In South America anything can happen: the consul might give you as a snack to the sharks, you can wind up as a working man (slave) in a banana plantation or as a recruit in the governor's navy. And there's always a fire squad waiting for you so you 'd better start a revolution! It takes all Fernandel's talent to go through this eventful journey.

Mr. Pelletan's rascal son Bébert son got another F for playing in class. His punishment is an essay on the Merovingian king Dagobert. All they know is he had eight wives and reunited Francia. The ignorant knave's irreverent imagination turns that into a harem and a ludicrous war without armies, loaded with anachronisms, in a race against rival king Charibert for the crown of Reims. The king's right hand, archbishop Eloi, the later patrons saint of carpentry, is portrayed as an inventor.

Assola is an imaginary village on the border between Italy and France and the borderline crosses the village itself. The French customs agent Ferdinand is always trying to catch the Italian smuggler Giuseppe. Giuseppe discovers that Ferdinand was actually born in Italy and therefore he can't be a French customs agent.