THAT NIGHT IN BARILOCHE, the address Ayala had given me looked dubious. The building was a half-abandoned office block. The lobby was deserted. The elevator shuddered and then stopped between floors four and five, where some plumber-commandos out of the movie Brazil crawled aboard. On ten, the highest floor, I found myself in a dank, silent hallway, following numbers beneath burned-out bulbs. At the end of the hall, at the last door, there it was: 1004.

Inside was a funny, five-dollar paradise. Hostel 1004, as I finally learned it was called, was beautiful, with wraparound views of Lake Nahuel Huapi and the Andes from a carpeted lounge. There were two big fireplaces. The rooms were nice, with good bunk beds, and the bathrooms were clean. At a sun-drenched picnic table on the terrace, two Israelis were quizzing a Frenchman about the skiing in Bariloche. It was the best crash pad I'd ever seen.

Here was a reason to follow the Book. The Book knew. Though Hostel 1004 does appear in guidebooks, you would never have

Now I just want to say that a good experience is not where you go, but inside of ourselves. I've had some of my best experiences fucked out of my brain, and damned superb they were. —Anonymous, El Lobo

picked this one dive from the foolscap wilderness of low-rent listings. But as they had throughout history, the Israelis passed knowledge along, mouth to mouth, ear to ear. The Book learned what they learned.

"So where's the Book?" I asked. The manager, a rocker-tressed Argentinian named Juan, sucked in his breath. "We don't know," he confessed. They'd had a good volume, five years of entries kept up by Israelis and everybody else. But in October, when they were repainting the place, the Book had been shoved into storage, casually, only to disappear. (Indeed, on the message board, a huge note read "EL LIBRO?")

"A lost treasure," Juan said. But he didn't doubt that eventually the guests at 1004 would start a fresh one.

I couldn't doubt it. People would make the Book anew,

The Book shouldn't exist, yet it does, a counterintuitive survivor. If it shrank in one place, that was only because the wave had moved on. It was blossoming in some cheap hostel you and I have never heard of.

somewhere, somehow, because they needed it. The Book was an analog artifact in a digital age, diminished by Web updates and nomadic e-mail, but never obsolete. Back at El Lobo, Dorit had suggested that the Book's golden age might be over. "Before," she said, "the Book was like the Bible. Now, almost nobody asks for it." She had opened a cybercafé and encouraged her guests to post their entries on El Lobo's Web site, www.lobo.co.il. "This is history," she'd said, slapping the soft brown paper.

If so, then it is history that's still being written. The Book shouldn't exist, yet it does, a counterintuitive survivor like the underground postal system in Thomas Pynchon's The Crying of Lot 49. And if it shrank in one place, like El Lobo, that was only because the wave had moved on. It flourished in four volumes at a laundromat in Costa Rica; it was on the rise at the House of Fun, in Lima; it was blossoming anew in some cheap hostel you and I have never heard of.

A few days later I set out, south as always, but alone this time. I never saw Avi or Elad again, not in Patagonia or anywhere else. Elad would write from various ports of call: Boulder, Israel, Manhattan. South America had been great, he reminisced, calling the experience "the first time I was really free."

With the clarity of distance and time, the Israeli-Palestinian conflict suddenly seemed "silly, unnecessary," he wrote. Although Israelis had every material advantage, they were still "blind," trapped in a narrow view of the conflict, unable to imagine a way out. "If that is the situation in Israel," he said, "just imagine what is going on in Gaza and the West Bank," where Palestinians lived in an even narrower bubble. Elad suggested sending leaders from both sides on a six-month world tour, just to open their minds.

The last time I heard from Elad, he was on his way to India. Maybe he'd see me, here, or there, or somewhere. The trip wasn't over yet. There were always more pages in the Book to fill.