Summer 1940: The Battle of France is over; the Battle of Britain is about to begin. If the swastika is not to fly over Buckingham Palace, the RAF must prevent the Luftwaffe from gaining air superiority over Great Britain. Standing on the front line is No. 606 (Hurricane) Squadron. As the casualties mount, new pilots find a cold reception from the clique of experienced pilots, who resent them taking the place of their dead friends. Meanwhile, despite credible service in France, former RAF aerobatics pilot Robin Priestman finds himself stuck in Training Command -- and falling for a girl from the Salvation Army. On the other side of the Channel, the Luftwaffe is recruiting women as communications specialists -- and naïve Klaudia is about to grow up.