Episode 2

World War II's longest campaign was fought in the Atlantic Ocean. Hitler's U-boats hunted in packs, chasing down the convoys which were bringing vital supplies to Britain. Churchill wrote that his greatest fear in the entirety of the war was the U-boat peril, and by the beginning of 1943, the Germans had the upper hand at sea. However, through a combination of new tactics, weaponry and heroic convoy commanders, the Allied forces began to fight back.

Throughout, the port of Derry played a pivotal role as the UK's most westerly base. Historians explore the story of a group of Irish merchant seamen who found themselves captured and enslaved in the horror of a Nazi labour camp.