Lyria, a faded beauty who runs a seedy waterfront bar, is madly in love with Bob, a crooked attorney. Bob can't bring himself to confess his love for Minnie, the pretty daughter of Simon, a safe cracker. In order to run away with her, Bob, one of the masterminds of a big-time robbery, betrays his friends. But Lyria, who has found out what is happening, makes Minnie fall into a deadly trap.

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.