The Long Cosmos Read online

  Dedication

  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

  Dedication

  Foreword

  Chapter 1

  Chapter 2

  Chapter 3

  Chapter 4

  Chapter 5

  Chapter 6

  Chapter 7

  Chapter 8

  Chapter 9

  Chapter 10

  Chapter 11

  Chapter 12

  Chapter 13

  Chapter 14

  Chapter 15

  Chapter 16

  Chapter 17

  Chapter 18

  Chapter 19

  Chapter 20

  Chapter 21

  Chapter 22

  Chapter 23

  Chapter 24

  Chapter 25

  Chapter 26

  Chapter 27

  Chapter 28

  Chapter 29

  Chapter 30

  Chapter 31

  Chapter 32

  Chapter 33

  Chapter 34

  Chapter 35

  Chapter 36

  Chapter 37

  Chapter 38

  Chapter 39

  Chapter 40

  Chapter 41

  Chapter 42

  Chapter 43

  Chapter 44

  Chapter 45

  Chapter 46

  Chapter 47

  Chapter 48

  Chapter 49

  Chapter 50

  Chapter 51

  Chapter 52

  Chapter 53

  Chapter 54

  Chapter 55

  Chapter 56

  Chapter 57

  Chapter 58

  Chapter 59

  Chapter 60

  Chapter 61

  Chapter 62

  Chapter 63

  Chapter 64

  Chapter 65

  Chapter 66

  Acknowledgements

  About the Authors

  Books by Terry Pratchett and Stephen Baxter

  Credits

  Copyright

  About the Publisher

  Foreword

  THE LONG EARTH 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 ‘Long 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 ‘big 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.

  1

  JOIN US

  ON THE MOVE, ‘down’ was always the direction of Datum Earth. Down to the bustling worlds. Down to the millions of people. ‘Up’ 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. ‘What’s it all about, honey?’ he asked softly. ‘How 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 ‘Stepper 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 – 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 – 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 – the two women, polar opposites, who had defined his life – 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 – 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:

  ‘It’s impossible,’ said Stella Welch, staring at a tablet.

  Dev Bilaniuk sighed. ‘I 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 ‘Invitation’, the message the radio telescope called Cyclops had picked up, as Dev was.

  ‘For one thing,’ she said, ‘we haven’t even finished Cyclops yet.’

  ‘Sure. But the tests of the sub-arrays have proved successful so far. And we were just switching around various sample targets when this – this SETI thing – just showed up in the data feed and downloaded itself and—’

  ‘Also 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 radi
o messages in this particular sky. This is a Long Earth wide phenomenon. How the hell can that be?’

  Hesitantly Dev said, ‘There 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 call—’

  She seemed to dismiss that. ‘And then there’s the decryption.’ She looked again at the tablet screen, the two blunt words, in plain English: JOIN US.

  ‘There seems to be a lot of information buried under that basic pattern,’ Dev said now. ‘Maybe we’ll need the full Cyclops array to be up and running to extract all of that.’

  ‘But the point is,’ she said heavily, ‘that 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.’

  ‘And other languages too,’ Dev said. ‘Human 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.

  ‘How? ’ Stella snapped now. ‘How 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. ‘Professor 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. ‘Tell me what you think anyway. Any ideas?’

  He shrugged. ‘I guess that, unlike you, I’m used to sharing a world with beings smarter than I am. These – Sagittarians – 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.’

  She smiled. ‘We both know the answer to that.’

  He grinned back. ‘We’re gonna need a bigger telescope.’

  JOIN US

  And even further from Datum Earth:

  One day Joshua Valienté would call this elderly troll Sancho. But he already had a name, of sorts, in this troll band – not a name any human could recognize or pronounce, more like a complex summary of his identity, a motif in the trolls’ endless song.

  And now, feeding with the others on rich bison meat, as the light of an early spring day slowly faded, Sancho was disturbed. He dropped his chunk of rib, stood up and scanned the horizon. The others grunted, briefly distracted, but they soon returned to their meal. Sancho, though, stood still, listening, watching.

  It had been a good day for these trolls, here at the heart of a different North America. For some days they had been tracking a herd of animals that were like bison but not quite, with the trolls’ cooperative, communal eye on one particular elderly male who, limping heavily, had been trailing behind the migration. As the trolls had moved steadily towards the setting sun, invisibly paralleling the bison’s motion in worlds a few steps away, their scouts had continually flicked across to watch the prey, stepping back to report their observations in dance and gesture and hooting cries.

  At last the elderly bison had stumbled.

  For the bison himself it was the end of a slow-burning, lifelong story. One hind leg had never properly healed from a splintering break he had suffered as a mere calf; now that leg finally betrayed him.

  And the bison, downed, panting in the heat, was immediately surrounded by hunters, big heavy humanoids, their hair black as night, stone blades and sharpened sticks in their massive hands. They closed in, cutting and slashing, aiming for tendons and hamstrings, seeking to sever veins, trying to stab to the heart. Trolls were sublimely intelligent in their way, but not as toolmakers. They did use shaped stones and sharpened sticks, but they had no way of striking at a prey from a distance; they had no bows, not even throwing spears. And so their hunting was direct and close-up and gloriously physical – big muscular bodies thrown at the prey until it was worn down through the sheer application of strength.

  The bison was old and proud, and he bellowed as he tried to stand, to fight back. But he fell again under waves of assault from the hunters.

  It had been Sancho who had struck the final blow, smashing the bison’s skull with a single blow from a massive rock.

  The trolls had gathered over the fallen beast and sung their victory song, of joy at the prospect of a meal, of respect for the bison’s gift of life. Then they had fallen to the work of butchering the carcass, and the feasting began: the liver first, the kidneys, the heart. Soon the news of this kill would resonate in the trolls’ long call, shared by bands across thousands of worlds – and it would lodge for ever in the deep memories of certain older trolls, like Sancho.

  But now, as this happy day was ending, Sancho was distracted from the kill, the feasting. He had heard something. Or . . . not heard.

  What was it? His mind was not like a human’s, but it was roomy and full of dusty memory. He knew no human words. But if he had, he might have called what he heard, or sensed, the Invitation.

  Sancho looked around at the pack, males and females and cubs feeding contentedly. He had spent years with this band, seen the little ones born, the old fail and die. He knew them as well as he knew himself. They were his whole world. Yet now he saw them for what they were: a handful of animals lost in an empty, echoing landscape. Huddling, vulnerable in the dark.

  And, from beyond the horizon, something was coming.

  JOIN US

  And in a world only a few steps from the Datum, in a new stonebuilt chapel in the footprint of an ancient English parish called St John on the Water:

  Nelson Azikiwe was seventy-eight years old and officially retired. Indeed, he had come back to this place because his old parish on the Datum, although icebound on a world still suffering through a long volcano winter, was the place where, in his long and peripatetic life, he had felt most at home. Where else to retire?

  But to a man like Nelson retirement was only a label. He continued to work to the limits of his strength on his various projects, as much as he ever had. It was just that now he was entitled to call it play, not work.

  Of course it helped greatly that the growing technological infrastructure of this Low Earth provided the communications he needed to keep in touch with the wider world, and indeed worlds, without his needing to leave the comfort of his lounge. Thus he spent time each day communicating with the Quizmasters, an online group of ageing, grumpy paranoid obsessives – none of whom, as far as he knew, he had ever met in person – who were now scattered over the Low Earths and beyond, and yet across the decades had managed to remain in regular touch with each other, if necessary through the stepwise swapping of memory chips. It was an odd fact of the Long Earth that, more than half a century after Step Day, still nobody had figured out how to send a message across the stepwise worlds save by carrying it by hand.

  Just now the phenomenon that was becoming known as the Invitation was snagging the Quizmasters’ attention. The news of the receipt of an apparent SETI signal by a radio telescope at the Gap had been a nine-day wonder in the news media of the Low Earths, insular and inward-looking and obsessed with local politics and celebrities as they were. There had been a flurry of reports, a firestorm of speculation over mankind’s galactic future or its imminent cosmic doom, before it was all forgotten. But not by the Quizmasters.

  Some believed it must be what it most obviously looked like, some kind of SETI message from the sky: the fulfilment of the dreams of the decades-long Search for Extraterrestrial Intelligence, a message whispering into radio telescopes on any stepwise world where they had been established. Others believed it couldn’t be that precisely because
that was the most obvious explanation. Maybe this was a covert military experiment, or some kind of corporate viral infiltration, or the first moves in the long-anticipated Chinese invasion of a prostrate post-Yellowstone America.

  And it was as Nelson was sifting through another day’s communications on this burning topic that he received an invitation of his own.

  The screens of all his tablets and other devices suddenly blanked. Nelson sat back in his chair, startled, suspecting a power outage – not uncommon in a world that relied on the careful burning of wood for its electricity supplies. But then one screen after another lit up with a familiar face: a man’s face, calm, head shaven.

  Nelson felt a tingle of anticipation. ‘Hello, Lobsang. I thought you’d gone away again.’

  The face smiled back, and the multiple devices in Nelson’s room resounded to a voice like the beating of a gong in a Buddhist temple. ‘Good afternoon, Nelson. Yes, I have – gone away. Think of this presence merely as a kind of messaging service . . .’

  Nelson wondered how much of Lobsang he was talking to. Since Lobsang, when fully functioning, had seemed to run much of Datum Earth, for him vocal speech must have been about as efficient a method of communication as yodelling in Morse. Probably this avatar wasn’t much more than a sophisticated speech generator. And yet, Nelson reflected, he had taken the trouble to have this ‘messaging service’ smile at his old friend.

  Lobsang said now, ‘I have some news for you.’ The tablet before Nelson cleared again, and Lobsang’s face was replaced by that of a child, a sun-kissed boy aged maybe ten or eleven. ‘This is somebody I only just discovered myself. A remote probe called in, rather belatedly . . .’

  ‘Who is he?’

  ‘Nelson, he’s your grandson.’

  JOIN US

  And much further from the Datum, indeed more than two hundred million steps out:

  The USS Charles M. Duke wasn’t Admiral Maggie Kauffman’s boat. At sixty-eight she was much too old for operational command, and was in fact formally retired, not that that kept her from troubling her former superiors and nominal successors in the echelons of what remained of the US Navy. Yet this latest mission into the deep Long Earth was her idea, her inspiration – hell, the result of a twenty-five-year-long campaign on her part to resolve an item of unfinished business.