Based on a novel by Jacques Robert, Julien Duvivier, Henri Jeanson and the author himself, wrote an original script for this film, which actually looks more like a play, as everything happens in the space of a few hours, and almost always in the same room.
The plot, despite focusing on the discovery of a traitor, among the group of old comrades in arms, of the resistance, almost seems like a long scene from Agatha Christie, in which Hercule Poirot unfolds hypothesis after hypothesis, until concluding with the discovery of the murderer.
The main attraction of the film is that it allows us to read between the lines of the police plot, to show a France that is both resistant and collaborative. They are all suspects because, despite being heroes of the resistance, they all collaborated, more or less, with the German invader and the Vichy government. And everyone accuses each other of these civic sins.
It is France settling accounts with history and clearing its guilty conscience of defeat and collaborationism, during the Nazi occupation.
In this sense, it is a provocative work, for its time. But subtly reading.
However, in general, it looks almost like a banal Cluedo game, despite a cast full of stars.