I was in a rut. It was the height of the Tiananmen Square upheaval, 23 years ago, and I'd been going there every single day, wandering round and interviewing the demonstrators. It was one of the great times in my life, but I needed a break.
So we went to the Great Wall. I wanted to film in a village where they'd never seen a foreigner before, and ask people there what they thought about the situation.
My local fixer was a poet, a man in his late 30s: gaunt, highly intelligent, a bit ragged round the cuffs. Clearly, poetry wasn't paying very well. He found a place to go, and we followed the line of the Wall until we reached the village Mr Tang had chosen. 'You're certain they've never seen foreigners here?' 'I am,' said Mr Tang gravely.
The village had scarcely changed since the Wall was rebuilt, 600 years before. We were invited into the headman's house and sat on his bed; it was a long brick wood-burning stove with a mattress on top. He gave us greasy tea and sat on a stool, grinning. His teeth were spectacularly bad.
As we filmed, I asked him if any foreigners had ever been here. 'Oh yes,' he said offhandedly, 'lots of them.' I turned angrily to Mr Tang: 'I specifically said...' 'Ask him when they came here,' Mr Tang suggested, serenely. It
was, the headman said, during the Mongol invasion of 1276. 'They came right through here. And now here you are.' Bloody foreigners, he seemed to be saying — will you never leave us alone?
Now, a quarter of a century later, China has changed utterly. Every house in the village I visited has a television set and a washing machine. The beds built over brick stoves will all have been ripped out. If the headman is still around, he may even have been to the dentist.
Now I was back. We were visiting a superb hotel, made up of small self-contained lodges built in ancient Chinese style, beside a river. On the hilltop above runs the Great Wall, looping off magnificently out of sight in the blueish haze. The hotel staff are Tibetan, and the food is unexpectedly spicy and hot.
The owner is even more unexpected: a tall, glamorous, silver-haired American called Laurence Brahm, who was an economics adviser to a recent Chinese leader, Zhu Rongji. ('Zhu is different from the others,' Lawrence said. Indeed, when the Communist Party Congress began, back in October, Mr Zhu was the only senior figure in the stiff ranks of dark-suited party bosses who had refused to dye his hair black.)
Ahead of us, Laurence clambered up the nearby bit of the Wall, where we were going to film. You could see three distinct levels of wall-building: the dark brown stone blocks of the Qin Dynasty, the period of ancient Greece. On top of that were large chunks of limestone, built with better craftsmanship, from the Han Dynasty, roughly the time of ancient Rome. And above, a watchtower in grey stone, the cement still gleaming white: its dominant ingredient was rice powder, apparently. This dates from the Ming Dynasty, roughly our later Middle Ages, Tudors and Stuarts. The Great Wall as we see it now is a Ming structure.
This particular section is dilapidated and hard to negotiate. It isn't one of those nice tidy parts where foreign celebrities go, and where tourists stride along with backpacks or take photos of one another. It's unvisited, unrestored, elegantly decaying, like the vast majority of the Wall. You feel as though you own it.
The Wall follows the Inner Mongolian border and succeeded for large parts of its history in keeping the Mongols out — not, though, in 1276. But you can't see it from the Moon, as the old wives' tale has it. How could you? No matter how long it may be (roughly 13,000 miles) it's only about 20 yards wide — far too narrow to be observable from a distance. Oh yes, and since I'm being irritable, please don't pronounce Beijing like the colour beige any more. The 'j' is hard, and the name rhymes with 'raging'. There: I feel better for getting that off my chest.
And I feel better for something else, too. Some years after Tiananmen, I came to Beijing and was fossicking around in a dusty antiquities store. 'I like this,' I said to the man who ran it, pointing to a clay figure on horseback. 'No,' he said, 'not real. Don't buy, please.' I don't think I've ever heard a dealer say something like that to me before.
'You don't remember me,' he added, as though it explained something. I didn't. 'You interviewed me in Tiananmen Square.' He dropped his voice as he said the words. It was true: I had. I checked it up later in the BBC video library. Now he was an antiquities dealer. Over the following years he taught me the tricks of the trade: how to spot the forgeries, where the genuine stuff came from, and how to bargain effectively.
In the end, sadly, I lost touch with him. His shop was bought up by someone else, who cleaned out the dust and went upmarket, and the new people didn't know what had happened to him. But when I came back from Laurence Brahm's wonderful hotel beside the Great Wall and wandered past the place where the shop had been, my latest fixer, a bright and charming young woman, got impatient with my lack of initiative. 'Of course we must find him,' she said, and starting questioning the nearby shopkeepers.
At that moment, by an extraordinary coincidence, the man himself turned up. We recognised each other, despite the passage of the years, and he threw his arms round me. It was a superb moment. But I noticed he still dropped his voice when he mentioned Tiananmen Square.
John Simpson is the BBC's world affairs editor and can be seen around the globe on BBC World News, available in 200 countries and territories worldwide, and on selected British Airways flights. Read more of John Simpson's travel tales.
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