The towers were immense and beautiful, rising powerfully from the earth and flung into the sky like a handful of silver arrows. They soared and shone — a vision of steel and glass and air. Pure creation, the perfect dream of the people who lived beneath them. They had gathered there, in awe and deference, as the towers started to grow. They stayed to watch and then they stayed to live. They began and ended each day by looking up.

Beneath the towers, great mines were sunk deep into the ground. Vast, plunging shafts disappeared into the earth, spawning countless tunnels and burrows and holes. They worked in these tunnels, hewing the rock that held the precious metal that built the magnificent towers.

They fed the towers, digging deeper to raise them higher. They urged them up, and the towers grew taller each day. People bent their necks further and further to see the top.

The bright metal caught the light and dazzled them. Every hour, a new angle, a new amazement. At the highest reaches, where it was cold, ice formed on the towers, which made them sparkle even more. Far below, it seemed the towers were made of diamonds. The people were amazed: their rocks had become steel, and the steel had become diamonds.

Each day, too, the mine became deeper and emptier. The shafts rooted further into the hollow earth as the miners hauled out their loads. With each bucket drawn from the earth, the towers were fed.

At last the mine was exhausted, and the towers could grow no more. The earth beneath it was hollow and the sky above was no closer.

“It will fall into the hole it came from,” said the stranger. “The ground is exhausted, it cannot possibly hold it up.”

No one noticed him, they just lifted their faces and smiled. The stranger moved on.

They crashed, of course. One afternoon, at a moment of particular beauty. The people were in breathless bliss, ignorant of the groaning surrender in the ground beneath them. There was nothing to say about the shuddering earth, the soughing of the towers. Nothing but blank and terrifying splendour as the precious metal came closer, faster, suddenly nearer to the ground.

The towers collapsed like a telescope and disappeared into the gaping earth with a ferocious roar and a pulverising storm of dust and glass and steel. The shafts and pits below the ground swallowed them whole; everything fell into place with a precise and devastating ease. The world ended as easily as closing the lid of a box.

Later, the stranger returned, but he did not mark where he was. There was just trackless desert. His horse’s feet struck sparks from the rocky ground, but the stranger did not notice. He did not see the light that glinted among the stones ahead of him. He was adrift in his thoughts, and cast the only shadow on the land. Nothing beside remained. Nothing beneath could move.