a desperate chase: a woman has kidnapped her eight-year-old daughter from school and, in a state of delirium, has involved her in a crazy car race to reach her husband's lover, whom she holds responsible for the failure of her marriage. Meanwhile, Parmesan discovers that his credit card has been cloned and that a lot of money has disappeared from his account.

After a tough confrontation with her sister Sabina, who until now was unaware of the reopening of the case concerning her father, Giulia decides to continue the investigation anyway, with the strong support of Paolo. Meanwhile, a pregnant woman who has just suffered a sexual assault arrives at the Decimo Tuscolano. All suspicions seem to fall on her ex-boyfriend, who, however, has an ironclad alibi.

Giulia asks her collaborators to solve the case concerning her father: Paolo and Luca identify a suspect. While Mauro and Roberto deal with their mutual problems regarding their private lives, a homeless man is found murdered in a park and the two agents immediately begin their search for the culprit.

Unexpected news reaches the Decimo Tuscolano. In fact, while Roberto, happy about some sentimental news, receives the official transfer letter, Mauro discovers that a friend of his, an aspiring boxer, is in a coma in the hospital after being violently beaten. The agents understand that the victim is involved in a clandestine betting ring and Paolo, who has years of kickboxing training behind him, offers to go, as an infiltrator, to the gym frequented by the beaten boy.