Tim Baker (Tyrone Power) is a cocky but easygoing American pilot who signs up to ferry a bomber to Britain in the early days of World War II. When he encounters old flame Carol Brown (Betty Grable) performing in a London cabaret, Tim decides to stay in England and join the Royal Air Force. He soon finds that one of his fellow flyers, Wing Commander Morley (John Sutton), is a romantic rival for the attentions of Carol. But as the Nazi threat becomes more pressing, Tim and Morley put aside their differences and pull together to participate in the daring evacuation of the Allied troops from Dunkirk.