Following the defeat of the world revolution, and the counter-revolutionary seizure of power by Stalinism in the USSR, the priority for the tiny internationalist groups that had survived the disaster was to understand the reasons for the defeat. This also meant understanding what a real transition to communism, and to some extent communist society itself, would look like. In these articles - which begin with a summary of the main ideas contained in the previous articles of the series - we concentrate on the efforts of the Italian Left in exile (around the Bilan group), and the Dutch and French Communist Lefts, during the dark years that before, during, and after World War II.