At base camp, Russell realizes that some climbers aren't quite ready for the rigors of Everest. Meanwhile, the team realizes what they are up against when they witness two professional climbers fighting for their lives in the Death Zone.
Russell sets a five-hour deadline for his team to climb 2,000 feet to the first high camp at the top of a punishing ice cliff. Two days later, the expedition must climb even higher to continue their acclimatization. Betsy continues to struggle and is given one last chance.
The team is at 24,500 feet - higher than anywhere outside the Himalayas - but the sun is beating down and it's incredibly hot. Even the fittest climbers are struggling with dehydration and exhaustion as they try to reach Camp 2.
Training and the acclimatization climbs are over, and the expedition leaves base camp heading for the summit. David Tait and Phurba Tashi are within hours of the summit, but even if they make it, they're only a quarter of the way through their attempt to complete a double-traverse of Everest's north and south faces.
As Team One sets off for the summit, Tim is last out of camp and taking his time on the first leg to Camp One. On his way down the south side from the top of Everest, David drops a bombshell that leaves Russell stunned.
Team One fights its way to Camp 4 at 27,500 feet, inside the Death Zone where their bodies are slowly dying from lack of oxygen. After suffering an asthma attack, Mogens may have to give up his dream of summiting without oxygen.
Five miles high in the Death Zone, Team One set off for the summit at midnight in extreme cold. But before the sun rises, Tim finds himself in big trouble when he falls and snaps two bones in his left hand.
Mogens leaves Camp 4 on his fourth attempt to climb Everest, this time with bottled oxygen. Also on his way to the top is 71-year-old Japanese climber, Katsusuke Yanagisawa, who will be the oldest person ever to summit if he makes it.