Lower on the mountain, the rest of the team wakes to news breaking on the radio. David and Phurba have made it, but it's not all good news. As the team watches events unfold through telescopes, a Japanese climber becomes the first of many deaths on the mountain this year. "We may be passing him on the ropes," says Tim with a shudder. Then, other casualties begin to stumble into ABC – a British solo climber arrives frightened and confused with high altitude pulmonary edema and a Japanese climber staggers into the medical tent with frostbite.

The team members watch with mounting concern as the death toll grows. In five days' time it’s their turn to take on the world’s deadliest mountain and conquer their own fears. "Of course people are worried that they will not come back down in one piece," says Rod. "If you are not worried, there is something wrong with you."

On the summit, David and Phurba are in unexpected trouble. The bad weather has meant no one has been able to climb the mountain from the south side, and therefore no safety ropes have been fixed for their descent. They'll have to break trail themselves and rope themselves together in the hope they can save each other if one of them falls. To make matters worse, neither of them has ever been on the south side of Everest. As they drop behind the summit onto the South Face, they fall into the shadow of the mountain – and radio silence. They are on their own.