The sun hung heavily on the western horizon, as if weary of the world that it had dutifully tended for countless millennia. It seemed an unimaginably long time since that chunk of rock - no more than a grain of sand in the relative grandness of the universe - had swung into orbit around the star. It seemed an unimaginably long time ago that the atmosphere of the infant planet had developed enough to allow the first lifeforms to appear. It seemed that an unimaginably long time had passed since those single-cell organisms had started to mutate - evolving and multiplying, clothing the world in a great variety of flora and fauna and bringing it to life. For an unimaginably long time the planet prospered, and grew, and was at peace.
Then the humans came - the humans with their spaceships, the humans with their grand technology, the humans with their great machines that rent the land apart in their search for coal, oil and other valuble natural resources. They tore up trees, dammed up rivers, turned valleys and forests into towns and great, sprawling cities which belched noxious fumes into the clear air of a planet that was, in the infinite life of the universe, still relatively young.
In just a few hundred years it became apparent that the damage was nearing a point where it would soon be beyond all hope of repair. As if angry at the pollution that had violated it, the world struck out repeatedly with devistating natural disasters sparked by chaotic climate change. It seemed that the land itself seethed in its ire, as if striving to topple those human built cities and factories that had so blighted it. Tsunamis tore at the coast, volcanoes spewed violently, great earthquakes sundered the land, leaving raw, gaping valleys and carving new mountains as physical wounds, as if in evidence of the violence committed against the infant world.
Humans had seen many planets die the same way - including their own native Earth - and decided that, this time, they would do something before it became too late. Many hotly debated meetings were held around the globe, ideas were offered up and cast aside in their turn.Society was just about to fall apart completely when, eventually, the world leaders came to a decision.
They abandoned their own cities, dismantled the dams, removed their electric pylons and cables. They shut down their factories and power stations, decommissioned their airways, trains and vehicles until, finally, the very last electrical light blinked out for the very last time.
The people of the world turned to a much simpler way of life; working closely with nature, growing their own crops, building their homes out of natural materials, adopting a lifestyle once enjoyed by their early ancestors and giving their surrogate world a chance to recover.
And their machines - their great, human-form machines capable of all the dexterity and intelligence of a human being, the great machines that had warned, time and again, of the effect humanity's greed would have on a world that was not their own, the great machines that had tried, for many years, to prevent the many disasters that had occured as a direct result of Man's negligence - were simply left to rot.
They remained where they were abandoned, their power drained away, their great mechanical minds shut down - no more than great hunks of metal that would soon become covered in the dust and dirt and grass of time. There they waited, patiently, for the time when they would be reactivated - for the time when they would once again be needed.
For they knew, as the humans themselves did deep in their hearts, that there would come a time in the distant future when their descendents would rediscover technology ... and then all the wisdom of the giant mechanical beings from another world would be needed to stop this planet suffering the fate that had so nearly befallen in when humans first set foot on its surface.
Ironically, without the technology the humans had abandoned to save their new world, the planet would be doomed.