OUR JOURNEY CONFORMS to the pattern of a typical CAI road trip. Each day begins at dawn, when Mortenson and Sarfraz wake up in the same clothes they've been wearing for more than a week, surrounded by the clutter of their mobile office. First on the agenda: morning ablutions, which consist of Mortenson smearing hand sanitizer on his face and hair while Sarfraz scratches himself. Then they pop the cap on their jumbo bottle of ibuprofen, and each man selects two or three tablets as a pre-breakfast appetizer. "When we're going hard, we both go through about 12 or 15 of these things a day," says Mortenson.

At this point, one of the two men may put on the pair of eyeglasses they share (they have the same prescription) while the other steps outside with the toothbrush. (Yep, they share that, too.) One morning, I ask Mortenson to provide a list of everything else that he and Sarfraz use together.

"OK, let's see, we share our jackets, our razors, our soap, our socks, our shalwar kameez, our undershirts—"

How about underwear? Do they share that?

"Well, no, but …"

Mortenson hesitates, a sign that he may be concealing something. "Look, I'm not sure I want to reveal this, but there's no sense in lying about it, either. It turns out that I don't actually wear any underwear. I grew up in Tanzania, see, so I've kind of gone 'alpine style' for my entire life."

"What about you, Sarfraz?" I demand.

Sarfraz looks mildly embarrassed. "Alpine style for me, too."

"But one thing we don't share," Mortenson adds helpfully, "is our wives."

"No, that we definitely do not share," Sarfraz exclaims. "Wife sharing is a very bad idea!" "Although we're both really afraid of our wives, so I suppose you could say we share our fear," Mortenson adds.

"Actually," corrects Sarfraz, "I am afraid of my wife, of course, but I am also afraid of Greg's wife, too."

Tara Bishop, lodestar to the intergalactic mess that passes for Mortenson's life, is the daughter of Barry Bishop, a National Geographic photographer who was part of the first American ascent of Everest, in 1963. Tara met Mortenson in San Francisco in 1995, at an event in which Sir Edmund Hillary spoke about his own school-building efforts in Nepal. A few hours after laying eyes on Mortenson, she announced her intention to "kidnap" him. They were married six days later. Ten days after that, Mortenson flew back to Pakistan to finish building the Korphe school.

Bishop, who has a Ph.D. in clinical psychology, realized that she'd hitched her wagon to an unusual man. ("Greg is simply not one of us," she likes to say.) But sharing a life with Mortenson has resulted in twists that even she might not have anticipated.

Their modest home in Bozeman lacks a third bedroom, so Mortenson and Bishop sleep in the upstairs hallway. Meanwhile, their daughter, Amira, 12, and their son, Khyber, 8, have been forced to adjust to having a father who's often absent: Mortenson was away while his kids learned to walk, talk, and ride a bike. But the children have been treated to some exotic family vacations. Amira went to Pakistan for the first time at eight months, and on one special occasion she got a tour of the CAI's latrine-building projects along the Baltoro Glacier.

When Mortenson's on the road, Bishop keeps close tabs on him, dialing Sarfraz's satellite phone every day or two as we move from village to village, where Mortenson is barraged by requests for assistance. In a place called Khun Dhud, there's a man who wants money to set up a grocery store. In Ishkoshem, a pair of officials seek funds for a water-delivery system, while another is hoping for a hydroelectric plant. In Pigiz, the school principal needs desks and filing cabinets. The pleading is always polite, but the needs are endless: more books, more pencils, more uniforms, another school.

"We get proposal after proposal, and we have to say no to dozens of projects," Mortenson sighs one evening, while hearing a request from a group of local women who want him to pay for a new vocational center, where they'd be able to sew clothing and crafts to sell in the village bazaar. "Some of these people have traveled for days to present us with their requests. Others have been turned down by everyone else they've asked. And often we're forced to say no, too—like I'm going to have to do with these ladies right here."

Standing before the women, he turns to Sarfraz. "Your budget for the Wakhan is finished for this year, no?" he asks. This is true, but it's also a piece of pre-scripted theater that will lay the groundwork for a diplomatic denial of the women's request.

"Finished," Sarfraz confirms while pulling out his phone, which is ringing. He glances at the number and passes it to Mortenson, handling it as if it had spontaneously caught fire. It's Tara Bishop, calling from Bozeman.

"Oh, hi, sweetie!" Mortenson says. He listens a moment. "Well, right now I've got some women who want a vocational center. I've got like 20 of them surrounding me, and they've got this really feisty leader, but I'm afraid we're gonna have to say no, because … Oh. All right, I promise. Yes, sweetie. Bye now."

His next words, directed at the women, are translated by Sarfraz: "Wife-Boss says we must somehow find the funds for your vocational center. Wife-Boss also says that you should consider using your vocational center to start a book club—"

Sarfraz's translation is cut short by yet another phone call. This time it's Suleman Minhas, the CAI's operations manager for Pakistan, ringing from Rawalpindi to work out details of an "emergency" that arose earlier that day.

The man with no underwear, it seems, has been summoned to have a cup of tea on Sunday afternoon with General Pervez Musharraf, the president of Pakistan.

We have 72 hours to get to Islamabad.