Mauro and Roberto investigate the death of a young man who was hit by a car going at high speed and discover that he was involved in a clandestine car race. Meanwhile, Mauro's father, Tiberio, has been the victim of a financial scam, losing twenty thousand euros, half of which belonged to his son. Giulia calls an expert, Prof. De Santis, in search of the truth about the new discoveries related to her father's case. That evening, at the town hall, Paolo is waiting for her to finally celebrate their wedding. 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.