Robert Stack says in his biography that Jean Gabin - whom he called the French Spencer Tracy - was a person very pleasant to work with. Their relationship was very good. But Robert Stack also admitted have spent the Christmas Eve, alone, far from his family, because of the shooting, at Hotel George V in Paris.
In Melodie En Sous Sol, made four years earlier, Jean Gabin also played an old gangster pulling his last heist where his accomplice permitted him to get into a vault from the outside. Here, Robert Stack is the accomplice and Alain Delon was the one in Melodie En Sous Sol.
In this movie, besides the heist scheme, Gabin plays a owner who has to fight against drug traffic goons who use his restaurant to deal heroine. The nearly same scheme as La Horse, the movie which he will play in two years later, and where he will be a big farm owner where drug pushers will also hide heroine.
Final film of Micheline Sandrel.