Plot: In the final part of his personal account of Britain's empire, Jeremy Paxman tells the extraordinary story of how a desire for conquest became a mission to improve the rest of mankind, especially in Africa, and how that mission shaded into an unquestioning belief that Britain could - and should - rule the world. In Central Africa, he travels in the footsteps of David Livingstone who, though a failure as a missionary, became a legendary figure - the patron saint of empire who started a flood of missionaries to the so-called 'Dark Continent'