Six soldiers and their lieutenant are on an exploratory mission a few days before the end of a training course. Unfortunately, due to a mistake, the group gets lost and accidentally ends up on French territory. The lieutenant is then faced with a real dilemma: returning to Switzerland via the nearest customs post means accepting the legal consequences—in fact, any Swiss national who crosses the border with an assault rifle is automatically considered a deserter—or returning to the country illegally through the forest, which is foreign territory and sometimes dangerous.

As a newly arrived pianist starts rehearsing, her neighbor starts a sound war that very rapidly brings all the neighbors to their windows. While everyone shouts at each other, the pianist plays till she faints. When the police witness the crowd of hysterical neighbors shouting at each other, they take the side of the pianist, who, after a moment of intense madness, is now playing a serene Mozart piece.