“Those who go out in search of knowledge will be in the path of God until they return.” —Al-Tirmidhi, Sunan, 39: 2. (In Muslim Travellers: Pilgrimage, Migration and the Religious Imagination,edited by Taylor and Francis.)

We encountered human footprints recently in the desert. An astonishing sight.

We were inching slowly north toward Haql, to the brow of the Levant, traversing an oceanic white plain that burned at the edge of a true sea—the Gulf of Aqaba. Nothing stirred but the wind. We trod on dust born at the origin of time. And then the track appeared: a human being walking east without camels, alone. Ali al Harbi, my translator, suggested I take a photograph. But to what end? The prints could have been anyone’s, even our own. They would vanish tomorrow. (As would ours—brushed away by the eternal broom of the northerlies sweeping down from Syria, from Palestine.) Yet the track’s power—its ability to arrest our attention—spoke to the paradox of Saudi Arabia. A famous desert once inhabited by a legendary people—the Bedouin—a fabled landscape now almost completely abandoned, stripped by the advent of cities, petroleum, cars. In 700 miles of trail, these were only the second footprints we had seen.

Walking through the Hejaz has been often like moving through a dream. Through a society convulsed and catapulted from the black goat hair tent to glass skyscrapers. The hallucination of neon-lit truck stops with Pizza Huts. (Saudis staring out, through window glass chilled by air conditioning, at an American leading two camels through blast-furnace heat.) The profound sense of isolation, apartness. The workaday ritual of lives steeped in faith. (“Excuse me, Mister Paul, while I go pray.” ) The ache to be understood despite the walls and veils and visa restrictions. The mutual wonderment. The improbability of it all. The dizzying void of history.

On the day of the footprints we camped on the naked plain.

I stood atop a small rise, trying as I often do to capture a cell signal. And in the deepening dusk, which in the desert appears to seep up from the land itself and not descend from from the sky, I heard distant voices. From my campsite: Ali al Harbi, Awad Omran, and Hassan al Faidi, my walking team. And from somewhere out in the thickening gloom: the parked Coast Guard vehicle that had been shadowing us for miles. We had been under loose surveillance for weeks.

“Why are you following us?” I asked the soldiers.

“We are protecting you.”

“From what?”

“We are protecting you.”

In the West, it is the incessant babble of advertising, of television, of trivial information, text messages, and phone calls that mask what is truly important. In Saudi Arabia, old-fashioned silences still carry freight.

I descended to camp in a foul mood. But as I came closer to the hissing gas stove, to the tarp spread on the sand, I heard my friends laughing. The presence of soldiers did not disturb them. They were telling stories, lying on their elbows, sipping tea. And within perhaps 30 steps, my mood reversed. My heart had turned over. These fellow travelers were my Saudi Arabia. Not the desert. I was glad we were together. Even our watchers. We all were journeying together, as we always do.

Today I said goodbye to Ali, Awad, and Hassan, who will remain friends for life. I said goodbye to my logistician Saeed al Faidi, who will host the brave camels Fares and Seema at his desert farm outside Yanbu until their last pampered days. I said goodbye to the deputy governor of Haql, who permitted me to walk 500 yards across the international border between Saudi Arabia and Jordan—a trek, apparently, that has never been attempted before. I said goodbye to the Kingdom of Saudi Arabia.

At the Haql border post, the team that made my Hejaz trek possible: From left, Saeed al Faidi, Hassan al Faidi, Ali al Harbi, and Awad Omran. Photograph by Paul Salopek

Twenty-seven dry miles separate Haql from Aqaba, Jordan. My only fuel was one small bottle of guava juice.

I stepped from the desert doorway with nothing except the clothes on my back and a shoulder bag filled with notebooks—blue-lined paper pads bound together with rubber bands and stained with my sweat, with camel shit, by smears of my own blood. The pages crazed with jottings about devastating heat. The bearings for remote wells. Inked maps of pilgrim roads. The divinations of Bedouin fire cures. Mile upon mile of sentences from an austere kingdom still largely closed to the world. I walked along the concrete highway and spotted the first alcoholic artifacts I had seen in seven months (bottles, cans), past a large potash mine, and up the wrinkled coast to a tourist town. I saw women in colorful sarongs. Some drove cars. Nobody watched me. I floated out of a desert wadi like windblown trash. I found an ATM. I asked directions to a posh hotel with knockoff Mies van der Rohe tubular furniture in the lobby. Men gave camel rides to tourists outside.

Near Aqaba, the first mile in Jordan. Photograph by Paul Salopek

“And where”—asked the clerk, without the least curiosity, as I signed the paperwork—”are you coming from, Mr. Salopek?”