In August 1944, Gestapo attacked the Vaillance network's headquarters and their leader Castille was killed. 15 years later, one of its member, Marie-Octobre (Danielle Darrieux), meets an ex-German soldier who tells her that one of her friends had betrayed them. Helped by Renaud-Picart (Paul Meurisse), Marie-Octobre invites the ex-Vaillance members to the ex-HQ to find the traitor.
"We may not be 13, but there is Judas Iscariot among us."
Except the opening scene which shows the road to the castle (HQ) and the façade, all the scenes are shot in one big room. It's like watching a play on stage. All the actors are excellent. The idea to gather all characters reminds me of Agatha Christie's And Then There Were None at first, but the murder they are trying to solve is a murder happened 15 years ago. Did Gestapo kill Castille? Each of them, who after 15 years are successful in their jobs, tries to remember what really happened. Interesting, because it's now clear that Simoneau (Bernard Blier) is the most disliked, but doesn't mean that it's him who killed their leader. I actually prefer the movie ends when Victorine tells her story, because it would be funny if after all the efforts, it turns out the Gestapo found out about the network because of a blunder. However it doesn't, and they finally find the traitor who confesses he killed Castille in cold blood. It's a crime of passion and greed.