After a bivouac high on the peak, the pair continued their descent the following morning but then Simpson fell from an ice cliff on the North Ridge of the mountain, breaking his right leg and heel.
To continue the descent, Yates then used their two ropes tied together (total length 300 ft (91 m)) to lower Simpson down the mountain in stages in deteriorating weather conditions.
However, although the pair had almost descended to the relative safety of the glacier, Simpson went over an unseen cliff edge as he was being lowered, which meant that he was hanging free with only Yates's hold on the rope to prevent him falling.
The following morning Yates completed his descent to the glacier and being unable to find Simpson he concluded his companion must have been killed, he returned to base camp that day.
Yates' initially received some criticism for cutting the rope from some not in possession of the full facts relating to his rescue of Simpson.
[7] Yates commented that after he moved away from Sheffield he had 'hardly seen Joe (Simpson) for nine years' until they went to Peru to film some scenes for the Touching the Void documentary.
The first, Against the Wall, is about an expedition to climb a new route on the Central Torres del Paine in Chilean Patagonia and was short-listed for the Boardman Tasker Prize for Mountain Literature.
[11] His most recent book, The Wild Within, describes expeditions to the Cordillera Darwin in Tierra del Fuego, the Wrangell St-Elias ranges on the Alaska-Yukon border, and eastern Greenland.