Rocca investigates the murder of his homeless friend Alberto Molfetta, who was set on fire. During the investigation, a father accuses himself of the crime to cover up for his son, but Rocca, deeming him innocent, discovers the real culprits. Once the case has been resolved, the marshal pays homage to his dead friend by fulfilling his last wish: a concert with Molfetta's voice spread throughout the square.

Shortly before Rocca and Margherita's wedding, the woman's ex-husband reappears and will be found dead the next morning, together with a fragment of Margherita's dress. The wedding postponed, Margherita is accused of the crime, but, convinced of her innocence, Rocca investigates to find the real killers.

Found the body of a transvestite in the swimming pool of a health club, the most accredited hypothesis is that of a heart attack. Rocca, not believing this version, gives up his honeymoon with Margherita to find out the truth. The investigations prove the marshal right, revealing family intrigues and a homosexual relationship between the victim and his killer.

The rebus found on a note at the bottom of Rosa Bastiani's throat, a mother of a few months old baby stabbed in a park, kicks off complex and painful investigations, which will put Rocca and his colleagues to the test. Everything will become more difficult when one of the sisters of Carabiniere Banti will be involved. The marshal, putting his life at risk, will investigate Professor Aleppi, headmaster of the school, discovering a past made up of injustices, traumas and suffering. Once the case is resolved, Rocca and Margherita obtain custody of Bastiani's orphan.