Dick Wright, rejected by both the Army and the Navy because he is a sleepwalker, joins an ambulance unit during the war, and his chauffeur and valet go along to protect him. By accident they get aboard a regular troop train and arrive in France as members of the U. S. Army. After a series of comic adventures with a hard-boiled sergeant, Ted and Sam succeed in capturing a detachment of Germans and are decorated for their bravery. Along the way, the boys are involved in romantic interludes with Betty and Joan, respectively American and French.