In 1943 a squadron of Lancaster bombers staged one of the most audacious raids in history — destroying two gigantic dams in Germany’s industrial heartland and cutting the water supply to arms factories — with a revolutionary bouncing bomb invented by British engineer Barnes Wallis. Wallis and the pilots of 617 Squadron dealt a mighty blow to the German war machine. Now, NOVA re-creates the extreme engineering challenges faced by Wallis and the pilots with the aid of six spectacular experiments. Each represents a technical challenge that the “Dambusters” had to solve to make their mission a success. A team of experts — from dam engineers to explosives specialists — steps into the shoes of the Dambusters. They will adapt a vintage World War II DC4 to carry a bomb the size of an oil drum; train to drop it from a dangerously low altitude in pitch darkness; get it to bounce over obstacles and onto the target; and finally, at a test site in Canada with a 1:6 scale model of one of the German dams, try to repeat history.