During World War II, two French civilians and a downed British Bomber Crew set out from Paris to cross the demarcation line between Nazi-occupied Northern France and the South. From there they will be able to escape to England. First, they must avoid German troops – and the consequences of their own blunders.

Once upon a time there lived in the same village two men bearing the very same name. One of them chanced to possess four horses, the other had only one horse, so, by way of distinguishing them from each other, the proprietor of four horses was called "Great Claus," and he who owned but one horse was known as "Little Claus"...

Thanks to a bit of string-pulling by his aunt, Jean du Bois d'Ombelles, a young recruit who has blue blood in his veins, hopes to go through a nice and comfortable military service. Unfortunately he becomes Corporal Bourrache's pet aversion. Nevertheless, against all expectations, Jean ends up taking a liking for military life.

A little boy won't go to the bathroom, which leads to all sorts of complications for his parents and their friends.