A man in a deep depression kills his wife and her new partner. The daughter, who learns of the tragedy on the news, turns to the Decimo Tuscolano, who immediately offers her protection. Soon, however, the girl's father will try to track her down. Ugo and Ingargiola, meanwhile, investigate the disappearance of two elderly ladies. Paolo notices that Sabina, Giulia's sister, is in crisis over what has been discovered about her father and decides to get to the bottom of the research. He discovers some details that will prove very risky for him.