Nobody ever really agreed on how the war started. It was over in less than a week, and what it left behind lasted for generations.

For days afterwards, something kept falling from the sky. People thought it was snow. I suppose they wanted it to be.

It was fallout. The smoke from the fires had gone so high that the sun hardly got through, and the harvests failed, year after year.

Then the power started failing. Hospitals, water treatment, transport — everything we depended on. Eventually, people began abandoning the cities.

By then, if you wanted any hope at all, you had to look a very long way off.

It had water, air and signs of life, and some people wondered whether ours could take hold there too, given a few centuries.

Nobody imagined we'd need the answer so soon.

Genesis carried no crew. It carried seeds and frozen plant embryos, soil bacteria and fungi, and algae and plankton for the sea and the rivers.

There were libraries of genetic records for anything too complicated to send alive. And the machines needed to bring those samples to the surface, cultivate them and look after them.

Decades later, Genesis reached a world that had been alive for a very long time.

Most of those early trials failed. Some things died within days, and some only lived because the machines kept nursing them.

It took years of preparation before the machines finally planted a tree outside their controlled environment.

That one lived.

None of it replaced the native life. Earth's plants and microbes grew in among it, and not always the way anyone expected.

What's down there now isn't a second Earth, and I'm not sure it should be. It's part ours and part its own, and we understand far less of it than we'd like.

There was no time to design a colony ship, so they took a freighter that was still being built in orbit and taught her to be one.

They gave her a shield, landers and robots, workshops and stores, a recovery suite for the people who'd wake at the other end, and an intelligence capable of keeping everything running while they slept.

She was never designed for this, and the people who finished her knew it. But she was one of humanity's last hopes of survival, so they did it anyway, and they did it well.

The crossing took eighty-four years, and nobody was awake for it except the ship.

Late in the crossing we ran into debris nobody had charted, and she came out of it worse than she looks. But we're here, and as far as I can tell, her cargo came through intact.

Genesis has had nearly another century to work since its last report reached Earth. By now the forests should have spread, and there ought to be more life in the sea. The air might even be safe to breathe. I'd rather we tested that before anyone takes their helmet off, though.

Right. Time to wake someone up.