Set against the backdrop of the shell crisis of 1915 at home and the Battle of Loos on the Western Front, two soldiers, one the manager of Grimlaw’s munitions factory are tested in their rivalry for Diana, a red cross nurse (Madeleine Carroll in her first film role).
Pierre Boucheron, alias 'The Rat' and a former underworld notoriety, is now living the high life as the kept man of Zelie de Chaumet. But when she learns he is planning to marry another woman, her vengeance pursues him into the murkiest depths of Paris...
A colonel's son conquers his cowardice by fighting his rival for a gypsy.