The light flew across the sky, something not seen for centuries on the Earth.
The world had overheated in the previous millennia, viruses and bacteria had spawned a plague and 90% of the population had died before a cure was found. The remaining humans were all children, the fate of their parents leaving them in a world of technology they could partly use but not maintain.
Then came the explosions, nuclear power plants went offline, nuclear bombs rotted in their silos. Crops and fruit failed. A few books had been left, some technical papers, but the schools were gone. Children grew to adulthood and learnt to hunt and gather like their ancestors. Technology was stored in caves, but without power could not be used.
Then came wars over food and clean water. People living near reservoirs were lucky, but those downstream were cut off as the pumping stations failed. Humans were close to extinction. As the fable said ‘how the mighty had fallen’.
But a few people learned electronics from taking old things apart then putting them back together. They tinkered and played, and a light rose in the sky which was artificial. Who knew what would happen next?