Twins Kitty and Harris Hawk have grown up at the airfield where their father works as an engineer. Kitty in particular is obsessed with the idea of becoming an aeronaut but her father thinks children should stay firmly on the ground. When the twins discover a strange and unusually large egg from which a dragon hatches, little do they imagine that this is the first step on a journey that will see them taking to the skies and competing in the first long-distance air race.

Can they win the huge prize that's at stake and will their daring adventure lead their father to change his mind about Kitty's future?