Over 4000 people have reached the summit of Everest. Fewer than 300 have done so on K2. One in twenty people who reach the summit of Everest die. On K2 it's one in three.
Then, in 24 hours in August 2008, eleven climbers died in what remains the single deadliest disaster in climbing history. Drawing on interviews with the survivors - and their rescuers - this is a minute-by-minute account of that tragedy. And one which, for the first time, illuminates the extraordinary role played by the Sherpa guides.