A true adventure in which two amateur scuba divers risk everything to solve a great historical mystery - and make history themselves'This book is a work of art' RYAN HOLIDAY'A pulse-quickening real-life thriller'New York Times 'A memorable story, beautifully told'The TimesFor John Chatterton and Richie Kohler, deep wreck diving was more than a sport. But in 1991, not even these courageous divers were prepared for what they found 230 feet below the surface, in the frigid waters of the Atlantic: a Second World War German U-boat, its ruined interior a macabre wasteland of twisted metal, tangled wires and human bones.No identifying marks were visible. No historian, expert or government had a clue as to which U-boat the men had found, and the official records all agreed that there simply could not be a sunken U-boat and crew there.Over the next six years, an elite team of divers embarked on a quest of increasingly perilous diving and painstaking archival research to solve the mystery. Some of them would not live to see its end. Chatterton and Kohler, at first bitter rivals, would be drawn into a friendship that deepened to an almost mystical sense of brotherhood with each other and with the drowned U-boat sailors – former enemies of their country.Bestselling author Robert Kurson’s account of this quest is thrilling, vivid and emotionally complex. It’s a story of persistence, ingenuity and a shared obsession.