A social worker is killed in her garage and the prime suspect is her ex-partner who once beat her and who was at her house on the evening of the murder. He is not the culprit, but a dangerous man who was separated from his wife for this reason. Investigating the case, Muzo begins to deal with guilt over Olga's death.

A sportsman died from poisoning in the bed where he spent the night with one of his clients. Her suspicions focus on her, but the investigations soon lead to someone from her family circle. Marta went to Naples to follow a lead on the murder of her son without, however, saying anything to Carlo. He finds out and puts Cantabella on her tail.

The investigations focus on Nusco and whoever tried to kill him. Malik also has to follow the case of a student found dead in her home. During the investigations the policeman becomes fond of a child, to whom he makes a promise. Carlo is no longer able to live with the conflict of feelings he feels and confesses to Cristina that he has fallen in love with Marta.