The young and patriotic student Demachy joins the French army in 1914 to defend his country. But he and his comrades soon experience the terrifying, endless trench war in Champagne, where more and more wooden crosses have to be erected for this cannon fodder.
The story is about a drug ring and the finally successful efforts of the Paris police to break it up. A young detective goes into a den in Paris' Chinatown, following a clue, and that is the last seen of him until his body is found floating in the Seine several days later. The only clue is a woman's glove. The dead man's friends on the force vow to avenge him, and receive information leading them to suspect one Sandra, a beautiful foreigner, played by the stunning Marcelle Chantal.
During the First World War, before joining a squadron at the front in 1918, Herbillon (Jean-Pierre Aumont) has a liaison with Helene (Annabella), a married woman. The young man discovers that his mistress is none other than the wife of Maury (Charles Vanel), an aviator friend.
