March 1944: in German-occupied France, another conflict rages between the children of the two neighboring villages Langeverne and Velrans. The youngsters defend their honor or that of poached territory in battles strategically prepared after class, collecting the buttons of their adversaries to humiliate them. A new girl comes to one village: the daughter of the pretty shopkeeper (Laetitia Casta) newly returned from the capital. Lebrac, the boss of the local band of children, falls for her, as his teacher (Guillaume Canet) seems charmed by her mother. But there is a traitor in their midst and the fear of informants spreads through the village. Time to choose sides and for all to show their true colors.

A foreseeable story about the comparison of resistors and collaborators during the war. With postcard imagery of the 1940's, a profusion of feel-good emotions and a tendency to oversimplify the traitor as small and fat or as a nasty redhead too small for his uniform – while the good guys always smile the smile of the just. The movie's tone is very dualistic and self-righteous, as if over-enunciating for children. For those who survived Les Choristes, also by Christophe Barratier, there is even a small musical reminder of that film.