Life in Gestapo jails in occupied Belgium.

A band of traffickers seeks to infiltrate among smugglers on the Franco-Belgian border. Josée, a superb girl, is the mistress of Gueule en or, one of the smugglers.

Life could be so sweet for Gus Vermeulen and Achille Mironval. They are partners in a cheese trade and business is good. So what they plan to do is to marry their two children so as to perpetuate this blissful situation. However two annoying facts cast a shadow over their happiness. Jean-Pierre Mironval, Achille's son, won't hear of anything connected with cheese and would rather be a jazz band leader and Gus, with his passion for spiritism, sows the seeds of discord between the two men. But all is well that ends well.