The Chinese court, when it was told of the Buddha and when its mandarins were shown images of golden statues of his calming presence, was officially impressed: The religion swiftly took hold. Once it had become fairly well established, Chinese pilgrims began to make the long and dangerous journey to the religion's source, to see for themselves the fountainhead of their faith. Groups of translator-monks also began to travel, and they began to collect, translate, and disseminate among the Chinese the Buddhist texts, the sutras.

Four of these great translator-monks are remembered today in particular. One, an eastern Chinese scholar's son named Xuan Zang, is revered: His seventh-century adventures along the Silk Road, and to places in Nepal and India and what is now Pakistan and Afghanistan, inspired novels. His stories have found their way, even today, into Japanese manga and a 1980s cult TV series called Monkey. It was Xuan Zang who essentially inspired Stein's most ambitious journeying, and it was the monk's memory and the accounts of him that led Stein, inevitably, to the city which is the subject of this story. Marco Polo went to the desert, and Stein studied his writings, too; but Xuan Zang, who wrote with priestly precision, was his truest guide.

For the monk surely went to Dunhuang. Everyone did. The city is an oasis where palm trees and melon bushes rise out of the sand dunes, thanks to a river called the Daquan and a tiny body of water called Crescent Lake. My first sight of Dunhuang was much like Stein's, and quite deliberately contrived to be so.

I was well awake, after five bone-shaking hours in the Land Cruiser, and I decided to walk the last half mile. I got the driver to drop me at the base of a particularly fine-looking dune, and I climbed, slipping and sliding in the wind-carved sand, for a good thirty minutes, until I reached a summit maybe eight hundred feet high. My boots had made a squealing sound, a high, whistling note that followed me wherever I stepped: small wonder these have been called for centuries the Mingsha Shan, the Singing Sand Dunes.

The view from the top was unforgettable. The sky was clear, the eggshell blue of dawn. The dunes rose and fell and glittered, immense sharp-sculpted waves of pale yellow crystal, as far as it was possible to see. In the east, the huge brass ball of the sun was rising fast over a white-hot horizon. To the west, toward the Taklamakan Desert, all was still dark, and the summits of the distant dunes were edged with gold as the sun caught them.

In between was what Aurel Stein must have seen, with weary thanksgiving and relief. Rising between the dunes, their vertical spires contrasting dramatically with the desert realm of the horizontal, were trees—green trees, thousands of them. There was water somewhere nearby. This truly was an oasis, a place of refuge and settlement. I could see plenty of evidence of that as I clambered to a higher point: buildings, scores of them—the upswept eaves of a nest of pagodas, the minarets of a mosque or two, a cluster of hotels.