During the torrid Summer of 1919, in a small French town, a war hero is imprisoned in a disused barracks, accused of a grave act of provocation towards the French nation and its army. The magistrate in charge is an aristocrat and veteran of the battle of the Somme, whose values have been deeply shaken by war.

As a heatwave crushes the town, the magistrate strives to understand the war hero’s motivation. Will he be able to piece together the story of the war hero and his inseparable companion, a loyal dog?