It is 1940 and Britain is at war with Germany. In London, eighteen-year-old Susan Banks longs to do her duty. Her secret ambition is to learn to fly - to serve her country and realise her dream. But she knows it is out of the question for a girl like her; a foundling, unwanted and unloved and dependent on strangers for her welfare. Just as she fears she will be trapped forever in a life of servitude and loneliness, she meets Tony Richards, a flying instructor based in Hampshire. And when she is forced to flee London, she heads out into the country. She is taken in by the kindly landlord of the local inn and his daughter. As Susan works hard to earn her keep, and her friendship with Tony - now recalled to duty - blossoms into love, she dares to hope that things are at last looking up for her. But then she receives devastating news - Tony is missing in action. And Susan wonders if she'll ever see the man she loves again and realise her dream of becoming a Spitfire girl...