Authors: Terry Pratchett
The Long Cosmos
For Jacks Thomas and Malcolm Edwards, for their prodigious dinner parties at one of which the Long Earth series was reborn
T.P.
Seconded. And to Sandra, as always
S.B.
Contents
Books by Terry Pratchett and Stephen Baxter
T
HE
L
ONG
E
ARTH
project was born in the course of a dinner party conversation in early 2010, when Terry Pratchett mentioned to me a science-fiction storyline he'd set aside long ago. Before that party was over, we'd decided to develop the idea as a collaboration. Initially we planned two books, but by December 2011, when we had completed our draft of Volume 1 (
The Long Earth
), that first book had split into two, we couldn't resist exploring a âLong Mars' in Volume 3, and we were planning how to reach a grand cosmic climax for the whole series . . . So at that point we were able to present our heroically patient publishers with plans for a five-book series.
The books have been published annually, but we worked faster than that; time was not on our side, and Terry had other projects he wanted to pursue. Volumes 1 and 2 of the series were published in 2012 and 2013 respectively. But by August 2013 we had presented our publishers with drafts of the final three volumes of the series, including the present book. We did continue to work on the books subsequently. The last time I saw Terry was in the autumn of 2014, when we worked on, among other things, the âbig trees' passages of
The Long Cosmos
(chapter 39 onwards). It has been my duty to see this book through its editorial and publishing stages.
S.B.
O
N THE MOVE
, âdown' was always the direction of Datum Earth. Down to the bustling worlds. Down to the millions of people. âUp' was the direction of the silent worlds and the clean air of the High Meggers.
Five steps West of Datum Madison, Wisconsin, in a small cemetery plot outside a children's home, Joshua Valienté stood over his wife's marker stone. Down almost as far as it was possible for him to be down. It was a bitterly cold March day.
Helen Green Valienté Doak.
âWhat's it all about, honey?' he asked softly. âHow did we come to this?'
He'd brought no flowers. He didn't need to, so well did the children tend the little plot, presumably under the kindly supervision of Sister John, the old friend of Joshua's who now ran the place. It had been Sister John's idea to set up this marker, in fact, as a consolation for Joshua when he visited; Helen had insisted on being buried in the Datum, at a much less accessible site.
The stone was marked with the date of Helen's death, in 2067. Three years on, Joshua supposed he was still trying to come to terms with the brutal reality.
He was a man who had always sought to be alone, for big chunks of his life at least. Even his experiences on Step Day had come about because of that drive for solitude. It was now more than half a century since an irresponsible genius called Willis Linsay had posted the specifications of a simple home-workshop gadget called a âStepper box' online. And when you built it, strapped it on your belt, and turned the switch on the top, you found yourself
stepping
, a transition out of the old world, which everybody now called Datum Earth, and into another: a world silent and choked by forest, if you stepped over from a location like Madison, Wisconsin, as thirteen-year-old Joshua had. Turn the switch the other way and you went back to where you started â or if you were bold enough, as Joshua had been, you could take a step further away, on into one world after another . . . Suddenly the Long Earth was open for business. A chain of parallel worlds, similar but not identical â and all save the original Earth, Datum Earth, empty of humanity.
For a loner kid like Joshua Valienté, a perfect refuge. But wherever you fled to, you had to come back in the end. Now, sixty-seven years old, his wife dead, Sally Linsay long lost â the two women, polar opposites, who had defined his life â with even his only son more or less estranged, Joshua had no choice but to be alone, it seemed.
Joshua had a sudden, sharp headache, like a shock through the temples.
And, standing there, he thought he
heard
something. Perhaps like the subsonic rumble of a deep quake, sound waves so huge and energy-dense they were felt rather than heard.
Joshua tried to focus on the here and now â this plot, his wife's name on the stone, the slab-like buildings of this Low Earth, all timber walls and solar panels. But the distant sound nagged.
Something calling. Echoing in the High Meggers.
JOIN US
And, much further from the Datum, in an empty star-littered sky where an Earth should have been:
âIt's impossible,' said Stella Welch, staring at a tablet.
Dev Bilaniuk sighed. âI know.' Stella was in her sixties, more than thirty years older than Dev. Not only that, Stella was Next: so smart that when she really took off on some line of speculation or analysis, Dev, who with a doctorate from Valhalla U was no dummy himself, could barely see her dust on the horizon. Granted she didn't look all that smart now, from Dev's perspective, dangling upside down in the cavernous volume of this chamber deep within the Brick Moon, with her mass of zero-gravity grey hair stuck out at all angles.
And she did seem to be as baffled by the âInvitation', the message the radio telescope called Cyclops had picked up, as Dev was.
âFor one thing,' she said, âwe haven't even
finished
Cyclops yet.'
âSure. But the tests of the sub-arrays have proved successful so far. And we were just switching around various sample targets when this â this SETI thing â just showed up in the data feed and downloaded itself andâ'
âAlso we've had reports that other 'scopes, mostly in the Low Earths and the Datum, have been picking this up too. That is, on other worlds stepwise. This isn't just some beacon firing off radio messages in this particular sky. This is a
Long Earth wide
phenomenon. How the hell can
that
be?'
Hesitantly Dev said, âThere have been some odd reports on the outernet too. Funny stuff out in the Long Earth. Nothing to do with radio astronomy. Strange stuff in the trolls' long callâ'
She seemed to dismiss that. âAnd then there's the decryption.' She looked again at the tablet screen, the two blunt words, in plain English: JOIN US.
âThere seems to be a lot of information buried under that basic pattern,' Dev said now. âMaybe we'll need the full Cyclops array to be up and running to extract all of that.'
âBut the point is,' she said heavily, âthat what we have received came with its own decryption algorithm encoded into it, like some kind of computer virus. An algorithm capable of translating its own meaning into
English
.'
âAnd other languages too,' Dev said. âHuman languages, I mean. We tested that. We downloaded the thing into a tablet owned by a native Chinese speaker among the crew here . . .'
Dev had got a corporate reprimand for that. But the tense relations between China and the western nations down on the Datum meant nothing here, two million worlds away.
â
How?
' Stella snapped now. âHow the hell can it
speak
to us? Presumably without any prior knowledge of humanity and our languages? We think this was sent by some civilization far off in the direction of Sagittarius, many light years away, maybe even somewhere close to the centre of the Galaxy. Our radio leakage can't have got that far, even from the Datum.'
Dev, bombarded, lost his patience. âProfessor Welch. You're senior to me in the field by decades. You wrote the texts I studied from. Also you're a Next. Why are you asking me?'
She eyed him, and he saw a glint of humour under her irritated impatience. âTell me what you think anyway. Any ideas?'
He shrugged. âI guess that, unlike
you
, I'm used to sharing a world with beings smarter than I am. These â Sagittarians â are smarter than that again. Smarter than
you
. They wanted to talk to us, and they knew how. The important thing, Professor, is to figure out what to do next.'