group of ex-resistance fighters are brought together by Marie-Octobre, the code name of Marie-Helene Dumoulin (Danielle Darrieux). The former members of the network have carried on with their lives after the war, but this evening they are going to have to live again a fateful night – the night their leader was killed. He had been betrayed, his name given to the Germans. The search for the traitor puts each personality in the spotlight – and also that of the killed leader, Castille.

Overview from themoviedb.org