Three years after the 1959 expedition, abandoned 350m from the summit, Lionel Terray leads a new assault on Jannu, one of the most demanding peaks in the Himalayas. At the base camp, equipment and food rations are prepared. The conditions are optimal and the ascent can begin. The camera follows the progress of the mountaineers and Sherpas as closely as possible, from one high-altitude camp to another: installing fixed ropes, progressing over crevasses, in the middle of frozen towers, vertically down immense ice falls or along the edge of sharp ridges. From 7000m, oxygen bottles become essential, as the difficulty of the climb prevents acclimatization. The expedition is a total success: the majority of its members reach the 7710m summit.