A bright morning during the last week in August, Reinhold Messner left his summer home, a spectacular 13th-century castle in the German-speaking part of northern Italy, and headed by car for the town of Sulden, about an hour west. The Adige River flashed through groves of apple trees, while high above the valley dairy farms sent their milk to market on cable cars.

In three weeks the greatest mountaineer of his generation, maybe the greatest of all time, would be 60. Messner seemed in fine shape: trimmed beard, cloudless blue eyes, only a dusting of gray in his dark, shoulder-length hair. Climbing had cost him the tips of several fingers, along with seven of his toes, but his hairless hands looked eerily smooth and unscathed, as if he had worked all his life at a cosmetics counter. "My knees are going," he conceded when I asked about the ravages of age. "But I still have the same energy I had at 22. Three weeks ago with my brother Hubert and a guide I climbed a new route on the west face of Mount Ortles. I was nervous at first, but I calmed down. It was good to discover the instinct was still functioning."

Messner's career spans a hundred expeditions and 3,500 rock climbs. He was the first to top all 14 of the world's 8,000-meter summits, and the first, with partner Peter Habeler, to scale Everest without the use of bottled oxygen. In 1980 he again climbed Everest without bottled oxygen, but that time he did it solo, taking a never-before-climbed route and finishing in only four days – arguably the most astounding feat in mountaineering history. He set new technical standards, pioneering fast solo ascents – often on new routes – of Himalayan giants that had previously been climbed only by huge teams using slow siege tactics and armies of porters. And he disdained supplemental oxygen in an era when it was considered suicidal to climb without it.

But despite the famous mountains he's conquered, Messner has been haunted for the last 35 years by a relatively obscure Pakistani peak called Nanga Parbat – not because it was his first 8,000-meter summit, but because his younger brother Günther died during the climb. Questions and accusations about Günther's disappearance have plagued Messner ever since. Did he abandon his brother just below the top of the mountain, as some have charged? Or was Günther caught in an avalanche closer to the base, as Messner claims?

Since the 1970 tragedy, Messner has returned to the mountain five times, as to a wound that wouldn't heal. And he's revisited the incident repeatedly in the dozens of books he's written about climbing. But the controversy still remains unsettled; in fact, it has intensified in recent years. So once again Messner is planning to go back. Later this year he will return to Nanga Parbat to hunt for Günther's remains, hoping to set the record straight.

Driving to Sulden, Messner described a very different journey, a traverse of the Gobi desert he completed in July. "Crossing the Gobi was a real milestone for me," he said. During the trip the past was clearly on his mind, and he found himself thinking about his childhood. "Before my mother died in 1995 she was always telling us not what she did in the last three weeks but what had happened in her childhood. I remembered a time my parents brought me and my older brother Helmut into the woods. He was six and I was three or four. We became tired, and Mother and Father had to go higher. They said, 'You wait here under this tree.' My brother began to cry. I asked him, 'Do you know the way home if Mother and Father don't come back?' He said, 'No.'"

Messner falls silent, as if lost in the idea that the primal loneliness he felt on expeditions might be linked to a small boy who didn't know if Mother and Father were coming back. He was the second of nine children born to Josef and Maria Messner – a Roman Catholic family, eight boys and a girl. They lived on a farm in the sheltered village of Villnöss, northeast of Bolzano. Josef, who died in 1985, was a school headmaster and an enthusiastic climber. He introduced Reinhold to the area's cliffs, belaying him up the Geisler peaks on a hemp rope when Messner was only five years old.

But Reinhold was much closer to his mother, and relations with his father were often tense.

"He was a soldier in the army when he was 20," Messner says. "They all saw brutality they could not imagine, and it was not allowed for them to speak about it. They kept it inside, and part of them became aggressive."

In The Naked Mountain, his latest and most detailed account of that fateful summer on Nanga Parbat 35 years ago, Messner described coming home as a teenager to discover 12-year-old Günther cowering in a dog kennel: "Our father, during one of his fits of rage, had thrashed Günther so badly with the dog whip that he could no longer walk. On that day we not only became friends, Günther also became my climbing partner and soon he was climbing just as well as I was. We began to talk about trips out together and started to view our climbs as little escapes. We wanted to get away, away from our authoritarian father and away from the injustices of this world."

Around a bend Sulden appeared, a cluster of chalets, cropped pastures, and stone walls under a lowering sky. The only hint of its wild setting was a rock-covered glacier descending from the clouds.Almost from the moment he staggered back alone, Reinhold Messner has been explaining what happened after he and his brother reached the 26,660-foot summit of Nanga Parbat, the ninth-highest mountain in the world. That summer Reinhold was 25, Günther 24. They were part of a 16-member team of experienced German and Austrian mountaineers that for more than a month had been stringing camps up the south face of the mountain, an unclimbed 14,800-foot wall known as the Rupal face.

Beset by bad weather, the expedition was close to calling it quits, but on the evening of June 26 Günther, Reinhold, and Gerhard Baur were in camp 5, at 24,100 feet, hoping conditions would allow one last try. Out of radio contact, they were depending on colored signal rockets fired from the expedition base camp to give them the forecast: blue for good weather, red for bad. Expedition leader Karl Maria Herrligkoffer had agreed that if the weather were doubtful Reinhold would make a fast solo push for the summit, leaving Günther and Baur to fix ropes in the couloir to safeguard his descent and to facilitate any future summit attempts by teammates ascending from lower camps. However, while the actual weather forecast was favorable, a red rocket was mistakenly launched from base camp.

It was the first of a series of deadly miscommunications.

At 2 a.m. on June 27, with the temperature around -22 degrees Fahrenheit, Messner laced his boots and set out in the dark, seeking a place in the pantheon beside his idol Hermann Buhl, the Austrian climber who made the first ascent of Nanga Parbat alone in 1953. According to his own account, Messner carried only a camera, some fizzy drink tablets, a bit of utility cord, and some dried fruit – no pack, no rope, no tent. He climbed by the light of his headlamp and the stars, glad not to have too good a view of the 12,000-foot void at his heels. He worked his way up the rock and the snow-covered ice in the Merkl couloir, an 1,800-foot gully named for a German mountaineer who died on Nanga Parbat in 1934. By midmorning, having made good progress, Messner glanced back and saw another climber speeding up the couloir alone. It was Günther. Messner waited, and when his brother finally arrived after a phenomenal four-hour effort, Reinhold asked, "How did you find the route?"

"Your tracks," Günther said. As planned, Günther had started fixing ropes in the couloir with Gerhard Baur, but Baur had returned to camp with a sore throat, and Günther, tired of untangling snarled lines, set out after his big brother instead. Although Messner confessed later that he was initially "irritated" that a partner might slow his progress, it seemed fitting that he and Günther were now together. They had been climbing as a team since they were boys, forging notes to get out of school on days of fine weather, and later riding together to the cliffs on their father's Vespa. On their first summit as a pair, the Kleine Fermeda in the Dolomites, they had only one helmet, and took turns wearing it.

In the afternoon they reached the summit ridge of Nanga Parbat. To the right was the Rupal face, the way they'd come up; to the left, the less steep but equally massive Diamir face – which had been climbed only once before. The awful nighttime cold had given way to draining afternoon heat. Every few steps they stopped to gasp for breath. Reinhold took pictures. They pushed on. About two hours before sunset they could go no higher. They pulled off their snow goggles, removed their mittens, and shook hands. Günther clapped his brother on the shoulder. Their first 8,000-meter peak! Many more were in store for Reinhold; Günther could not know this was his last.

About an hour before sunset they started down into what Messner would later call "the most difficult days of my life."

As they came down the ridge dividing the two great faces Günther began to lag behind, spent from exertion. Messner wondered if his brother was suffering from altitude sickness. Günther pointed with his ice ax to the less steep Diamir face to the west.

"We have to go down the way we came," Reinhold told him.

"Too difficult," Günther replied. "I'm so tired."

"But we'll be even more tired tomorrow. We have to lose some height before it gets dark."

"But not the way we came up," Günther said. "We have to find an easier route." And Messner did not insist they return on the route they had climbed. It was then that Messner remembered the red rocket. Bad weather would be coming in soon. "We needed to get out of there fast," he said. And so they took the Diamir side of the ridge.

Desperate for a place to bivouac, Messner decided they would head down to the Merkl gap, at the end of the Merkl couloir. During their summit bid, they had exited the couloir shortly before the difficult section at the very top, but he thought it might be possible to traverse back into the couloir from lower down on the ridge. If they could not traverse, they might be able to shout down to camp 5 for a rope, and then with help rappel into the couloir.

They picked their way down, found a hollow, and prepared to spend the night out in the open in below-freezing temperatures. They sat on their boots, shivering together with their feet wrapped in a foil space blanket. Günther began to hallucinate; before daylight he stood up and began to walk in a circle, moaning to himself.

Around 6 am Reinhold went to a nearby notch in the ridge and began to shout down the Merkl couloir. A bit later he traversed close enough to the couloir to spot the tracks he and Günther had made the day before on the way up. He realized that reentering without a rope from their position would be impossible. For two hours he shouted, "Help! We need a rope!" Günther remained back at the bivouac site below the crest of the ridge; when Reinhold returned Günther pointed out that the wind would probably have drowned the cries for help. Reinhold went back again to the ridge to look down the couloir and this time saw two figures coming up: teammates Felix Kuen and Peter Scholz. He was sure they were coming to rescue them. "Hello! Give us a rope!" Reinhold shouted when Kuen was about a hundred meters below his position on the ridge.

Kuen shouted back, "Were you on the summit?"

Reinhold screamed, "Yes."

Reinhold then thought Kuen shouted out, "Are you both okay?"

"Yes, everything's okay, Felix."

Later the puzzling exchange would be one of the pieces of evidence used to challenge Messner's account. Why would someone who felt himself and his brother to be in dire straits say yes, everything's okay? In The Naked Mountain, Messner explained: "Yes, we were okay. I had been shouting for help for three hours because we needed a rope, but otherwise everything was okay. Maybe I even said 'otherwise' – otherwise everything is okay – but I cannot be sure. I was so sure the two of them were coming up with the sole intention of helping us. And then it dawned on me they were intending to go for the summit. How were we going to get down now?"

Apparently another miscommunication. Kuen later wrote, "I didn't understand anything as the wind was blowing too hard over the ridge or maybe the blood was pounding too hard in my ears." Messner reported that Kuen had explained to him later that "he was convinced everything really was okay and that he was relieved to be able to carry on to the summit without having to worry about us."

Now, without a rope to get down the Merkl couloir or the strength to backtrack to their original route up the Rupal face, the brothers' lives were hanging in the balance. "The choice was simple," Messner wrote. "Attempt to descend, or die."

"I can't take another bivouac, Reinhold," Günther said.

So they began to climb down into completely unknown territory on the Diamir face, in what Messner would later call his "descent into despair." It was one of the most audacious feats in Himalayan annals: a full traverse of the mountain. Messner plotted the route as they went, comparing the vast terrain to what he remembered of photographs he had studied over the winter in Italy. "One of our companions," he wrote in The Naked Mountain, "was later to describe the descent as reckless and my decision as unreasonable and going against the basic principles of mountaineering. I still maintain that it represented the only alternative to certain death."

Down and down and down. They marched through the day and into darkness. Around midnight they bivouacked again, at about 6,000 meters, above the Mummery Rib, a prominent feature named for the English mountaineer A.F. Mummery, who had died attempting the Diamir face in 1895. Frostbite was starting to creep into Reinhold's feet. After a short rest Günther felt better, and they continued by moonlight. By sunup they were nearly down. The terrain grew easier; the route through the seracs was not hard to follow. Reinhold walked faster, trying to hurry off the face and onto the glacier before avalanches were unleashed by the morning sun. It was 8 a.m.

"Are we going to head down there to the right, between the seracs?" Günther asked.

"Yes," said Reinhold, certain the difficulties were over and the way to the bottom of the face was obvious. "It will be the fastest way down. We'll wait for each other at the first spring."

In another puzzling decision – given that he had spent the last 39 hours shepherding his flagging brother down the Diamir face – Reinhold took off. He had ranged out ahead the day before to scout the labyrinth of the face and then climbed back up to guide his brother down, but now the route was obvious, and he was convinced Günther would be fine on his own. When Mummery had come over the same stretch he hadn't even bothered with a rope. "I just kept on going, heading down between the ice cliffs," Messner wrote. "Günther would be fine. He couldn't miss the route now and he wasn't going to fall into any crevasses. The difficulties were well and truly over."

When Reinhold reached the bottom of the face, he slaked his desperate thirst with glacier melt water, and waited for Günther to show up. Then he began to hear voices. He hadn't eaten in five days. He called and whistled for Günther. Could he have gone another way? Anxious now, he began to search. Lead-legged, he retraced his steps up the now-slushy snow. Nothing. No tracks, no sign of crevasse falls, only mounting horror that something unthinkable had happened. Near sunset he stumbled upon the rubble of an avalanche and realized Günther must be buried somewhere beneath it.

In despair he shouted Günther's name over and over. He passed another endless night on the glacier. His toes were turning blue. He began to hallucinate, seeing visions of his mother in the kitchen of their home in Villnöss. He could see no reason to go on except "to let our parents and all others at home know what had happened, my mother above all."

The next day, according to Messner's account, he began dragging himself down on his injured feet. He staggered into the uppermost village of the Diamir Valley, and was eventually carried down the valley by some local men. Two days later, a week after he had left camp 5 on the Rupal face, he was reunited with his teammates 20 miles outside the village of Gilgit.Upon his return to europe, Messner prepared a report for the expedition leader, Herrligkoffer. Then in 1971 he published a longer account of the saga, accusing Herrligkoffer of incompetence. Herrligkoffer sued to enforce provisions in the strict contract the climbers had signed that gave him sole rights to the story.

Thus it seemed strange to some of Messner's former Nanga Parbat teammates when, in 2001, Messner was listed as the co-author of a positive biography of Herrligkoffer, a man whom he called "that despiser of mankind." And it was absolutely confounding that Messner, speaking at a Munich presentation that year in honor of the book's release, shifted his condemnation from Herrligkoffer to his former teammates, implying that Günther's death was the result of their negligence.

Former Nanga Parbat teammate Jürgen Winkler, who attended the presentation, recounted Messner's charges to me by phone: "He said some members of the expedition would not have minded if the Messner brothers did not come back from the Diamir Valley. This was so terrible that Gerhard Baur spoke up to say it wasn't true. I said the same thing. Later on the same evening we all went downstairs to have some bread and wine, and I took Reinhold by the shoulders and spoke to him directly and said, 'It's nonsense what you are saying!' He began to shout very loudly about the Munich [climbing] mafia. It was these two things he said that night that started the [media] avalanche."

Messner subsequently denied making the remarks blaming his teammates for Günther's death. But word of the allegations spread. The story got into the press, and two other expedition members, who had long harbored doubts about Messner's account of the traverse and Günther's death, were provoked to break what had been more than 30 years of loyal silence.

In May 2002 former teammate Hans Saler, from his home in Pucón, Chile, published an "open letter" to Messner on the Internet, refuting Messner's charge that the expedition had been unwilling to help the brothers either high up at the Merkl gap or low down in the Diamir Valley. "I am convinced that your brother would have reached base camp alive if you would have asked unmisunderstandably for help, assuming he was still alive. Would that not have been more clever and responsible of you than to risk the descent on the unknown [Diamir] wall that you described as uncertain? We all ask ourselves, 'What really happened to Günther? Where is he buried?'"

The main claim asserted by Saler and Max von Kienlin, a nonclimbing member of the team who had been one of Messner's closest friends, is that Messner's decision to go down the Diamir face was not born of emergency, or suggested by Günther in his fatigue, but a gambit Reinhold had planned and had openly discussed with members of the team. Günther's impulsive decision to follow his brother had jeopardized what the ex-teammates said was Reinhold's dream of making a solo traverse. In his lust for glory Reinhold put his ambition ahead of his brother's safety.

"What happened up there on the mountain," Saler wrote (he and von Kienlin both published books about the controversy), "was no case of murder and manslaughter, only a kind of moral failure. Ethical norms were simply overridden by ambition, which resulted from Reinhold's history, personality, and specific mentality."

Saler compiled a list of some 200 contradictions and inconsistencies in Messner's various versions of the descent. Among the most significant was the substance of the wind-tortured conversation at the Merkl gap, in which Messner apparently did not convey to Felix Kuen the gravity of his and Günther's situation. Kuen cannot offer his side of the story anymore. He committed suicide for unknown reasons in 1974.

Another major disagreement comes from the testimonies of Baur, Winkler, von Kienlin, and Saler, who insist that not only did Messner talk of the traverse, he actually had a black-and-white photograph of the Diamir face with him on the mountain. In an affidavit Gerhard Baur said, "In our base camp, Reinhold Messner showed me his picture of the Diamir face. On this picture he showed me which route he had planned to descend." Messner has denied having any such picture, and stated that his enthusiasm about traversing Nanga Parbat was just excited speculation.

A third bit of evidence, and perhaps the most unsettling, comes from the bottom of the mountain where Saler and von Kienlin witnessed Messner's reaction when he was reunited with his teammates. Max von Kienlin wrote: "[Reinhold] looks at me with wide open eyes, seems to sob and screams, 'Where is Günther?'"

Why would he say once, and then again – Where is Günther? – if he were all but certain, as he later maintained, that Günther was buried under an avalanche at the bottom of the Diamir face?

Saler speculated that Günther was exhausted but not yet suffering from altitude sickness, and preferred to return the way he'd gone up. Citing many sources, including Messner's account of his solo climb on the Diamir face in 1978, Saler argued that the terrain on the upper Rupal face was actually easier to negotiate than the terrain on the Diamir side. The brothers could have seen that the weather was good, red rocket notwithstanding. Günther would have been able to find a spot to bivouac near the entrance to the couloir, and then hope for help on the descent from Kuen and Scholz, who would be coming up in the morning. Meanwhile Reinhold, eyeing the prize of the traverse, would have descended on the Diamir side to the Merkl gap, where he would bivouac across the couloir from Günther. Thus he could have made sure his brother got down okay with the help of climbers coming up. Saler contends that Reinhold did exactly that, but that Günther, very tired, fell somewhere en route to his bivouac. It is likely he fell down the Rupal face, but he could have fallen down the Diamir face, because a stretch of the route between the main summit and the south summit sloped away to the Diamir side.

In other words, when Messner said "Everything is okay" to Felix Kuen around 10 a.m., he was actually alone, and had been up since daybreak calling Günther's name, wondering where he was. (Von Kienlin wrote in his book that Messner had told him this is what happened.) When Kuen asked Messner if he had been to the summit, Messner knew that Kuen had not seen Günther. Saler wrote, "He can now assume his brother is missing and he also knows that he will have to justify himself for this later and must answer the questions: Why did he allow his exhausted brother to descend alone? Why was he descending on the route to the Diamir side?"

Even more shocking is von Kienlin's claim that the story of Günther dying in an avalanche at the bottom of the Diamir face was not Messner's idea but von Kienlin's invention, which he offered to Messner as a way of explaining Günther's disappearance to Herrligkoffer after rejoining the team in Gilgit.

Messner accuses von Kienlin of faking the pages of his diary that purport to document the genesis of the face-saving cover story. "It's clear," he told me, "that for the members of the whole expedition, we disappeared for them. Just the fact that they didn't go to look for us in the Diamir Valley is proof that the traverse wasn't a possibility they knew about beforehand."

And then a bone came tumbling into the midst of the charges and countercharges. On an expedition to the Diamir face Messner made with his brother Hubert in 2000, one of the members of the team found a shinbone in the glacier near the spot where Messner claimed Günther had been lost. Hubert, a doctor, discounted the idea that it could have been Günther's after making a quick estimate of the size. Messner thought it might be the remains of a Pakistani climber who had died on the face, or perhaps even of A.F. Mummery. He brought it home and kept it in his library. When the skeleton of the Pakistani climber was later found intact, and the charges of Messner's ex-teammates were splashed all over the news media in Europe, Messner decided to have the DNA of the shinbone assayed. Initial tests at the Institute of Forensic Medicine in Innsbruck compared the bone DNA with DNA in cells swabbed from Messner's mouth and found a high probability that the DNA from each sample was from the same family. A few months later another test compared the bone DNA with genetic material from Messner's brother Hubert. The probability was even higher. The clinching evidence was the mitochondrial DNA tests.

"There is no doubt now," Messner said. "The first test said it was 60 times more probable the bone was from our family, the second one that it was 600 times more probable, and the last one showed there is no logical way to conclude that this is not our brother." But Saler has argued that the discovery of the bone, while eliminating the possibility that Günther fell down the Rupal face, tells nothing about how or even where he died on the steep ice of the Diamir face.

Messner sued both Saler and von Kienlin over their published accounts of the events. The case against von Kienlin is still in the courts, but last August the Hanseatic Higher Regional Court in Hamburg ruled that the publishers of Saler's book, Zwischen Licht und Schatten ("Between Light and Shadow"), had to revise nine of 24 contested statements, essentially saying that what had been presented as fact must be recast as perception.

Messner to this day seems bewildered by what motivated four of his ex-teammates to engage in what his court papers termed a "campaign of character assassination." He speculates that their actions were driven by "jealousy," "self-importance," greed for book sales, displaced guilt, or shame for not having done more to help when he and Günther were in dire straits. "A permanently bad conscience always looks for ways to relieve itself," he observed on his website. "They are parasites," he told me, in warrior mode. Von Kienlin is "a broken man," "a forger." Messner can't understand how journalists can take these "fairy stories" of his ex-teammates seriously.

If he believes his account of those hellish days is exactly what happened, and if it truly is, then no wonder the warrior is enraged. But in his wrath and vehemence, in his repeated and sometimes contradictory versions, it's hard not to see the handiwork of some displaced guilt of his own. He seems not to recognize that when he impugned his teammates' honor he precipitated the avalanche of challenges and rebuttals. Nor does he appear to be able to accept that Baur, Winkler, Saler, and von Kienlin might have come forward motivated not by jealousy or publicity but fidelity to what they believe is the truth. There is no mistaking the conviction with which Saler threw down the gauntlet in his open letter to Messner: "Why do you not show real greatness and speak about the truth? That would be up till now your unknown 9,000-meter summit."

Baur, for his part, told me in an e-mail, "I am convinced Reinhold Messner would have done anything he could to save his brother if Günther had needed his help. So I would never say that Reinhold 'sacrificed' his brother, as many journalists have put it. My only reproach against him is that he is trying to pass the responsibility to others and accusing former comrades in a completely unjustified way." 

Just a year after Günther's disappearance Messner went back to Nanga Parbat to search – unsuccessfully – for his brother's body. While he was there he dreamed that Günther came crawling out of the ice. He returned to climb the peak again in 1973 but was defeated. Consumed by the despair of an unraveling marriage, he made another bid in 1977, and again was turned back. In his book The Big Walls, published that year, Messner wrote, "I have had to defend myself against all the persecution and the many accusations that this Nanga Parbat traverse brought in its wake. I am well aware that it doesn't help at all to keep going back over the whys and wherefores of the accident. And I am no longer bitter about the outcome of the expedition, just unbearably sad that my brother never returned."

But he kept going back – to the whys and wherefores, and to the mountain itself, wishing, as he wrote, that he could be buried there alongside his brother. In 1978, newly divorced and having learned "that life can be borne alone," he soloed the Diamir face, "the greatest leap forward" in his career, he believed – bigger than the ascent of Everest without bottled oxygen he and Habeler had accomplished a few months earlier. Messner built a school in the Diamir Valley. In 2000 he returned to Nanga Parbat yet again and climbed a route on the Diamir face. His brother Hubert accompanied him up to 6,000 meters. After long conversations with Hubert he resolved to write again about the 1970 expedition. "Hubert said, 'I read your books but I didn't understand before. It's so brutal and terrible with all the avalanches and crevasses every day. Now I understand.' I asked him should I write about it again? And he said, 'Yes, put it down more exactly.'"

In 2005 Messner plans to return yet again to Nanga Parbat. "I think this trauma of his brother's death has been with Reinhold his whole life," said ex-teammate Jürgen Winkler. "I think the reason is that he doesn't know where his brother is and how he died. He just doesn't know." And there is the haunting and inescapable truth that in the end Messner did leave his brother. It may matter as a point of Alpine history whether they were separated high on the mountain or at the bottom when their ordeal was nearly over, but it is beside the point as a matter of the heart. Günther didn't make it home.The north face of 12,808-foot Mount Ortles was just beginning to rip loose of the clouds. Messner raised his arm toward the mountain on which he and Günther had put a new route when they were teenagers. "What you'll see when you come up is a black hill, green woods, and the mountain," he said as we entered the museum he's building in Sulden.

Museum impresario is not the second act you might imagine for a man who made his name as a visionary mountaineer, but Messner has an abiding interest in mountain cultures as well as in his own legacy. He also needs a place to put his collection of more than 3,500 artworks on mountain themes and climbing artifacts. The Sulden project was one of five mountain museums Messner was building in northern Italy. His first, housed in the tower of Castle Juval, where he lives in the summer, opened in 1993 and now draws 20,000 visitors at year.

"It's a cultural adventure for me, instead of a physical adventure," he said as he began making measurements with a folding rule in the basement of the new building. "At 30 I was not quiet enough inside myself. At 40 I was not rich enough. At 50 I was still hoping to change the world. Now I only want to tell stories. The museums are my way of telling stories, the common stories of climbing."

Around midday we found a table at the Yak & Yeti, the restaurant he opened in 1996. Waiters brought out a St. Magdalener red wine, plates of vegetables, and small delicious steaks of roasted venison and yak. Over coffee and krapfen – a Tyrolean tart – Messner reviewed the menu for a party he was throwing to celebrate his 60th birthday. Among the invited guests was Peter Habeler, with whom he had a well-known falling-out after Habeler suggested in his book about their Everest ascent that they'd agreed to fend for themselves if either of them got into trouble on the final pitches of the climb. Messner objected to the idea that he would desert someone who was in trouble in order to bag a summit. They mended their 20-year rupture when Habeler's girlfriend invited Messner to Habeler's 60th birthday party in the summer of 2002.

"I said to myself, 'Forget about the book. It's over,'" Messner recalled. "We spent a week together, doing five lectures in Zurich and Munich and Berlin and Vienna, and he will come in two weeks to my birthday party."

After lunch, while Messner conferred with an Italian landscape painter, I studied a brochure about his climbing career and his museum in Sulden. It was chockablock with quotes from Nietzsche, including one that seemed forlornly wishful in the shadow of his obsession with Nanga Parbat: "He who climbs high mountains laughs at tragic gestures." On the drive back, later that afternoon, Messner said, "I like Nietzsche. I quote him in many of my books. He was born 100 years before me." And indeed it was Nietzsche, not Freud, who was the daemon of Messner's daring life.

But Nietzsche's description of happiness that Messner had approvingly cited – "the feeling that once again strength has been increased, that once again an obstacle has been overcome" – was easier to embrace as a young tiger on a mountain than as a man growing older in a valley. The first day we met, as if it were a revelation, Messner had spoken of the delight he was taking in his two-year-old daughter Anna, appreciating her in a way he'd missed with his three older children. You couldn't help wondering if for all his will and self-sufficiency he was just as much a needy mortal creature caught up in forces he didn't understand as anyone else. There was something sad in what he had confessed to Habeler on Everest: that mountains were the only place where he felt at one with himself. Might not that alienated Catholic boy who didn't believe in God – the boy who warred with his father, and disdained authority, and was more interested in climbing the retaining wall of the village church than sitting inside at Mass – have performed the ritual mortifications of mountaineering as a kind of penance?

While we drove back to Juval I asked Messner how he found the enthusiasm to climb again after the tragic summer of 1970. He could not conceive of it for a long time, he said. "I came home in July and I was in the clinic in Innsbruck until September. I could not hike again until 1971. I was very quiet. I thought, Now I'm no longer a good rock climber. But I felt that the death of Günther gave me his energy. So for a time I had his energy and my own. In the Dolomites we had climbed the most crazy things. We had bad weather, we had problems, but we always escaped. We were lucky; we had the right instincts. All this gave us the feeling of being invulnerable. On Nanga Parbat all that changed. I understood that death is part of life, and life is finished by death. It's stayed with me forever. It's a strange feeling. I am responsible for my brother's death. I feel the guilt of having survived. People say, 'You should be happy. You survived.' But I have this feeling that it is not right that I am alive."

Before her death 10 years ago at age 83, Reinhold Messner's mother made her children promise to gather as a family at least once a year. They usually assembled around Easter or Christmas at a hotel, or sometimes at Castle Juval. Half the family lives abroad, half in northern Italy. But last August they met at a Catholic church in the village of Villnöss, where they grew up. The occasion was a funeral for the brother who didn't come home from Nanga Parbat. The last word any of them had from Günther was a letter he wrote shortly before he reached the summit: "And how is it back home? Have the schools broken up yet? Have Helmut, Erich, and Waltraud received our letters? Looking forward to seeing you all again soon." There had been a service for Günther in the same church in July 1970, but there was nothing to bury. "It was hard for the family to understand," Messner said. Indeed, his father, now 20 years in the grave, had blamed Reinhold for Günther's death.

Now they had a bone. The priest read from the Bible; Messner's brother Hansjorg, a psychologist in London, delivered a eulogy. And, unexpectedly, Messner found himself moved. "I had resolved my feelings about Günther a long time ago," he said. "But I found my brother's speech very intelligent and comforting." The remnant of Günther's life was returned to the earth in the church graveyard. And then, done with tragic gestures, the mourners had a picnic in a meadow.