DEATH AND IMPREGNABILITY have always been great motivators, of course. Not long after the Italians achieved their victory over K2 in 1954, India and Pakistan plunged into an extended period of fighting over their northern borders and closed off the central Karakoram; it was not until 1975 that foreign expeditions were permitted to return. Two years later, a 52-man Japanese expedition with 1,500 porters laid siege to K2, scaled the Abruzzi, and posted the second summit. A year after that, in 1978, an American team led by Jim Whittaker (the first American climber to summit Everest, in 1963) finally succeeded. Four men—Wickwire, Ridgeway, John Roskelley, and Lou Reichardt—made it to the top via a new route on the northeast ridge. The '78 expedition ushered in an era of breakthroughs on the mountain, including routes along the west ridge (Japanese-Pakistani, 1981), the south face (Polish, 1986), and the south-southwest ridge, which was summited that same year by Peter Bozik, a Czech, and two Polish climbers, Wojciech Wröz and Przemyslaw Piasecki.

K2's reputation as the most difficult and dangerous of the world's 8,000-meter peaks is surpassed only by the irrational pull it seems to exert upon climbers. No one understands this better than Wickwire, whose obsession very nearly cost him his life. When he completed his push for the top late on the afternoon of September 6, 1978, he was stranded on the summit face without a tent or sleeping bag as night fell, forcing him to endure 50-mile-per-hour winds and temperatures that plunged to minus 25 degrees—the highest solo bivouac up to that point.

"It was the only time in my climbing career that I really did let it all hang out, in the sense that I was going to get there no matter what," says Wickwire, who came down with pleurisy and had to have a piece of his lung surgically removed when he got home. "But I had this 20-year preoccupation with K2 in my dreams, and those dreams simply were not going to be denied. That's the power, the magnificence, of K2."

That magnificence can take strange forms. Weeks before he summited, Wickwire was descending with Roskelley to Camp 3, on the knife edge of the northeast ridge, when he witnessed the Specter of Brocken, a rare play of light in which a climber's silhouette is magnified and cast into the center of a cloud, sometimes surrounded by a double rainbow—two perfect circles, one inside the other. "That was the only time I've observed it in over 40 years of climbing," he says.

It was along this same ridge that Roskelley and Ridgeway found themselves enveloped one afternoon by a flock of orange-and-black butterflies that had wafted up on air currents. "They were everywhere," says Roskelley. "The world suddenly turned into this beautiful, orange, flapping mosaic of color."

Such moments can occur on any great mountain. But as commercialization threatens to overrun the highest peaks, these experiences become more elusive. K2's tendency to yield such ephemeral encounters partly explains why it draws a different type of climber than Everest—a climber who not only commands superior skills but harbors a deeper reason for wanting to be on the mountain. Greg Mortenson, who attempted K2 in 1993 after his sister, Christa, died at 23 of epilepsy, got as far as 25,000 feet but had to forgo his own summit bid to help an exhausted companion descend safely to base camp. Still, he has no regrets.

"I could have gone to Everest," says Mortenson, who went on to found the Central Asia Institute and spend the next decade building schools for young girls throughout northern Pakistan. "K2, however, seemed to better exemplify the freedom of Christa's spirit and my anger—my angst—over her death at a young age. On K2, you can't pay a guide service $65,000 to get you to the top. On K2, you need the experience, the skill, and the stamina to climb without these resources. Everest is a mountain for those who just want to climb to the highest point on earth. But K2 is more about philosophic heights. It's about purity, clarity, and being humble."

Perhaps no one fuses these elements more eloquently than Dr. Charles Houston, who led two of the earliest American attempts on K2. One morning, almost 24,000 feet up the Abruzzi Ridge during his second attempt, in 1953, Houston looked out of his tent. "It was about sunrise," he told me, "and the air was just filled with ice crystals. It wasn't snow; they were tiny, tiny ice crystals, and they were red and yellow and green and purple—all the colors of the rainbow. There were trillions of them, shimmering against the blue and black sky. It was a gentle and beautiful thing. And unforgettable."

This coming from a man who endured some of the most terrifying hardships on K2, and whose ordeal in 1953 has come to signify, more than any other, what it means to fail with dignity.