For France.

When World War I breaks out, young West Point cadet Gerald Ackland, who is studying in Paris, joins the French army as a fighter pilot. His French fiancee, Martha Landeau, and her father flee to the family farm, which is near the Marne River, for safety. When German troops take over the area, they raid Marthe's farm and attempt to ravage her--but suddenly, out of the sky, comes a French fighter plane that scatters the Germans--and its pilot is none other than Gerald. However, that's not the end of their troubles, by any means.