Lojacono and Di Nardo go to see Biagio's ex-girlfriend to ask her one more question. She happens to remember something that gives them a new lead. They then go and talk to Renato, Biagio's friend and colleague.

Lojacono is confident he knows how the murder happened and is able to trick Renato into saying something he couldn't have heard on the news.

The case has been solved, one gets the feeling that if the murderer had been Varricchio, a common ex-convict, instead of a promising biologist, son of a prominent professor, the outcome would have been more palatable to the city and to the press.