This final episode tells the story of how Britain's industrial heartlands have been transformed in the space of a single lifetime. In 1939 the Luftwaffe secretly photographed the backbone of the British economy: the valleys of South Wales where the great coalfields powered the nation; Swindon, at the heart of Britain's railway network; and Manchester, home to the great port of Salford and the world's largest industrial estate Trafford Park. Comparing those images from almost seventy years ago with those from today, the sheer scale and speed of change becomes vividly apparent. Where there were factories there are now fields, mining villages no longer have mines, docks have been replaced by high spec waterside apartments. Seen from above it is clear that no other aspect of the nation has changed so much or so quickly. It is a story of evolution, adaptation and, in some places, extinction.