A hot shot flyer discovers the hero within when he joins the British Air Force during World War II.

Prior to the United States' entry into World War II, egotistical American pilot Tim Baker seeks adventure and money by ferrying a bomber from Canada to England. While in London, he meets a former girl friend, Carol Brown, a nightclub performer who volunteers in the ambulance reserve during the day. Carol is both pleased and annoyed to see Tim, with whom she broke up a year earlier because of his irresponsible nature. Hoping to win Carol back, Tim accepts her dare to join the R.A.F. but quickly becomes bored with the classes teaching basic flying techniques. One afternoon, Carol goes to the airfield and meets Wing Commander John Morley, who is immediately taken with her. Morley sees her nightclub show and escorts her home, after which Carol, angry at Tim for standing her up that evening, tells him that she has a new man in her life. She continues seeing both of them while Tim finishes his training and is assigned to Morley's squadron, but the men are not aware that they are romantic rivals. One night Tim makes a trial run with Corporal Harry Baker, during which they are to drop propaganda leaflets on Berlin. Tim is disgusted with what he perceives to be a useless task, but returns to the base safely and tells Carol that he will be late for their date that night. When Tim arrives at four in the morning, however, after carousing with friends Al Bennett and Roger Pillby, Carol has left her apartment for a weekend in Kent with Morley. Tim's perpetual nonchalance about her, combined with the enjoyable weekend, prompt Carol to tell him that they are through when she returns to London. Upon learning that the other man proposed, Tim offers to marry Carol as well, but the self-sacrificing tone he adopts makes Carol throw him out. When Tim returns to the base, he and Morley discover that they are both Carol's suitors, but just then, they are called on an emergency mission to Dortmund because Germany has invaded Holland and Belgium. Pillby is shot down as he draws fire from Tim after his plane is hit, but Tim is still forced to land on a Dutch beach because of a lost engine. A German patrol spots Tim, Morley and Baker, and Baker bravely sacrifices himself so that the others can escape. Tim attempts to play on Carol's sympathy when he returns by pretending to have a broken arm, and despite her aggravation at the ruse, he forces an engagement ring on her before he has to return to the airfield on another emergency call. At the base, Tim learns of the siege at Dunkirk and finally has a chance to fly a Spitfire as the squadron takes off. After shooting down two German planes, one for Pillby and one for Baker, Tim is shot down himself and appears to be lost. Morley returns safely and realizes that Carol is in love with Tim as she tries to convince herself that he will be okay. They rush to one of the last returning boatloads of evacuated soldiers and are about to give up hope when Tim appears. Carol tearfully shows him that she is still wearing his ring, and after Morley congratulates Tim, the trio walk off arm in arm.