Giovanna Scalise, Isabella Ferrari, a police commissioner, is transferred from Sicily to Rome for security reasons, where she is assigned command of a police precinct. Scalise's transfer isn't easy: the commissioner is forced to hide from her men the fact that she will be testifying at the mega-trial against her husband's murderers.

In the second season, Giovanna begins a new romance with Inspector Walter Manrico, while Carmine Tonnara, Don Vito's son, dies in prison. The Tonnara family, after the Maxi Trial, has been dismantled. The only one still at large is Mafia boss Vito Tonnara, who, blinded by revenge, tries everything he can to eliminate Commissioner Scalise.

The third season opens with a surprising twist: the arrival of the new Commissioner Giulia Corsi at the Tenth Tuscolano District. She must deal with the legacy of her father, a magistrate murdered a few years earlier, and investigate the murder of Angela Rivalta, Inspector Ardenzi's wife.

In this gripping fourth season, Commissioner Giulia Corsi will have to deal with her father's murderers, who will do everything they can to stop the agents of the Tuscolano Tenth in their investigation, hitting the Commissioner where she is most dear.

In this fifth season, a new elite officer, Anna Gori, arrives at Precinct X Tuscolano, where she will team up with Luca Benvenuto. Meanwhile, a Carabinieri captain, Davide Rea, played by Giampaolo Morelli, tries to gain the trust of Commissioner Corsi and investigates the shooting that left Inspector Belli's wife, Germana Mori, injured and in a coma.