山 shān, the mountain: the holes worn into the rock by people carrying tea

Beijing. A stone called Neijing Tu, at the White Cloud Temple. Carved on it, a landscape. The stone is famous in Beijing. People come to stand in front of it and wonder what it means. We go back to the year 750 AD. Somewhere in the mountains west of Sichuan, a line of porters is moving. One of the porters is named Wei. This is the Tea Horse Road in Southwestern China. And down in the gorge, a line of porters follows a route worn into the rock by the ones before them. For a thousand years tea moved west over these mountains, and yaks, horses, mules and camels moved east in return.

The first hundred and forty miles of the tea road going west from the town of Ya'an crossed broken ground so dangerous and so steep that no pack animal could make the journey. Whatever made the journey, made it on a human back. So the road used the poorest people it could find. They were called bèifū, hired for their backs and their legs, because that was all the road required. Tea does not travel loose. It was pressed into bricks hard as wood, lashed to a frame, and the frame went onto a back, stacked higher than the head beneath it. Sixty to ninety kilos of it, smelling of wet earth and old smoke. After five days it's in the hair. A load that size cannot be lifted twice. Once it was up it stayed up, because nobody on a mountain path can lift ninety kilos back onto their own shoulders.

So it never came off, and it wore them. New porters bled at the hands, the shoulders, the lower back and the feet. The ones who lasted carried the heaviest loads. They had learned to be somewhere else while they walked. And they could not sit down. So they rested standing, on an iron-tipped staff cut like a cross, jammed under the frame to hold the weight a minute at a time. Eight miles was a good day, through landslide and gorge, over bridges with cloud where the ground should be. And they walked it as a line, so nobody could stop. One porter hesitating on a rope bridge held everyone behind them, and on a plank that wide there was no going around. Which left you your speed, and both speeds could kill you. Fast meant trusting a thin sandal on a board that might give. Slow meant giving the wind time to take you off the mountain.

Wei had given up counting the weight on the first morning, because counting the weight did nothing when the weight would not change. What Wei counted instead was steps — every morning a number was picked at random, and when the counting reached that number it started again at one, because the mind needed something to hold onto. Wei had given up looking at the distance on the third day. What was left was the mountain, and the line of backs in front. Ten at the last halt. A porter who fell behind above Ya'an did not catch up.

Lao Song had a little ceramic vial, which was a surprise, because he did not look like a man who could afford one. The group did not say the word for wolf on this road. The word they used instead was mountain soldier. They did not say the word for tiger. Instead they said high eagle. To survive, Wei knew they had to keep their wits about them.

Wei looked at the ground three steps ahead, and thought about the fire. And about Kangding, and the wage waiting there. And about the fact that the wage only existed if Wei arrived to collect it. And about whether this would be the last trip. Whatever was in the vial had worn off by dark. Ten at the last halt. Counted the group again. Nine. Nobody said either word.

Wei slept in a sack of woven palm fibre. A scribe at Anyang cut the same three into bone, two thousand years before this night. The mountain is ideal for carving with a knife. Wei drew the mountain as it was seen, without a second thought. Drifting further into the mountain, Wei's mind wanders. Two mountains are blocking the foolish old man's door, Every errand means the long way around. They sit exactly where the road ought to be.

So he calls his family together and tells them they are going to remove the mountains. They pick up baskets and begin to dig. A wise old man watches the family dig for a while and then laughs. The wise old man says: look at yourself. You are ninety years old, and you could dig for the rest of your life and fail to level a hilltop. And those are mountains. When I die, the foolish old man said, my sons will keep digging. When they die, their sons. And their sons after them. Generation without end. And the mountains do not grow.

The gods hear this and take fright. A family that cannot be outwaited. And they move the mountains themselves, and the door opens onto level ground. Nobody moved the mountains for the porters. Wei had never met the foolish old man, and knew how he spoke. The two old men argue all night. Neither of them wins.

The mountain sits in the eye as Wei wakes. Wei did not sleep again. Her head, a mountain at the centre of the world. Her spine, a river flowing through her. Under her ribs, terraces. And on the terraces, people working.

She looked inside and discovered her mountain. Take the Chinese character for person and set it beside the character for mountain and the two together make a third character... Immortal. A person who goes into the mountains... and does not come back the same way. She stood and faced the road. It's hers to carry.

At Kangding she could stop. She had been carrying two the whole way. Still holding the mountain after three thousand years. You can say it now. That's the mountain. Next time.

The tree. The one they drew with the roots still on. And thank you very much for being here.