New Delhi, Oct. 18 -- It's a preposterous plan. Still, if you do get up, it'll be the hardest thing that has been done in the Himalayas." -Sir Chris Bonington, 1975.

On 15 May 1982, two British climbers set out from the Advance Base Camp (around 6,200 metres) on the north side of Everest to make a bid for the summit by the unclimbed Northeast Ridge, through the jagged Pinnacles. Two days later, while scanning through a telescope in the shadowy light of dusk, expedition leader Chris Bonington along with climber Adrian Gordon spotted two tiny figures on the crest of the ridge, moving painfully slow at an altitude of around 8,200m.

The two climbers, Peter Boardman and Joe Tasker, slowly disappeared behind the ridges of the Second Pinnacle,...