At the outset of World War II, US and UK military aircraft designs were woefully behind Nazi Germany's technologically superior planes - German designers had already flown the first jet. But the genius and ingenuity of innovators on both sides of the Atlantic closed the gap. They produced planes such as the chance Vought Flying Pancake, a saucer-shaped naval fighter that could take off vertically. Or the Northrop MX-334 Flying Wing, a rocket-powered fighter with armoured wings designed to ram German bombers. And perhaps the biggest secret project outside the Manhattan project to build the atomic bomb - Churchill's plan to build a fleet of giant aircraft carriers made of ice, designed to act as floating airfields for the invasion of Japan. Using specially commissioned computer graphics, never seen archive footage and interviews with aviation experts, we bring back to life the secret allied planes of the Second World War.