Documentary exploring the events of 15 September 1940, the day Churchill described as the 'crux of the battle' and which is now celebrated as Battle of Britain Day. Dramatic colour film footage of aerial combat, combined with contemporary interviews, illustrate how the events of that summer still resonate with a new generation. The programme offers a gripping and powerful account of a nation united behind the pilots of Fighter Command who defended Britain from the might of the Luftwaffe.