The intuition of the new commissioner of the X Tuscolano Roberto is not wrong: behind the apparently casual death of the model Eva Paulin there is something more. The young woman, with the complicity of her brother Milo, stole precious objects from her rich clients. Milo has the commissioner receive a notebook that Eva had kept, before dying before his eyes. Meanwhile Mauro and Irene deal with the disappearance of little Marcello. The first suspect is the father, divorced for years, who had no right to see his son, but the story presents even more disturbing implications.