Georges De Meyst wrote for the  underground press, and in July 1944 he came up with the idea of  shooting in secret a fiction film about the Resistance. By  pretending to make cultural documentaries he built up a stockpile of  film and he and Herdé, René (qv) (who was to play the leader of  the network) then concocted a script about the evil deeds of drug  traffickers. Caution was indeed called for, since the sound engineer  turned out to be an infamous collaborator. Shooting began during the  final weeks of the Occupation with most actors believing they were  playing in a crime movie. The Liberation of Brussels afforded the  opportunity to shoot the uniformed sequences and De Meyst rapidly  completed what was to be the first feature film on the Resistance.