THE AFTERNOON I STUMBLED across the human leg bone at the bottom of K2, it was one of those flawless days you almost never see in the Karakoram. The light was radiant, the wind was calm, and the air at 16,000 feet—sharp and clear as etched glass—seemed to lift and intensify the hulking black mass of the world's second-highest mountain, which erupts in a single, unbroken thrust to its ice-armored 28,250-foot summit.

It had taken the better part of two weeks to get here, the heart of the high peaks in the Pakistani region of Baltistan, 800 miles northwest of Everest. When I arrived in late summer, the tail end of K2's climbing season, there was only one team left on the mountain: Hector Ponce de Leon, a 36-year-old Mexican climber who has summited Everest from both the north and south sides; his fiancée, Araceli Segarra, a 33-yearold Spanish alpinist who doubles as a fashion model in Vogue and Elle; and Jeff Rhoads, a 49-year-old American filmmaker who has worked as a mountain guide in Utah. The group would eventually be turned back by exhaustion and bad weather, 4,300 feet short of the summit.

K2 base camp—a lunar landscape of shattered rock sitting atop a river of moving ice —was all but deserted, with only a few Pakistani porters and an American woman named Jennifer Jordan. A 45-year-old journalist and filmmaker, Jordan had been in camp since June, monitoring the progress of Rhoads, her boyfriend, and working on a documentary about the five women who have summited K2—not one of whom, she pointed out, is alive today. We talked a bit about the history of K2, a subject Jordan has studied deeply, and then she asked if I might like to take her "tour of the dead."

"It's kind of like a bread mixer," Jordan observed as we picked our way around thin crevasses and frigid pools of Windex-blue meltwater. "The worst of the violence is the avalanches, but there are also the years of tearing and crushing in the glaciers. The movement churns them up in summer, back down in winter. Appendages get torn off in the disgorging process. When they surface, they're almost all headless, because that's the weakest link in the body. Mostly you find legs—very few arms."

The summer of 2002 had been unusually warm, so the dead had risen in large numbers. Six weeks earlier, Jordan had uncovered traces of Dudley Wolfe, a wealthy American playboy-cum-mountaineer who in July 1939 was stranded at 26,000 feet on the southeast ridge and vanished, along with the three Sherpas who tried to rescue him. They were the first climbers to die on K2. Jordan found some of Wolfe's equipment—including a mitten with his name on it—plus 30 of his ribs and vertebrae. Over 64 years, his bones and gear had traveled a mile and a half down the Godwin-Austen, averaging about four inches a day, before resurfacing.

At the moment, our attention was fixed on a small piece of delicate purple cloth that had recently emerged from the ice. "Wow!" Jordan exclaimed. "Now who would wear something like this up here? A woman." Jordan surmised it might be a piece of Alison Hargreaves's clothing.

In May 1995, Hargreaves, a gifted 33-year-old British mountaineer, completed the first undisputed female solo ascent of Everest without supplemental oxygen. Her intent was to summit K2 next, and then Kanchenjunga, the world's third-highest mountain, later that same year. But on August 13, after reaching the top of K2 in clear weather, Hargreaves and five other climbers were plucked off the mountain by a gale-force wind. "She was blown right off the summit ridge somewhere near that huge serac," Jordan said, pointing to a massive block of ice near the top and tracing Hargreaves's probable trajectory. "The thing is, we could be right on top of her."

We resumed walking, passing sundry bits of gear—a rack of pitons, an oxygen cylinder, a boot—until we reached the arm of a wool shirt lying on the ice. "This has got to be one of the Spanish guys," she said, referring to one of the climbers who died with Hargreaves. Earlier in the summer, Jordan had found his body, minus his head, and reburied him in a crevasse. "The skin was like burned leather," she said. "Dark brown, but not black. He hadn't been in the ice for long, because he still had his hands and his feet. Well... a foot."

You couldn't get any more nonchalant or dispassionate about human remains, and initially it seemed morbid and unseemly. But Jordan meant no disrespect. In fact, she was addressing something that sets K2 starkly apart from other great peaks in the Himalayas. All of these mountains have teeth. And all tender the seductive possibility that by venturing onto high, hard, unknown terrain, a climber can touch something within himself or herself that often proves elusive at sea level yet can be powerfully transforming when realized at altitude. On most mountains, this epiphany invariably goes hand in hand with reaching the summit

Not on K2.

The secret to K2 seems to reside somewhere inside the frozen ossuary at its base. As new climbers wade over the remains of so many who came before them, they are reminded of what it is to strive and to fail—horribly—on an 8,000-meter peak, and they confront the question of whether that failure, played out amid the elemental indifference of stone and wind and ice, can possibly have any meaning and inherent worth.

We were nearing the end of the tour when I blundered upon what appeared to be a hollow stick lying on the ice—an odd thing to find in a landscape without a single tree. I knelt to examine it.

"Oh," Jordan said. "Your first femur. Pretty gruesome, huh?"

The ends of the bone had been cut at such a sharp angle it looked like the job had been done with an electric saw. Bits of brown gristle clung to the sides.

"Welcome to K2," she added with a chilly smile. "There's nothing quite like it."