THE MYSTERY OF U-33: Hitler's Secret Envoy

Chronicles a number of mysterious U-Boat missions that took place both during and after the war. Graddon details the strange landing of U-33 in Scotland in 1940, which involved the top-secret Enigma encoding device, then looks at other special U-Boat missions: U-Boat trips to Antarctica, curious cargoes of liquid mercury, the "Black Subs," and more. Photos.