Switzerland 1523. The mercenary Hansli Gyr returns with his soldiers from Italy to his home in the Oberland. They have fought for the Pope and now find a religious upheaval in Switzerland.

Five people have stolen a priceless, legendary emerald from a religious temple. One of them is slain by an unknown killer.

The titular Marie-Louise is a young French lass who is evacuated to Switzerland when her country is overrun by the Nazis. Suffering a nervous breakdown, she is given comfort and shelter by a wealthy family. Unfortunately, living in the lap of luxury makes Marie-Louise hesitant to return home to her mother and war torn home. Eventually the girl comes to her senses, but it isn't easy.