Against The Wind [1948]

Philip Elliot, a refugee Belgian priest, reports to a secret school in London for spies and saboteurs behind German lines. After training, he and two others parachute into Belgium to help destroy a records office. This mission leads to German capture of an important resistance leader, and four more agents (Emile, Max, Scotty, and Michele) go in on a rescue mission. But one of them is a traitor; and other things go wrong.