This was originally written for /r/HFY, as the beginning of my quest to find a hypothetical scenario so absurd that it doesn’t have an apropos GK Chesterton quote.

His Hair Grows Green as Ours Grows Grey

A mountainous and mystic brute
No reign can curb, no arrow shoot…

I don’t think even the humans themselves knew it. They had seen the odd trends and patterns repeat themselves over thousands of years, but having no basis for comparison they did not realize how odd it was. The steam engine and mechanical computation were invented and then discarded for over a thousand years. Calculus was invented by two men at nearly the same time, as was the Möbius strip, the VX module, the carbon nanotube, and electromagnetic induction. Humanity suddenly lurched into space at the moon and just as suddenly retreated back to the comfort of low orbit. They should have realized that these were not disconnected events.

We should have realized that these were not disconnected events.

…But though in pygmy wanderings dull,
I scour the forests of his skull,
I never find the face, eyes, teeth
Lowering or laughing underneath…

The initial attack was trivial. Many humans did not even try to fight, and those that did seemed to spend as much time fighting each other as fighting the invasion of their world. They had strong weapons, but ours were stronger. They had ferocity, but our race was bred for nothing but war. They knew the land, but we knew the sky. We wiped out half of their population within the first week and were well on our way to destroying yet another potentially dangerous species. I recorded everything, of course, and absorbed the information from hundreds of thousands of their books and videos taken from remnants of their cities. I saw, and I heard, but I did not understand.

The strange phenomena that had characterized much of their entire history began to happen a week after we arrived. Ten humans in six countries independently discovered faster-than-light travel on the same day. One human discovered how a directed electromagnetic pulse at the right focus and intensity could cause our shields to momentarily fluctuate - and another, an hour later, invented a remote resonance amplifier to magnify the effects of shield fluctuation, in a lab that could have had no contact with the outside world. The nations around the planet were by and large no more cooperative with each other than before - but even with communication lines down, those humans who were fighting seemed to have a preternatural coordination. The battles ground to a standstill, and after a month ships seemingly built out of scrap metal and duct tape were engaging ours on equal terms. That is when I realized what was really happening.

We were not just bombing a planet. We were fighting a world. We had not declared war with humans. We had declared a duel against Humanity. Each individual human being was part of the unconscious immune response of a being we did not imagine possible, and the same collective force responsible for so much of their technological innovation and their endless and seemingly arbitrary conflicts was now focused entirely on us. An entity on that scale was slow to act, but once awake had capabilities we could not have anticipated.

…I met my foe in an empty dell.
His face in the sun was a naked hell.
I thought, ‘One silent, bloody blow.
No priest would curse. No crowd would know’…

It was no more than three months after the saturation bombing had begun that the last dozen of our ships fled the skies of Earth just ahead of the wake of an ingenious weapon that causes cataclysmic chain reactions in hyperdrive engines. To our knowledge, we were not followed - but less than a day after the end of hostilities, we detected hyperspatial emanations coming from their planet and moving towards their closest neighboring star system.

And that is why I am here. It is possible that, with the lack of external stimuli, the humans will stop expanding before they reach our outer colonies and resume killing each other. The giant we have awoken may yet go back to sleep. But we should not send our fleets, and we should not send our spies. It is a good idea to eliminate any species that could one day pose a threat to us, of course - but it is a very bad idea to attract the ire of a god.

…And then a daisy, half concealed,
Spoke for the fame of that poor field.
And in the flower and suddenly,
Earth opened its one eye on me.

– GK Chesterton, “Cyclopean”