Both teams are trapped in camp at high altitude by unexpectedly high winds that threaten to wreck their summit bid. It's particularly bad news for Mogens Jensen who is climbing without supplementary oxygen and can ill afford extra time in such thin air. When the weather relents next day, Mogens sets off into the Death Zone. He got within 400m of the summit last year before having to turn back with frostbite, but summiting without oxygen would be an extraordinary achievement and the Death Zone is unforgiving. At 1am, Team One leave top camp for the summit but almost immediately get caught in a human traffic jam that stops them in their tracks. If they can't pass some of the slow climbers ahead of them, they will run out of time and oxygen.