Secret Mission

Secret Mission is a 1942 British war film directed by Harold French and starring Hugh Williams, James Mason, Nancy Price, Carla Lehmann and Roland Culver.

As part of the mission, Garnett and Gowan masquerade as champagne salesmen, aided by a personal letter from Ribbentrop. Having thus established their bona fides, they do deals with German officers for supplying their mess. They also extract much information from the unwary Germans. They also discover that a local businessman, M. Fayolle, hated by some of the locals for his open collaboration with the occupying forces, is in fact secretly working with the French resistance and has assisted many Allied servicemen to escape.The agents manage to gain access to a secret factory, which is so well disguised that it cannot be bombed, and show a light for arriving paratroopers, who land and overrun the factory. However, Raoul is killed. ........

Source: Wikipedia