In February 1959, a group of nine experienced hikers in the Russian Ural Mountains died mysteriously on an elevation known as Dead Mountain. Eerie aspects of the incident—unexplained violent injuries, signs that they cut open and fled the tent without proper clothing or shoes, a strange final photograph taken by one of the hikers, and elevated levels of radiation found on some of their clothes—have led to decades of speculation over what really happened. This New York Times bestseller is a gripping work of literary nonfiction delves into the mystery through unprecedented access to the hikers' own journals and photographs, rarely seen government records, dozens of interviews, and the author's retracing of the hikers' fateful journey in the Russian winter. A fascinating portrait of the young hikers in the Soviet era, and a skillful interweaving of the hikers narrative, the investigators' efforts, and the author's investigations, here for the first time is the real story of what happened that night on Dead Mountain.