They started out fast, reaching Camp IV in six hours, but 50 centimetres (20 in) of fresh snow slowed them down, and they reached the summit after over six hours of tough climbing. They descended on skis again, this time made even more dangerous by packed-down snow and the risk of avalanche. Despite this, they both made it safely back to Camp I in under 17 hours, whereas a normal expedition takes four to seven days.[1][2]