[4] In the winter of 1943, a group of resistance fighters, led by the "engineer" and including Rodolfo, Oscar and Danilo, manage to detonate a charge at the Kommandantur in Venice.

Faced with the Germans' threat to shoot the hostages, the Committee decided to call on the Archbishop to intervene and put a temporary halt to the attacks carried out by the "engineer".

The other three committee members, Christian Democrat "Nemo", Action Party representative "Smith" and Communist "Piero", are hidden by Ugo in his clinic.

Oscar is arrested in his turn, and as he is taken away on a boat, his interrogator tells him that he knows the exact identity of the "engineer" perfectly well: he is an assistant professor of physics at Padua University by the name of Renato Braschi.

The next day, the operation to escape from Venice to the mainland is launched, but fails because the Germans and Fascists knew about it: Renato was shot and the three political leaders hiding in the clinic were captured.