There's no one left to tell us what the world was like before Nemesis.
A handful of disreputable astronomers had long claimed that another planet might be hiding on the far side of the Sun, opposite the Earth. They'd guessed its existence from the changing paths of comets and the drifting orbits of other bodies in the solar system. But no one listened.
When it finally appeared, emerging from behind the black disc of the sun during an eclipse, just a mote in the brilliant corona, the world was stunned. Nemesis, they called it, but the believers said it was Wormwood, the Falling Star, and that its appearance signalled the ending of the world.
They were mostly right.
Shock turned to horror when observatories all over the planet soon after warned that Nemesis, once Earth's solar antipode, was drawing nearer, inexplicably slowing in its annual course. Despite the news, there were some who said it was all a lie, a conspiracy, that Nemesis wasn't even really there. It remained invisible to the naked eye, even at night, but astronomers said that was only because the surface of Nemesis was strangely dark, and reflected very little sunlight.
The intruder couldn't be ignored forever. It made its presence known in the night sky by its great and quickly growing silhouette. Eventually, it blotted out even the stars, and took a bite from the Moon.
Finally, one horrible day, the sun rose to reveal an unreal vision of terror and dread: an alien world near enough to consume the better part of the sky, with most of it still hidden below the horizon. With Nemesis so close at hand, a few of its surface features could finally be discerned. Here and there the ragged, gray shroud of its atmosphere glowed red, lit by what could only have been massive infernos below. Through wisps of cloud, mysterious, irregular clusters of smoldering, red nodes shone out, like unblinking eyes. Were they volcanic formations? Or Enemy cities? Thin, burning lines like Martian canali joined them in places.
The now-irregular binary orbit of the Earth and Nemesis resulted in frequent solar eclipses so great that it was as if the Sun itself had been snuffed. Nemesis would rise in the East, run high in the sky and plunge into the West in just a few hours. Or it would spin directly overhead for days, or slide across the horizon like a dark ship far out at sea. The effect was cripplingly vertiginous. The two worlds lurched on through space, locked in embrace.
Inevitably, the passage of day and night was affected, alternately slowed and quickened, as gravitational fields meshed, merged, and warped. Their diurnal rhythm broken, man and beast fell ill, and crops died in the field. Calendars and clocks failed. Chaos and madness followed, erupting in terrible plagues of violence. Cities burned. Nations fell. Civilization collapsed. Soon, even the tides were unfamiliar. The oceans strained against immemorial precedent as Nemesis loomed larger and larger in the sky, both day and night.
But when the end finally came, the world wasn't shattered or consumed in flame; it was drowned, and not by rain. At the moment of perinemion, Earth's crust cracked, and the waters of a great, dark ocean, long hidden below, spilled forth in a global deluge. What little was left of man and all he'd ever built was lost beneath the black waves.
In time, Nemesis spun off into space and disappeared. The waters receded.
The world had ended.
