Twelve hundred years ago along the Silk Road, the Diamond Sutra, the oldest printed volume in the world, was buried deep within a remote cavern in Dunhuang, China. Simon Winchester explores the mysterious Caves of the Thousand Buddhas, where he unravels the riddle of how Buddhism was brought to the Middle Kingdom and how the sutra ended up in London's British Library.

It is commonly believed by most Westerners that the world's earliest printed book was produced either by Herr Gutenberg in Mainz (a Bible) or by Mr. Caxton in London (a French novel), and that the revolutionary invention of the movable type with which it was printed came about in the fourteenth or fifteenth century. Westerners often get such things badly wrong. In fact, the world's oldest printed volume is a sixteen-foot-long scroll of religious instruction called the Diamond Sutra. It dates from the ninth century, and was created using woodblock printing. A Chinese copy of early Buddhist Sanskrit text, the scroll now lives in a perpetually guarded case in London's British Library. And it was found 101 years ago in a remote Silk Road cave in a northwestern Chinese desert between Mongolia and Tibet.

Its discoverer—and the discoverer of a great deal else besides—was a diminutive and heroic Hungarian-born British knight named Aurel Stein, a man of extraordinary austerity, courage, and self-reliance who preferred the company of dogs (he had seven in his lifetime, all of whom he named Dash) to that of mankind. He arrived at the immense and then little-known cave system of Dunhuang after a journey involving weeks of privation, by way of an endless caravan of camels and donkeys. The importance of his finds, and the cultural and historical legacy of what is now known as the Caves of a Thousand Buddhas, extend far beyond imagination, and few who manage to visit them today fail to undergo a mystical transformation, as Sir Aurel most certainly did.

Getting there can be tricky, at least if you come by land. I almost didn't arrive—and the fact that I eventually did get to see the very cave from which the Diamond Sutra came has much to do with the present-day magic of Chinese technology. It also has much to do with the Chinese government's flair for the planning (if I may be allowed so prosaic a thought while speaking of such a treasure house of antiquity) of the present-day infrastructure.

I had already been driving westward up the Silk Road for two full days. I was in a sturdy Shanghai-built Volkswagen Passat—newish, with good all-weather tires. It was soon after I passed the Ming dynasty fort at Jiayuguan, built as a customs post and a gate at the western end of the Great Wall, that disaster struck. Suddenly there was a bang! from somewhere beneath the car, and all the warning lights on the dash started to flash red.

I leaped out, fearing the worst. It was getting dark, and cold, and there was a gritty north wind. A flashlight confirmed my fears: I had hit a rock in the road, and a pool of thick black engine oil was forming on the sand. A warm stream of it was pouring from a deep crack in the cast-iron engine base. Within a few moments the car was undrivable—the pistons and crankshaft unlubricated, ready to seize in a screeching instant. My interpreter and I sat in the dark, helpless. The nearest village, a small place called Anxi, was forty miles ahead. Dunhuang was a further one hundred miles, at least. There was no traffic. It was nighttime. And it was now very cold. We were, to put it as bluntly as I can write here, well and truly buggered.