BY THE TIME OUR SCHEDULES matched up, four years later, Greg was so busy running the CAI that he no longer had time to attempt the Wakhan traverse. But he was still passionate about the journey, and delighted to help make it happen. In his former life he'd been a climber and adventurer—it was the path that had led him to aid work. Coming off K2 in 1993, weak and exhausted, he'd been taken in by villagers in Pakistan. Because of their kindness, Greg had promised to return the following year and build a school. Which he did. Three years later, he founded the CAI.

Greg believed that the only way to truly understand Afghanistan, with all its contradiction and complexity, was total immersion. Excited about the trek, he found a partner for me: Doug Chabot, director of the Gallatin National Forest Avalanche Center, in Montana, and a longtime Exum mountaineering guide. In an e-mail, Greg described Doug as "a tough, hardworking, easygoing, non-ego guy." Since we planned to attempt at least one virgin peak in the Wakhan, Chabot's avalanche experience "would be good life insurance." Our plan was to cross the Wakhan from west to east, using a four-wheel-drive van as far as we could, then going by foot or horseback.

The first time we all assembled was in Greg's dingy room in the Kabul Peace Guest House, a small hotel in central Kabul, in late April 2005: Greg, 47, comfortably attired in a dirt-brown shalwar kameez; Doug, 41, tan, trim, with big green eyes and an inimitable laugh; and Teru Kuwayama, 35, a New York–based photographer who had previously shot in Pakistan and Iraq. We'd be relying on Greg's contacts with regional leaders to secure safe passage through the Wakhan, but the real uncertainty was getting out of Afghanistan. Although we had visas for Tajikistan (and China, just in case), none of us knew anything about the borders at the end of the Wakhan. We could be stopped by Tajik guards and sent back, forced to retrace our journey in reverse. Or we could be arrested.

The corner of the Wakhan where Tajikistan, China, Afghanistan, and Pakistan meet is sensitive territory. On the China side, the Uighur, a Muslim Turkic population of eight million, are clamoring for independence. In Kashmir, Pakistan and India have yet to resolve their decades-old dispute over borders and ethnic governance. To the north, the former Soviet republic of Tajikistan is run by an unstable, authoritarian government, and the country is an integral part of the global opium pipeline. (As much as half of all opium produced in Afghanistan is exported via Tajikistan.) Islamic fundamentalist guerrillas have been known to infiltrate the region; if we encountered them—or were mistaken for guerrillas ourselves—it could get ugly.

Greg said he'd try to meet us within ten days in Sarhadd, in the middle of the Wakhan. He introduced us to 50-year-old Sarfraz Khan, his right-hand man.

"Sarfraz will be going with you," he said.

A tall, dark, mustached man stood up and extended a crippled hand toward me. "I am very pleased to meet you," he said. Over the years Greg had told me stories about Sarfraz. Born and based in the Chapurson Valley, in northern Pakistan, he had served as a commando in Pakistan's elite mountain force; while stationed in Kashmir, he was wounded twice by Indian troops. One bullet passed through his palm and paralyzed his right hand. He spoke English, Urdu, Farsi, Wakhi, Burushashki, and Pashto. He'd spent years traveling the Wakhan as a yak trader. In a land where everything was impossible, Sarfraz would be our indispensable, indefatigable fixer.

We spent several days in Kabul before heading north, shopping for supplies and exchanging dollars for bricks of Afghan banknotes at the Shari Nau market, and bicycling out to the now abandoned blue-domed Ministry of Vice and Virtue, whose Taliban enforcers had patrolled the city, whipping women for infractions as minor as revealing their ankles.

While the Afghan government has ratified treaties to improve women's rights, the country still has a long way to go to meet the standards it has set. A few days after we arrived in Kabul, the BBC and other international news sources reported that a 29-year-old woman named Amina had been buried up to her chest and stoned to death near Faizabad, the capital of northern Afghanistan's Badakhshan province, for alleged infidelity. According to the reports, 70 people from the community, including her husband and father, participated in the murder. In early May, 200 women gathered in Kabul to call on the post-Taliban government and Islamic leaders to oppose acts of violence against women, a first step on a very long, dangerous journey.

One day we visited the village of Lalander, south of Kabul, for a tribal meeting at a CAI school. It was a brand-new whitewashed, plumb-walled building amid helter-skelter mud homes. CAI schools are joint projects: The costs of construction and paying teachers are split between the CAI and the village. (Most of Greg's work is financed by private donations; the CAI receives no U.S. government funding.) With few exceptions, its schools are coed.

At the Lalander school, boys and girls were lined up in their Friday best to present Greg with wreaths of paper flowers. After the welcoming ceremony, he spoke at the jirga—the council of elders—which met inside the village mosque. Forty stone-faced, bearded men sat cross-legged on worn Afghan rugs. Greg asked for Allah's blessing, thanked the greatness and wisdom of Allah, asked Allah to guide the judgment of the jirga. Lalander, he said, would be recognized as the most powerful village in all of Afghanistan, because of its courage to build a school that both boys and girls could attend.

Later, Greg told me that some of the men at the jirga were Taliban. "My dream is to build a school in every village from Kabul to Kandahar right to Deh Rawood, the village of Mullah Mohammed Omar, fugitive leader of the Taliban."

As we were driving out of Lalander, Greg saw a man standing on a hillside near a pile of rocks and stopped our van. We walked over to talk to him. He was Gulmarjan's father; in June 2004, the boy had been blown to pieces by a land mine just a hundred yards from the half-completed school. According to the International Committee of the Red Cross, leftover land mines and ordnance killed or wounded some 847 people in Afghanistan in 2004; despite determined de-mining efforts, the carnage continues.

The man told us how excited Gulmarjan had been about going to school with his younger sister. As he spoke, he raised his arms in the air, as if expecting his son, alive and whole, to drop back into them.