According to ancient legend, a giant had piled rocks on the bank of the river, creating a dark mountain. The mountain was a cairn, placed by the giant so that one day he could find his way back from the frozen North, to take revenge on the knights of old.
One morning the returning giant suddenly appeared over the mountain. He placed his hairy hand atop the rocky peak and sat down, cooling his feet in the trickle of river.
“What’s this?” he asked with a voice like thunder.
Across the river there had been a strange change. The castle had vanished. No knights in bright armor charged out to meet him.
Before him lay a postpostmodern city. Ant-size automated cars traversed a network of unpeopled streets, moving in straight lines from one point to another, then to another, then to another, then to another. The self-driving cars moved with perfect regularity between rows of identical, windowless edifices. The pod-like cars were also windowless, designed to deflect dangerous sunlight and conserve precious energy. They transported their minuscule cargoes with perfected efficiency.
The giant stared for a few minutes at the lifeless scene. None of it seemed real.
He soon lost interest.
As he stood up to return north, the clumsy giant accidentally knocked down a stone from the top of his useless cairn.
The catastrophic flood was beyond understanding.