The Dark Forest Hypothesis stipulates the existance in the universe of a great many advanced civilizations, the only thing keeping them invisible and unseen being their own fear of being discovered by other hostile - and more advanced - polities. And so they stand, still and silent and unseen.
It is an interesting, if pessimistic, solution to the Fermi Paradox - if they really are out there, why can't we find them?
Well, it’s not entirely wrong, you see. Just... not quite right, either. Hostility is rare. On the other hand, curiosity is not. Nor are size differences – mostly extreme.
***
Earth - in its loud, screaming form, like a child throwing a tantrum in the radio spectrum - had been really quite visible for decades, by that point. They had been looking for aliens quite frantically, and in the late 2020's they would find them, in the most horrible form.
Tourists.
The first ones to consider a trip were Lilliputians (a flavorful translation, in truth) - minuscule aliens, really quite fearful of everything they had peeked of their neighbors. Silently, they watched, hopefully unseen. So you can imagine their excitement when they found minuscule, pathetic Earth.
It wasn’t long before an enterprising organizer started preparing for a travel to that wonderful, defenseless planet; no communication nor warning was sent to the destination, because that would have been careless in the extreme. Moreover, why warn them? It wasn’t like it would change anything.
The British Isles didn't survive their first visit: as the gate opened over Wales, stretching far into the sky, people scarcely had time to react before a small stream of girls, a couple dozens, started flowing excitedly out of it. White skin, wiggling purple tentacles instead of hair. 40km each.
There was no hope for salvation: within six hours, the gaggle of excited girls had razed every single settlement within a thousand kilometers of the portal. There had been no overt malice - no "DIE, BUGS", or the like - but that was meager consolation to the dozens of millions trampled into nothing. Monuments had been torn off and eaten, or used as jewelry; urban centers had been meticulously crushed under soft soles looking for a massage; ships had been toyed with, or sunk in the tsunamis caused by girls washing off human grime, or flattened into the seabed without a hint of recognition.
And while Britain bore the brunt of that short picnic, with London in particular having been undone to the last brick, steel bar, and living being by the excited steps of a few girls curious to know how it felt to crush a whole metropolis under their bare feet, grievous damage was widespread. The Netherlands couldn't have walled off the tsunamis following the girls' playful romp, but even if they could have, those dikes would have been shattered by the titanic, rolling bodies of two girls play-fighting on Holland, handfuls of civilized mud thrown at each other in childish reveling. Paris and Northern France had been used as a toilet, streams of urine cutting through the land in jets hundreds of meters wide; the Eiffel Tower, the Louvre, Notre Dame blasted apart before their shattered remains were spread in the yellow marsh that had been the City of Love and its hinterland.
And a frisky trio, looking for some privacy, had crossed the Atlantic, a puddle barely covering their ankles; the thought of a multi-million people orgy must have been incredibly invigorating, because they kept going and going and going, until they joined the departing group, sweaty and happy. They were the only survivors of the event, because their unwilling companions had disappeared, the coastline annihilated in a 100km radius around former NYC. The only remnants were scattered debris around their womanhood, and the Statue of Liberty, unnoticed, smeared on a clit like a coppery mole.
And then, without looking back, they left.
Chaos was absolute, of course. What had just happened, the death of two hundred million people in mere hours and ecological damage befuddling any imagination, was impossible to digest. Governments flailed for days trying to get something done, but in vain.
And they came back, barely a week later, spearheaded by the trio who had so enjoyed the land beyond the puddle, and that too resulted in damage untold: twenty of the girls, joined in joyful and writhing copulation, rolling through the entire East Coast of the US laughing and screaming in pleasure. Everything from Florida to the Maritimes ceased existing, ravenously consumed to fuel the girls’ lust or merely flattened into sweat-logged creaters by trillions of tons of flesh. Once more, nothing remained after they left, dozens of millions vaporized in hours. And yet, the worst was to come.
Because the Gulliverians (another fanciful translation) had been watching the situation unfold, and they had found it beyond amazing: not one, but two tiny alien species! The Lilliputians would in due time get their share of grief from those brief visits, but Earth wouldn't be there to care for it.
***
It happened during the third Lilliputian visit, a trip around the Mediterranean that had already seen the Pyramids kicked into the sea and the Holy Land made into beach towels: the largest one, thus far, forty giggling girls enjoying being the monsters, for once, and not the bugs fearing discovery.
Then, they appeared from an eerily silent crack in low Earth orbit, with a graceful landing which would have been gentle if not for their size; the first arrivals reasonably panicked as well, because they struggled to clear the pinky toes of the red-skinned, red-scaled, clawed aliens in front of them. But to humanity, the poor souls who had been powerless already in front of those minuscule bugs, the quintet was apocalyptic, their feet having glassed the entire Sahara and the Arab peninsula just through their arrival, the ISS crashing into the heel of one of the 8000km titans.
The Lilliputians beat a hasty retreat (too hasty, in fact, as it left behind evident traces of their destination and home-world - but that's another story), and the Gulliverians were left free to have their own fun.
And fun they did have, though they were the only ones to do so.
In the hours that followed, everything humanity had known was erased from existence. The leviathans proceeded to unmake, beyond the mere works of men, the very lands they had been living on: the concept of geography stopped having sense, as the landmasses themselves ceased to be under their bodies.
The entire Italian peninsula was torn off and inserted like an incredibly disappointing dildo, an end Japan also suffered and which caused the same disappointment; the girls had to finish with their fingers what countries had been unable to offer, their doomed cities rendered into juice-soaked dust.
Hungry maws fell on India, fangs many times taller than the highest mountains ripping away cities larger than the Gulliverians had ever seen, and at the same time so small to make that impossible; wiggling wet tongues scoured the land into vast, soggy depressions filled with saliva and debris.
But India proved to be too meager a meal: Indochina was not spared, though Kuala Lumpur and most of Malaysia received instead the dubious honor of being deleted by a careless nipple and then the rest of her breast. Indonesia followed, as the girl disappointed by Japan consoled herself with China.
All the while, half a dozen soles were falling, again and again and again, as three of the girls launched themselves in some frenzied dance. Like a terrible whirlwind, their feet started crushing all that stood in Western Europe, even the few ruins left by the Lilliputians vaporized wholesale. And the wave of red flesh kept moving east, deft clawed toes making sure to smear even those few patches that would have been merely pulped by the shockwaves; through and over Eastern Europe, over the Urals, through Central Asia and Siberia, the Himalayas scraped off by a lazy kick.
As they left Eurasia, its entire northern part had been reduced to a continuous expanse of trodden-over footprints carved in the outer mantle. There were no coastlines, no lakes, no mountains nor plains, no gulfs nor rivers; nothing but their infighting sole- and toeprints, over and over and over. They were then joined by the other two stragglers. One of them made a game out of poking every tiny Pacific island she could see, the Hawaiian Islands found worthy of all five toes on her right foot. The ocean itself failed to reach even her lowest toeclaw, even as it sunk twenty km in the seafloor.
The Americas, left to their own devices up to that moment, would again and for the last time be chosen as the theater for the aliens’ pleasure, although the scant devastation of the Lilliputians would again pale in front of the apocalypse wrought by those five continental bodies.
By the time they were done, a visible divot to the mantle was left where the Americas had been, wide gashes opened into the crust; an ungodly amount of ejecta leaving the planet, more yet falling into the surrounding devastation; their screams whipping through the atmosphere like nuclear shockwaves.
Their final act was relieving themselves, divided between the South Pole and the North Pole; the hundreds of millions of cubic km of scalding urine vaporized the icecaps almost instantly, a yellow wave adding up to a full third of all water on Earth.
One of them waved back as they disappeared into the crack.
As they vanished, giggles echoing like blasts long after they were gone, a few hundred thousand survivors in the southern hemisphere were left with no idea about what to do. The world was done for, the entire surface scoured by the shockwaves, and life almost extinct.
They wouldn't have to worry.
***
The lone Brobdinagian (notes above) never actually found Earth, but yet again, she never found anything. Another disappointment. Her soft blue toes itched for a second, but just a bit of wiggling fixed that. She went back home to confirm to her friend that no, Earth was not there, stop asking.
Mixed with the dirt between her toes, the molten splotch that had formerly been a beautiful blue marble a couple of relative millimeters in diameter started cooling off, though they would be washed off by a rapid shower before solidifying again on their own.