On 1 August 2008, 18 climbers from across the world reached the summit of K2, the world's second highest and most dangerous mountain - a peak which claims the life of one in every four climbers who attempt it. Over the course of 28 hours, however, K2 had exacted a deadly toll: 11 lives were lost in a series of catastrophic accidents. Attracting a climbing elite and standing at 8,611 metres on the Pakistan-China border, K2 is known as the 'Mountaineer's Mountain' because of its extreme technical challenges, its dangerously unpredictable weather and an infamous and hazardous overhanging wall of ice known as the Serac. Snow-bound at Base Camp for weeks on end and increasingly despairing of their prospects of success, an unexpected weather window gave the climbers the opportunity they were waiting for. In their collective desire to reach the summit, seven expeditions agreed to co-ordinate their efforts and share their equipment. Triumph quickly turned to tragedy, however, when a seemingly flawless plan unravelled with lethal consequences. Over the course of three days, a Nepalese Sherpa called Pemba Gyalje, along with five other Sherpas, was at the centre of a series of attempts to rescue climbers who had become trapped in the Death Zone, unable to escape its clutches and debilitated by oxygen deprivation, chronic fatigue, delirium and a terrifying hopelessness. The tragedy became a controversy as the survivors walked from the catastrophe on the mountain into an international media storm, in which countless different stories emerged, some contradictory and many simply untrue. Based on Pemba Gyalje's eyewitness account and drawing on a series of interviews with the survivors which were conducted for the award-winning documentary, The Summit (Image Now Films and Pat Falvey Productions, 2012), The Summit: How Triumph Turned to Tragedy on K2's Deadliest Days is the most comprehensive interpretation of one of modern-day mountaineering's most controversial disasters.