Joseph Stalin - the supreme leader of the Soviet Union - was a tyrant responsible for the death of millions. Yet he also had some unlikely relationships during the Second World War. Not just with leaders of the great democracies like Winston Churchill and Franklin Roosevelt, but also with Hitler and the Nazis. For the first time on television, this ambitious series, from award-winning filmmaker Laurence Rees, lifts the lid on these relationships to reveal the true natures of the three leaders and how the meetings they had - and the decisions they made - shaped the world today.