In French underworld, 'doulos' means 'hat' and the person who wears it is 'an informer'. Therefore, in English the title is translated as 'The Finger Man', which I think refers to Jean-Paul Belmondo's character, Silien. From the beginning of the movie, we are led to believe that Silien cannot be trusted. At first I also wondered about this, because in movies by Jean-Pierre Melville there is always honour among thieves, and that betrayal is the greatest sin.
The film starts by introducing us to Serge Reggiani's character, Faugel, who is recently out of prison. Faugel visits his fence, kills him, and takes the jewelry, money, the revolver and bury them. He has his girlfriend Therese to watch over a big house for their next job. On the D-day he asks Silien to bring over the tools, and go with Remy. The police come and Remy is killed, while Faugel himself is wounded. His friend Jean hides him, but thanks to Silien, the police can find Faugel and jail him.
The movie features 8 minutes scene shot in one take, when the police interrogate Silien. Melville was so proud of this scene, a proof that he could do it. After watching 4 of his works, where usually the story flows like water, I didn't expect any twist in Le Doulos. When Silien first tells his story, I was considering if he was telling the truth or not. I like the ending, that Silien takes time to look into the mirror, tidy his hair, and straighten his hat; before collapsing.