John Andrews, called Andy, a Harvard-trained musician who finds himself in the enlisted ranks during World War I. He is intelligent and sensitive, and he hates the Army for trying to make a machine of him. Returning to his regiment from the hospital after he has suffered a wound in his leg from a bursting shell, he is full of rebellion. He is convinced that humanity should not tolerate war. He goes absent without leave but is caught and sentenced to hard labor. He escapes and hides out at an inn near Paris. There, working on a musical composition, he is again arrested by the military police.
Chrisfield, a violent soldier from Indiana. Chrisfield hates and loves quickly and passionately. He kills a German officer in cold blood and slays a hated American lieutenant named Anderson as the officer, wounded, waits for help in a clearing in a forest. When Chrisfield comes to suspect that the authorities know that he killed Anderson, he goes absent without leave and spends his days as a refugee in France.
Dan Fuselli, a whining, sniveling, and groveling American private from San Francisco whose only ambition is to become a corporal. He spends much of his time in France paying court to noncommissioned officers who might get him promoted. His French girlfriend, Yvonne, is stolen from him by a sergeant. He becomes a corporal after the Armistice but learns, at about the same time, that his girl back home has married a naval officer.
Geneviève Rod, a young Frenchwoman who admires Andrews’ musicianship and his good taste but cannot understand the motive behind his rebellion.