My name is York. I’m fourteen years old – leastways, that’s by the Half-Lifes’ reckoning. Years don’t mean much in the Biosphere – nor months or days for that matter. There are no days or nights here the way there were on Earth.

I’ve seen pictures of Earth; the Earth we left behind a thousand years ago. The Half-Lifes have shown me. Trees, mountains, rivers; sunsets over deserts, moonrise over the oceans . . . There’s none of that here in the Biosphere, only light from the hull lamps illuminating the twists and tangles of the tube-forest that surrounds the Inpost.

The Inpost is home. My home. It’s the only home I’ve ever known – or am ever likely to know. A run-down mash-up of tech-sheds and mech-galleys hidden deep beneath the tangle and scuzz of the tube-forest. OK, it can smell of sweat and gunk-grease, and the holosimulations aren’t up to much.