On August 1, 2008, no fewer than eight international teams of mountain climbers some experienced, others less prepared ascended K2, the world's second-highest mountain, with the last group reaching the summit at 8 p.m. Then disaster struck. A huge ice chunk came loose above a deadly three-hundred-foot avalanche-prone gully, destroying the fixed guide ropes. More than a dozen climbers many without oxygen and some with no headlamps faced the nearly impossible task of descending in the blackness with no guideline and no protection. Over the course of the chaotic night, some would miraculously make it back. Others would not.