Book excerpt: London, 15 September 1940. The air battle over Britain on that day saw two of the most advanced fighter planes, the British Supermarine Spitfire and the German Messerschmitt Bf 109, battle for supremacy of the skies. The Decisive Duel tells the stories of these iconic, classic aircraft and the people that created them: Willy Messerschmitt, the German designer with a love for gliders and admiration for Hitler; R.J. Mitchell, his brilliant British counterpart, who struggled against illness to complete the design of the Spitfire. In fascinating detail, David Isby describes the crucial role the two opposed planes played, from the drawing boards to Dunkirk, the Battle of Britain to the final battles over Germany.