And it was precisely because she was so hard to find that places she was known to call at – like Four Waters City, even though her visits were not frequent and certainly not regular – were so useful for getting in touch with Sally if you really, really needed to.

That was why the sheriff herself emerged from her office in the dawn chill, glanced down without much interest at the blubbing hunter, and called Sally over. Once back in her office she rummaged in a drawer.

Sally stayed outside the door. There were powerful aromas emanating from the office, a concentrated version of the colony’s general atmosphere, which she was reluctant to breathe in too deeply. This particular community had always been a culture suffused with exotic pharmacology.

At length the sheriff handed Sally an envelope.

The envelope was handwritten. Evidently it had been sitting in that drawer, in the office, for more than a year. The letter within was handwritten too, very badly, but Sally had no trouble recognizing the hand, even if she had some difficulty actually deciphering the note. She read it silently, lips framing the words.

Then she murmured, ‘You want me to go where? The Gap? . . . Well. After all these years. Hello, Dad.’

Friends of Lobsang’s like Joshua Valienté. Camping on a hillside on a world more than two million steps West of the Datum. Escaping the ongoing five-years-on disaster zone that was the Datum and the Low Earths, fleeing into the security of one of his long sabbaticals. Utterly alone, missing his family, yet unwilling to return to his unhappy home.

Joshua Valienté, who, having celebrated New Year’s Day of 2045 with nothing stronger than a little of his precious stash of coffee, woke up with a headache. He yelled into an empty sky: ‘What now?’

2

WITH HER FINAL STEP, Sally emerged a cautious half-mile or so from the fence surrounding the GapSpace facility. Inside the fence was what looked like a heavy engineering plant, blocks, domes and towers of concrete, brick and iron, some of them wreathed with plumes of smoke, or vapour from the boil-off of cryogenic fluids.

Willis Linsay, her father, had specified a particular day for her to show up here. Well, however this latest interaction with her father turned out, here she was as requested on this January day, back in this supremely strange corner of a version of north-west England more than two million steps from the Datum. On the face of it, it was a bland British winter’s day, dull, cold.

And yet infinity was a step away.

The moon was up, but it wasn’t the moon she was used to. The asteroid the GapSpace nerds called Bellos had spattered this moon liberally with extra craters that had almost obliterated the Mare Imbrium, and Copernicus was outdone by a massive new impact that had produced rays that stretched across half the disc. Bellos had come wandering out of many stepwise skies, its trajectory a matter of cosmic chance, coming close to the local Earth, or not. Bellos had completely missed uncounted billions of Earths altogether. A few dozen, like this one, had been unlucky enough to be close enough to its path to suffer multiple impacts from stray fragments. And one Earth had been hit hard enough to be smashed completely.

Things like that must be going on all the time across the Long Earth. Who was it that said that in an infinite universe anything that could happen would have somewhere to happen in? Well, that meant that on an infinite planet . . . Everything that can happen must happen somewhere.

And Sally Linsay had found this huge wound, with Joshua Valienté and Lobsang, found this Gap in the chain of worlds. Their twain had fallen into space, into vacuum, into unfiltered sunlight that hit like a knife . . . And then they had stepped back, and survived.

The air here was cold, but Sally sucked at it until the oxygen made her drunk. She had lived through that fall into the Gap once. And now, was she really planning to go back?

Well, she had to. For one thing her father had challenged her. For another, people were working in there now. In the Gap, in space. And this was their base, one step short of the Gap itself.

The sea breeze was the same as she remembered, from her last visit with Monica Jansson five years ago – back in a different age, the age before Yellowstone. The big sky, the call of birds, were unchanged. Otherwise she barely recognized the place. Even the fence before her had developed from a flimsy barrier into a regular Berlin Wall, all concrete and watchtowers. No doubt the interior of the facility itself was riddled with intensive anti-stepper security.

The purpose of all this industry was evident. She could already see the profile of one rocket, elegant, classic and unmistakable. This really was a space launch facility. But it was not like Cape Canaveral, in the finer detail. There were no towering gantries, and that single rocket she spied was short, stubby, nothing like the great bulks of a shuttle or a Saturn V – surely inadequate for the task of climbing up out of Earth’s deep gravity. But it didn’t need to beat Earth’s gravity, that was the point; that rocket would not be launched into the sky but stepwise, into the emptiness of the universe next door.

Overall, instead of being endearingly backyard-rocketship amateurish as it had been, the facility and its approaches now looked like one big engineers’ playground. The Gap had become big business these last few years, she knew, as governments, universities and corporations back on the Datum had gradually woken up to the potential of the place. Now hoardings shouted the names of every major technical outfit Sally could think of, from Lockheed to IBM via the Long Earth Trading Company – and including the Black Corporation, of course. This had become probably one of the most crowded stepwise locations beyond Valhalla, the greatest city of the High Meggers.

Which was one reason she hadn’t come near the place for years. And why it was hard to take a single pace forward, like she had a phobia. She reflected that Joshua Valienté would do better in this situation. Good old Joshua now seemed quite at home in moderately cramped social situations like this, while she was ever more a loner and a hardened misanthrope.

But it was her father who had summoned her here, and nothing could change him, for better or worse. Willis Linsay, dear old Dad: creator of the Stepping box, a gadget probably stolen out of the box from under Pandora’s nose and released into an unsuspecting world. That was Dad all over, tinker, tinker. If you couldn’t find him, just head towards the explosions and the wail of ambulances . . .

And as she stood there, reluctant, conflicted, uncertain, here he came, walking boldly out of the compound to meet her. How had he known she was here? Oh, of course he would know.

He was taller than she was – she had always had more of her mother’s colouring and body shape – and thinner than ever, like a man built of nothing but sinews and bone. After her mother had died he’d seemed to live on nothing but brandy, potatoes and sugar, for years.

He slowed as he approached her. They stood there, wary, eyeing each other.

‘So you came.’

‘What do you want, Dad?’

He grinned, a slightly deranged expression she remembered too well. ‘Same old Sally. Down to business, eh?’

‘Is there any point me asking what you’ve been doing – hell, since you turned the world upside down on Step Day?’

‘Pursuing projects,’ he murmured. ‘You know me. You either wouldn’t understand or you wouldn’t want to know. Suffice to say it’s all for the common good.’

‘In your opinion.’

‘In my opinion.’

‘And is there some new project that you brought me here for?’

‘Here?’ He glanced around at the GapSpace installation. ‘Here is only a waystation, en route to our ultimate destination.’