It was morning and bright, and Reinhard Grubhofer, depleted and dehydrated, hoisted his body over a crest and rose uneasily. There, from the summit of Mount Everest, he could see everything. How the earth curved gorgeously in all direction; how wisps of clouds sailed beneath his boots. The view—out beyond his worries—was beautiful. But closer at hand, he could see trouble taking shape.

He could feel it, too, shuffling with a dozen other climbers onto a slim patch of ground roughly the size of two Ping-Pong tables. The space was crowded. Shakily, Grubhofer held up a small flag and posed for photos with his climbing partner, a fellow Austrian named Ernst Landgraf, who'd made the slog to the summit uneasily. It had been a brutal day. Their 13-man party had awoken at eleven the previous night and trudged through the darkness up the icy incline of Everest's north side. Along the way, the temperatures dipped to well below zero. At some point, the water bottle that Grubhofer packed had frozen into a solid brick. He was thirsty and exhausted. But he tried not to pay attention to any of that now. After weeks of waiting and years of planning, Grubhofer had made it. It was 9:30 a.m. on May 23, and a less experienced climber might have thought that the hard part was over. Grubhofer knew better.

As he jockeyed for a place to stand at the top of the world, his Sherpa's radio came alive. Kari Kobler, the founder of the Swiss mountaineering agency that had organized Grubhofer's expedition, was radioing urgently from base camp. Bad weather was moving in fast. They had to descend, quickly.

Grubhofer looked down toward Nepal and could see gray clouds sweeping across the southern face of the mountain. There was something else down there too: a line of a hundred or so climbers in brightly colored suits snaking up the side of the mountain. The crowd seemed incredible—like a bag of Skittles had been scattered down the slope. On the north side, Grubhofer knew, more climbers were tracing his trail up the mountain from Tibet too.

He hopped off the summit and crossed two windswept snowfields, digging unsteadily into the crust with his crampons. Whenever Grubhofer encountered somebody ascending the mountain, etiquette forced him to unclip himself from the rope to step around the climber. Each time he did so, he was aware that a gust of wind or a misstep could send him hurtling to an uncertain fate.

Grubhofer had tossed his goggles after they'd frozen in the night and now was wearing Adidas sports sunglasses, which fogged over constantly, requiring him to remove his down mittens in the cold to clean the lenses—a tiny reminder of the multitude of dangerous unpleasantries and unforeseen challenges that crop up on Everest.

“For God's sake,” another climber exclaimed, raising his arms in disgust. “Why is she not moving?”

None of this was new to Grubhofer. A wiry 45-year-old with a thatch of reddish-blond hair, he'd taken up mountaineering 15 years earlier at 30. That's when Grubhofer, depressed following a divorce, vowed to restart his life. He set out for the Himalayas and scaled 21,250-foot Mera Peak in Nepal. “I was not fit enough, but it got me hooked in,” he recalls. Over the following decade, Grubhofer ticked off three of the Seven Summits—the highest peaks on each of the seven continents.

Everest would be his fourth. He took his first shot in 2015, but the adventure was cut short. He was dug in with his team at 21,300 feet, at what's known as Advanced Base Camp, when an earthquake hit the region, setting off an avalanche that killed over a dozen people at the Nepalese base camp. Grubhofer's expedition was untouched, but no one from either the Tibetan or the Nepali side of Everest summited that season.

Returning to the mountain hadn't been cheap. Grubhofer, who works for a sightseeing company in Vienna, paid $65,000 for a package that included travel to and from Tibet, visas, guide and Sherpa fees, and the $11,000 permit issued by the Chinese government. Reaching the summit this time around represented a special kind of thrill, but he refused to celebrate until he was safely down the mountain. Late in the morning, as he made his way along the crowded trail, a fog rolled in, the wind whipped up, and snow began to fall.