In 1991, 60 miles off the coast of New Jersey, at the incredible depth of 230 feet underwater, two amateur divers, John Chatterton and Richie Kohler, find what divers dream about: an undisturbed wreck that they soon identify as a German U-boat. But there is no official record of this warship, and no historian or government can solve the puzzle. So this unlikely duo and their team of daredevil divers embark on a perilous quest: to identify the shadowy vessel who they’ve nicknamed ‘U-Who’. But plunging into the murky depths raises its own questions, and not everybody will make it back to the surface. After years of increasingly risky diving, painstaking archival research, and gaining the trust of retired U-boat crew, the team finally identify it as U-869 and work out what on earth it’s doing there. But Chatterton and Kohler, whose rivalry has turned to friendship won’t stop there – they decide to trace the families of the men who died on