Shinano was laid down in 1940 as the third Yamato-class battleship, converted after Midway into the heaviest aircraft carrier ever built, and sunk ten days after commissioning without ever launching a combat strike. This episode explains the death-penalty secrecy surrounding its construction, the open-sided hangar and 2,400 metric tons of concrete poured around its fuel tanks, and the manually aimed anti-aircraft guns that looked formidable on paper but shook too violently to aim.

It then follows the rushed floating-out accident, the B-29 photograph that panicked the Navy into ordering the ship to sea with missing watertight doors, unsealed bulkheads, and no pumps, and Captain Toshio Abe's denied plea for a delay. The conversation covers the USS Archerfish's pursuit, Commander Joseph Enright's shallow-running torpedoes, the weak seam betwee ...