By Sarah Rainsford
BBC Moscow correspondent
By Steve Rosenberg
BBC News, Moscow
The story of the first meeting of the 'Big Three', Churchill, Roosevelt and Stalin, at Tehran. Plus, the secret history of the Soviet attempt to cover up the mass murders at Katyn.
An exploration of the secret history of Churchill's first meeting with Joseph Stalin in Moscow and the behind-the-scenes actions of Roosevelt's emissary to the Soviet Union.
The secret history of Stalin's dealings with Churchill and the West in the wake of the German invasion of the Soviet Union.