The story of the destruction of the major dams in Germany's industrial heartland in the Ruhr valley in 1943, a mission that seemed impossible until engineer and scientist Barnes Wallis came up with the ingenious idea of bouncing bombs, and the pilots of 617 Squadron were trained to fly the crucial mission. Second World War drama, with Michael Redgrave, Richard Todd, Basil Sydney, Derek Farr and Ursula Jeans