Historical documentary which explores the efforts of German soldiers during World War II. The outbreak of the Second World War meant that both sides had to concentrate a huge amount of their workforce on rearmament, with large amounts of supplies being delivered by air. The German army relied heavily on their U-boats, and with ambush tactics devised by their creator, Admiral Doentitz, they became a dangerous force on the water. The programme includes rare footage of former captains and U-boats in action.