Bismarck displaced 41,700 tons standard and over 50,000 fully loaded, stretched 251 meters, carried eight 38-centimeter guns in turrets named Anton, Bruno, Caesar, and Dora, and secretly violated the 35,000-ton limit of the 1922 Washington Naval Treaty. Its active combat career lasted eight days. This episode follows the ship from Operation Rheinubung in May 1941 with Prinz Eugen to the bottom of the Atlantic, and on to Robert Ballard’s 1989 discovery of the wreck nearly three miles down.

The story turns on a flaw found in Baltic sea trials in late 1940: with its broad beam and three closely clustered propellers, Bismarck could not be steered by engines alone if the rudders failed. Institutional arrogance and wartime urgency sent it to sea anyway, where Swedish aircraft, the cruiser Gotland, Norwegian resistance radios, an RAF Spitfire photo run, and Bletchley Park codebreakers reading requests for navigational charts tracked every move while Admiral Lutjens believed the British were unaware.

• Denmark Strait, May 24: Lutjens hesitates under fire, Captain Lindemann forces the order to engage, and a plunging shell tears HMS Hood in half in eight minutes with only three of 1,419 survivors
• The Prince of Wales hit below the waterline that flooded a generator room, cut off bow fuel, and forced a run for Luftwaffe cover in France
• Lutjens’s fatal 30-minute radio message, sent because he wrongly assumed British radar was still tracking him after he had shaken his pursuers
• Why Bismarck’s advanced anti-aircraft computers could not track 90-mph Fairey Swordfish biplanes, why gunners fired main guns into the sea to make splashes, and the torpedo that jammed the port rudder at 12 degrees
• Scuttling versus gunfire: what the intact, un-imploded hull reveals about Hans Oels’s final order, why 114 of over 2,200 men survived, and why the Royal Navy still won