In 1943 a squadron of Lancaster bombers staged one of the most audacious raids in military history: destroying two gigantic dams in Germany’s industrial heartland and cutting the water supply to arms factories. Their secret weapon? A revolutionary bouncing bomb invented by British engineer Barnes Wallis. Wallis and the pilots of 617 Squadron—a lively mix of Britons, Australians, Americans, and Canadians—were hailed as heroes who dealt a mighty blow to the German war machine. Now, NOVA recreates the extreme engineering challenges faced by Wallis and the pilots. A crack team of experts, including dam engineers, explosives specialists, mechanics, and aircrew, steps into the shoes of the "dambusters" and attempts to overcome each of the obstacles the original team faced. They must adapt a vintage World War II DC-4 to carry a bomb the size of an oil drum, train to drop it from a dangerously low altitude in pitch darkness, and get it to bounce over obstacles and onto the target, a scale model the German dam struck by the original dambusters. Can they succeed in destroying the dam and unraveling the mysteries of the one-of-a-kind bouncing bomb?