Speaking Italian that Charlie translated for me, Bonatti recalled the forced bivouac of July 30, 1954. "I could have gone down in the dark by myself, even without a headlamp," he said. "But Mahdi was out of his mind. Several times I had to keep him from running away.

"It took a long time to dig a ledge out of the icy slope. We sat very close together. Mahdi was too tired to take his crampons off, so I did it for him. Otherwise his frostbite would have been even worse.

"I spent the whole night looking at my five fingers to see if they were still there. Making up problems in my head to see if I could still think right. I kept banging my legs with my ice ax—that was before we knew it was a bad thing to do." (Pounding a frozen extremity can break blood vessels, exacerbating frostbite.) "It was as if one breath lasted the whole night."

In the wee hours, a sudden snow squall descended on the mountain, smothering the climbers in blowing snow. Three times the two climbers had to dig themselves out.

As soon as first light arrived, Mahdi took off, almost running down the mountain toward Camp VIII. "In the morning," Bonatti remembered, "I was a piece of ice. I didn’t have the strength to restrain him. All I could do was put on his crampons. My heart was beating fast as I watched him go. Then he reached a flat area, and I knew he was OK."

In the official account of the expedition, La Conquista del K2 (Victory Over K2), published the year after the ascent, team leader Ardito Desio tells a very different story from the one we were now hearing from Bonatti. Paraphrasing Compagnoni and Lacedelli, Desio writes that the lead pair never dreamed that Bonatti and Mahdi had bivouacked rather than descending. In the morning, when they saw Mahdi hurrying down the slope, "We were simply flabbergasted. . . . We thought of all the possible explanations except the right one. How could we suspect the truth—namely that two men had survived the rigors of a whole night spent in the open at an altitude of more than 26,000 feet?"

Both Lacedelli and Compagnoni claimed they never heard shouts in the night after the brief exchange that ended with Lacedelli’s request to leave the oxygen and go down at once. "Unfortunately," the pair reported, "the high wind made conversation very difficult."