In the European Theatre of World War II in no other factor was Britain closer to defeat than in the Battle of the Atlantic. With U-Boats Vice Admiral Karl Dönitz planned to starve the United Kingdom into submission by sinking vital shipping. This series recounts the struggle of the Allies to find a means to combat this menace with new technology and tactics and breakthroughs in decrypting enemy messages. Taken together the longest battle of the war is surveyed with the fate of the free world in the balance.