This is an unusual war film for several reasons. The story centers on a group of Nazi submariners who are attacking ships in the North Atlantic when their vessel is sunk off the coast of Canada. The surviving crew—headed by Eric Portman in a strange role—seizes control of a Hudson's Bay Company trading post, which is normally visited by Laurence Olivier, who is French-Canadian, and Finlay Currie, a stern Scottish man unwilling to accept this "invasion." From there, a somewhat disjointed collection of episodes unfolds, showing their efforts to return home using almost every mode of transportation imaginable, except for a hot air balloon. The latter portion of the film moves along more quickly, featuring a restrained performance by Leslie Howard as the survivors get closer to their destination, suggesting that words can be more powerful than weapons before they have a final confrontation with Raymond Massey. The team working behind the camera is also impressive; Freddie Young and David Lean (as editor) collaborated on Emeric Pressburger's story, guided by Michael Powell’s direction, to capture the beauty of the Canadian landscape—its lighting, colors, and well-written dialogue—which feels far less simplistic than some earlier films that served a propaganda purpose.

Source on TMDB