Krakauer, worried about the oxygen supply, does not stay at the top long enough to string up banners or flags or pose for pictures. He turns to descend, passing some members of Fischer's expedition along the way. Krakauer notices some thin clouds, but does not recognize them as thunderheads. At Hillary Step he encounters a traffic jam and must wait for the other climbers to ascend. Krakauer asks Andy Harris to turn down his oxygen so as to preserve it until he can get another one, but Harris mistakenly opens the valve even farther and after ten minutes, Krakauer is out of oxygen.
Krakauer passes Hall who is disappointed that five of the team members turned back before reaching the summit. The traffic jam continues for upwards of an hour, and Krakauer waits without supplemental oxygen, feeling dangerously close to incapacitated. Terribly frightened to be maneuvering without extra gas, Krakauer slowly descends to the South Summit, where extra canisters of oxygen await. He asks Andy Harris to get him one, but Harris responds that all of the canisters are empty. Harris gives Krakauer his bottle, and Krakauer stops to examine the canisters. He finds that most of them are in fact full. In hindsight he realizes that Andy is suffering from hypoxia, or altitude-related impaired judgment and berates himself for not having realized that at the time. Krakauer explains that as a guide, he tended to see Andy as less susceptible to illnesses like hypoxia, and might have been suffering the effects of it himself. Krakauer leaves Andy there, and continues to descend—something he says he will regret forever.
At this point, all of the climbers except one have begun the descent, and most are accompanied by guides. Krakauer keeps going until he descends to 27,600 feet where he sees teammate Beck Weathers, who had decided to turn back hours before. Weathers is suffering the effects of an eye surgery he underwent some years before. The lower pressure on the mountain was causing his eyesight to fail. Weathers hadn't mentioned this condition to any of the guides, but now could not see anything. In addition to complications surrounding his surgery, he accidentally rubbed ice crystals into his eyes, cutting up his corneas. Weathers had eventually turned back after revealing the situation to Hall, but then convinced Hall to let him have another go, that perhaps his eyesight would improve once he neared the top. Hall gave Weathers thirty minutes—if his eyesight was better he could continue, but if it wasn't he had to promise to sit and wait for a guide.
The weather is beginning to look ominous, and Krakauer offers to accompany Weathers down the mountain. Weathers declines, though, because Krakauer mentions that more climbers were just behind him. Weathers decides to wait for that group.
Krakauer has trouble on the descent because the snow and wind have obscured the tracks made when they ascended the mountain, and he is not sure he is following the correct route. He tries his best to remember landmarks and guide himself down the correct path when he hears thunder. By the time he descends that stretch of mountain it is 6:00 pm, and he is caught in the middle of a blizzard.
Again, he realizes that he is running out of oxygen. Krakauer begins to hallucinate, his mind retreating to the place it goes when it starves for oxygen. Just 600 feet from the tents, Krakauer pauses to conserve his energy. While resting, Andy Harris catches up to him. Harris's cheeks are covered in frost and an eye is frozen shut. Krakauer points in the direction of the tents and Harris slips over a lip of ice, scooting down the mountain on his rear end. At one point Harris tumbles over, but is okay and runs off toward the tents.