The son of the PM Menale mysteriously disappears and the team suspects a criminal sentenced by the magistrate, who has just escaped from prison. In the meantime, at the foot of an abandoned farmhouse, the body of a girl with traces of lethal chemical substances is found: with the help of Dr. Salibra, the men of Sant' Andrea try to understand what happened. Pettenella takes over the management of the police station in the absence of Cafasso, who left for the East. After a night with Berti, Anna is in internal conflict and decides to follow her instinct.