A 600-foot heavy cruiser sets a trans-Pacific speed record, delivers the core components of the atomic bomb, and then vanishes from the US Navy’s radar for four days with more than 1,000 men aboard, and nobody notices. This episode builds a biography of the USS Indianapolis and her final commander, Captain Charles B. McVay III, using declassified naval documents and ship schematics to understand how systemic failures happen.

We begin with her birth as a treaty cruiser whose armor was sacrificed for speed and eight-inch guns, her peacetime years as FDR’s diplomatic flagship, and her Pacific combat record from the Philippine Sea to the Okinawa bomb hit that sent her home for repairs. Then we follow the secret mission carrying 85 pounds of enriched uranium bolted to the deck of the captain’s quarters, the two Type 95 torpedoes from submarine I-58 that sank her in 12 minutes, four days of dehydration, hallucination, and shark attacks, and the chain of failures that ensured no one was looking. Finally, we examine McVay’s court-martial, his suicide in 1968, and the 11-year-old whose history project led to his exoneration in 2000.

• How top-heavy anti-aircraft upgrades turned a thin hull into a ship that rolled over and sank
• The Manhattan Project doctor who faked seasickness to monitor radiation in the captain’s cabin
• Negative reporting, three ignored SOS signals, and an officer who ordered not to be woken
• Adrian Marks landing a PBY Catalina in 12-foot swells and lashing survivors to its wings
• Commander Hashimoto’s testimony that zigzagging would not have mattered, and Hunter Scott’s campaign