The standard Alliance propaganda, when they talk about the exodus from Earth-that-Was, is that the planet "could no longer sustain our numbers, we were so many." It makes for a pretty story, sure enough, but that's about all it's good for. It's certainly not history.
The Council-that-Was, operating today under the aegis of Blue Sun, toes a different party line: the balance was permanently broken when a Slayer became Slayers, plural, and the demons grew ever stronger until humanity could no longer blind themselves to the monsters in the night. In fear, the richest and most powerful took ship and fled into the Black, and everyone left behind became prey to a planet overflowing with predators. Today, all that's left is a cinder of a world, baked clean in Hell's fires.
That second story sounds truer, dark with the grit of disappointing reality, but it's an even bigger lie. I know because my wife was there when it all began; she was the Slayer from whom one became many. Hellmouths fell like dominoes as her sisters spread around the globe, and the discovery of Chromosome 24 forty years after it started meant that each empowered girl had a chance at a normal lifespan despite their dangerous job. That's where I came in, and that's where the true story starts.
Anyone who knows how old the Earth truly is knows that humans aren't, by far, the first sentients to live there; many other species walked its hills and valleys before us, though most were travelers from other dimensions. Of course, those that know are few and far between these days-- there are more than seventy new Earths here to choose from, and none of them have the native magic every rock in the Sol system did. Still, there are those who remember and maintain the old legends. What even they don't know is that we aren't even the first evolution of this form, and that the original ancestors of humanity fled to our supposed homeworld in turn from Mars.
My sister could give you details about the lives of the people that lived in the ancient city at Olduvai, what they looked like, what kind of culture they had, and how no one had any idea they'd even existed until we found the Arks, but I never really bothered to memorize all the details. The single most important thing about them, from my point of view, is why they're not still there: they decided that being human-- or whatever they were-- wasn't good enough, and set out to make themselves better.
They succeeded beyond anything they could have imagined: they created a race of beings who lived longer, healed faster, moved quicker, and were far stronger and smarter than the rest of the species. But there's a pricetag on every gift, and that one was higher than most. Some of those who took the therapy evolved even futher, mutating into ravenous creatures that killed or infected every living being they encountered. Those who survived the chaos that followed, fled, burying their secrets for UAC to find.
Knowledge can't be unknown once it's discovered, not until every sentient being that carries it is dead. The scientists at Olduvai all perished at the hands of their first experiment, but some of their data survived, and from there the ending was inevitable. I was one of the lucky few who received the experimental therapy and retained my humanity; most of the others became monsters without reason, predators made up of hunger and rage. In the end, nothing anyone could do was enough to stop them.
And now it looks like old plots are being revisited: a new Olduvai was founded at Miranda ten years ago, thirty million people perfected unto death and another thirty thousand launched ravenous into the sky. And once again, it wasn't the government who revealed the truth, or any other authority; it was a young, powerful girl with a ragtag support crew. Scoobies of the twenty-sixth century, Browncoats and criminals all.
If we'd known five hundred years ago what use the Council would make of the discs we brought back from Olduvai, we would have snapped them then and there, the other Slayers be damned; if someone doesn't do what we didn't here and now, history is going to repeat itself again. We can't let that happen.
It's time for Buffy and I to come out of retirement... and it looks like Serenity may be the perfect place to start.