January 1, 1993, Europe opens its borders. Two customs officers, one Belgian, the other French, learn of the imminent disappearance of their border crossing situated in Courquain (France) and Koorkin (Belgian). French-speakers from father to son and far too zealous at his job, Belgian Ruben Vandevoorde is forced to inaugurate the first French-Belgian mobile brigade. His French colleague, Mathias Ducatel, considered by Ruben as his sworn enemy, is secretly in love with Ruben's sister. He surprises everyone by accepting to become Vandevoorde's team-mate and to patrol the country boarder roads with him in a powerfully small, cramped, international customs vehicle.