David W. Jourdan recovers the sunken history of the Japanese cargo-carrying submarine I-52, exploring air-sea-undersea warfare and Japanese technology during World War II. World War II gave rise to tales of epic battles, sagas of heroism, bravery, and cowardice. The sinking of Japanese submarine I-52 is one such tale. Author David W. Jourdan recovers this sunken history and explores how Allied codebreaking, the victory over the Axis's desperate mission for much-needed resources, and a modern-day treasure hunt contributed to the contemporary understanding of resource manipulation, air-sea-undersea warfare, and Japanese technology during World War II. In the final year of the war, Germany and Japan were increasingly starved of resources that they needed to continue the conflict. Because of this, the sinking of the Japanese cargo-carrying submarine I-52 played a crucial role in the tipping of Allied-Axis power. The submarine was conducting the last mission of a desperate program called Yanagi, aiming to transport vital war supplies, technology, and human expertise between the Axis confederates, before it was caught and destroyed in a combined air, sea, and undersea battle. Its mission, cargo, and movements were known to the Allies by codebreaking efforts, and its sinking denied Germany sorely needed rubber, metals, chemicals, medicines, industrial designs, weapons technology, and know-how. Incidental to the hundreds of tons of military supplies was a shipment of gold. The subsequent interest of modern-day treasure hunters has given ocean explorers, like Jourdan, the chance to uncover the details of such a unique historical event. The research that was stimulated by this effort led to the discovery of one-of-a-kind recordings of American Avenger torpedo bomber attacks on an enemy submarine. One of the first joint American-Russian research expeditions, the search for the wreck of I-52 and its discovery on the seafloor, nearly intact over three miles deep, accompany the historical account of the submarine with a tale of teamwork, detective work, and mariners' battle with the sea.