TWO YEARS LATER AND STILL HE IMAGINED HIS BLINDNESS AS A TERRIBLE DREAM. He'd wake up and see again. The mountains. A wife whose face he knew only by touch. The sunrise. Everything. His last vision of this world was a dusty, darkened street in northern Baghdad while at the wheel of an enormous armored vehicle. The bomb was simple but lethal: a metal tube stuffed with explosives and capped with a concave copper disk. Powered by the blast, the disk transformed into a jet of molten copper that bored through the thick front passenger door. Shrapnel sliced through his friend Sergeant Victor Cota, then into him. Metal punched through his right temple, ruptured his eyes, gouged holes in his left thigh and right biceps, and mangled his left forearm. Face crushed and body scorched, he was covered in so much of Cota's blood that fellow soldiers thought he was dead, until he stirred from unconsciousness and wiped his face. Cota died in the truck, and Private First Class Steve Baskis woke up a week later in Walter Reed Army Medical Center to more pain than he'd ever felt and a doctor telling him he'd never see again. Yet he carried an optimism many couldn't understand. "I just love living, more than anything," he'd often say.

Before the deployment, his father made him promise that he wouldn't give up on life if he came home broken. So he learned to navigate a darkened world, ran in the Chicago Marathon and finished a half Ironman triathlon. He married a specialist in blindness rehabilitation and trained for the Paralympic cycling team. Baskis knew many wounded who'd become mired in desolation and anger. That wasn't him. He pushed and suffered and didn't quit. But now, as he gulped thin air and tripped and stumbled over rocks, the frustration swelled, and he wondered whether the final 2,000-foot ascent might break him. "I'm not going to make it if it's like this all day," he said. "I don't know if I have enough in the tank."

Beneath Baskis, several more climbers whose bodies had been battered by war were scattered on rope teams along the rock slabs. They'd had legs taken by explosions and crashes, brains rattled by bombs, and spirits hammered by loss and fear and the disorienting journey home from the battlefield. Those moments, the worst of their lives, had brought them here: working up the side of 20,075-foot Lobuche in Nepal's Himalayas, hours before dawn. For some it was their first trip to a foreign country not at war. They climbed alongside their expedition teammates—ten mountaineers who had scaled Everest in 2001, including Erik Weihenmayer, still the only blind person to summit that peak. Weihenmayer and his friends, many of whom had since become professional mountain guides, wanted to commemorate the climb. Leading ten injured veterans up Lobuche, in Everest's shadow, seemed an appropriate parallel. "An expedition has the ability to renew you, to renew your soul," Weihenmayer had told the veterans several days earlier in Kathmandu. "I've been on dozens and dozens of expeditions, and I've died and been reborn on every one."

The two groups had far more in common than each had first imagined. Usually, the language of war translates crassly to athletics. A playing field is not a battle­field; athletes are not warriors. But mountaineering approximates many elements of soldiering—a team trained to operate in extreme conditions straining toward a coveted piece of ground as the world falls away, until life is reduced to a small pocket of space and time. Death lurks in both as well, from an avalanche or a buried bomb, a misplaced step or a mortar barrage. I had served two tours in Iraq as an infantryman, and as we prepared for the summit push the night before at our 17,000-foot-high camp, the mood was electric, nervous, and giddy; it reminded me precisely of the energy before a mission, the mix of joking and seriousness, rechecking gear and rehearsing plans. I could have been back in Baghdad.

At least bombs weren't a concern; just breathing was hard enough. "I can't believe how much energy it takes to talk," a marine named Dan Sidles told me as we pawed up the slabs. There was little conversation anyway; most of us retreated inward, searched for purchase on the rocks, and tried to find a rhythm to our steps and breaths.

But near the front of the column, the slabs steepened and Baskis's optimism dimmed. He tapped and scraped his trekking poles against the rocks, probing for solid ground and for voids where he might step into nothing. His atrophied left hand, with its shredded nerves and blood vessels, ached in the cold. After the slabs, we would have another 1,500 vertical feet of snow and ice before he reached the summit—a summit Baskis would be able to stand on but not see.

He smashed his knee into a boulder and pain rocketed through his leg. "I don't want to go on," he said. "I want to turn around."

"This is no longer about you," said Jeff Evans, a few feet below him. Evans was the leader, the owner of Mountain­Vision Expeditions and a part-time physician's assistant from Boulder with 20 years of experience at high altitude. He recognized Baskis's problems as mental, not signs of altitude sickness or potentially fatal cerebral edema. Baskis needed a push. "You're doing this for all the men and women who have been injured," he continued. "You need to man up and do this."