Longtime rivals in the Marines, Capt. Flagg (James Cagney) and Sgt. Quirt (Dan Dailey) are stationed together in France during World War I. Soon the two tough military officers are competing for the hand of pretty local girl Charmaine (Corinne Calvet). Flagg and Quirt get into plenty of trouble, but their playful brawling eventually gives way to camaraderie, particularly when the realities of war set in as the soldiers head back out to the battlefield.