In wartime London just before D-Day, Lieutenant Commander Charlie Madison, an aide to eccentric Rear Admiral Jessup, specializes in supplying the top Navy officers with luxuries such as party girls.  Madison is an exponent of cowardice as a virtue because he believes reverence of heroism promotes war.  He falls in love with Emily Barham, his British motorpool driver, a young woman who has lost her husband and brother in the war.

Admiral Jessup is obsessed with the idea that the Army has a better image than the Navy and is determined that the first dead man on Omaha Beach on D-Day be a sailor.  Jessup orders Madison to photograph the D-Day landing and, despite his protests which alienate Emily, Madison is forced at gunpoint to be the first man to land on Omaha Beach.  Running from the bombs, Madison trips a land mine and is reported to be the first man killed in the invasion.

Photographs of his supposedly dead body appear in the newspapers, and he becomes a hero, but later he is found alive.  Admiral Jessup then organizes a hero's welcome for Madison, but he threatens to confess the true story of his cowardice to the press.  Emily, in a reversal of sentiment, promises to marry him if he will keep his secret, and Madison agrees to remain quiet.