It's 1943 and German U-boats continue to decimate allied shipping. The allies must find a way to defeat Admiral Karl Donitz's "wolfpack" or they will lose the war. The stakes have never been higher, the battles have never been larger and the casualties have never been higher. By the time World War II ends, no other branch of the armed forces will suffer as a high a mortality rate. Hear the stories from the German and allied soldiers, who still carry with them the haunting memories of the Battle of the Atlantic.