The dark glow of the mountain (1985)

Werner Herzog follows mountaineers Hans Kammerlander and Reinhold Messner during their expedition into climbing the Gasherbrum mountains, which has some of the most difficult peaks to be conquered, and they'll do it without the use of oxygen tanks. Herzog also takes some time to hear about their past experiences with other mountains, their personal tragedies and the reasons why they are so involved with such activity.