On July 30, 1945, the USS Indianapolis was torpedoed in the South Pacific by a Japanese submarine. An estimated 300 men were killed upon impact; close to 900 sailors were cast into the Pacific Ocean, where they struggled to stay alive for four long days, fighting off sharks and hypothermia. Interweaving the stories of three survivors—the captain, the ship's doctor, and a young marine—Doug Stanton answers the many lingering questions about this incident, which led to the captain's court martial.