Rich boy Dick Wright, rejected by both the Army and the Navy because he is a sleepwalker, joins an ambulance unit during the war with his chauffeur and valet tagging along to protect him. They accidentally get aboard a regular troop train, arriving in France as members of the U. S. Army. Following a series of comic adventures with a hard-boiled sergeant, Ted and Sam succeed in capturing a detachment of Germans, receiving decorations for their bravery. Along the way, the boys engage in romantic interludes with Betty and Joan, respectively American and French.