The third series follows the tense struggles of a young U-boat crew as they engage in the Battle of the Atlantic whilst being hunted down by an obsessed Royal Navy Commander in a thrilling game of cat-and-mouse. They are sent on a dangerous mission to the Southern Hemisphere under the command of Robert Ehrenberg (Franz Dinda) who finds redemption and the family bonds he thought he’d lost forever. The drama takes us to Northern Germany’s Kiel, the major naval base of the German Reich for the first time, with each historically based strand leading to an epic series finale.