There are two things about THE MORTAL STORM that make it unusual. First, it comes from MGM, primarily known as the studio that produced glossy technicolor musicals. Secondly, the entire cast have roles that are unusual for their persona.
Take, for example, all American Robert Young and Robert Stack as dedicated Nazis. Or Frank Morgan as a German professor in a highly dramatic role. Or Bonita Granville in one of her first near-adult dramatic roles. Or Dan Dailey before he became known principally as a musical star. Like several other films of this period (Escape, Nazi Agent, To Be Or Not To Be, The Great Dictator, Berlin Correspondent), it treats the subject of the approaching storm of Nazism with both conviction and emotional power.
Tension builds once it becomes apparent that Margaret Sullavan (as Morgan's daughter) and James Stewart must leave their homeland to escape the Nazi menace that has slowly penetrated their village. The finale with the ski scenes of the two escaping down a mountain slope is played for maximum suspense as they flee to freedom in Austria.
Produced on a handsome scale with realistic looking winter locations and featuring splendid performances from Margaret Sullavan, James Stewart, Robert Young, Frank Morgan, Robert Stack, Bonita Granville and Maria Ouspenskaya, it is guaranteed to keep you absorbed until the very end.
Margaret Sullavan and James Stewart give their usual earnest performances but it's the superior script and Frank Borzage's expert direction that really counts here. Well worth viewing.