But, apart from the very occasional pinprick of a campfire, or the even rarer lights of a small township, there was no sign of mankind.

Joshua remarked, ‘Nobody at home. And yet you still meet people, especially back on the Datum, who will tell you we conquered the Long Earth.’

Rod shrugged. ‘So what? Why do you need to conquer, or not conquer, anything? Why not just accept things the way they are? Because even if they do change, you can always just step away …’

And Joshua saw that that really was how Rod thought about the world, or worlds: as a kind of endless now, an endless here, a place where location and time didn’t matter – and endlessly generous, a place you didn’t need to work at, didn’t need to build on, or fix. A place of endless escape. Joshua felt a sudden, intense jumble of emotions. Born in the Long Earth, Rod was of a generation that was forever divided from Joshua’s by the great chasm of Step Day, and never could their world views be reconciled.

He couldn’t help it. He reached over and grabbed Rod’s shoulder, squeezing it hard. But Rod failed to respond.

It was a relief for both of them, Joshua suspected, when noon arrived and the plane banked over an uninhabited footprint of the Madisonian lakes, precisely three thousand steps West of the Datum. A single thread of smoke rose up from a campfire by the shore.

And as the plane began its final approach, a woman by the fire got to her feet and waved.

7

ROD EXCHANGED VERY few words with Sally Linsay. Joshua suspected he had always felt uncomfortable with the tension between his mother and Sally – even though, Joshua supposed, Sally’s transient lifestyle was a lot more like Rod’s own choice than Helen’s sedentary midwifery. Rod said goodbye politely enough, and exchanged a handshake with his father.

Then Sally and Joshua stood side by side as they watched the plane climb into the sky, before it flew stepwise and out of existence. Joshua tried to close the lid on his latest cargo of regret, a feeling of another opportunity missed, somehow.

Sally let Joshua gulp down a lunch of roast rabbit leg and a cup of cold coffee, while she pulled her pack on her back and kicked out her fire.

‘No time to lose, eh, Sally? You haven’t changed.’

‘You betcha I haven’t changed. Why would I need to? Anyway you’ve been sitting on your fat ass in that plane all night, you need the exercise. Happy birthday, by the way.’

‘Thanks.’

Sally, fifty-five years old now, only looked even tougher than she had when she was younger, Joshua thought. As if she’d weathered down to some hardened nub. She said now, ‘Listen up. You want to get to the Low Earths by the evening, right? Three thousand worlds in six hours or so. We’ll need to keep up the pace, a step every few seconds. We’ll take regular breaks, we can do it.’ She eyed him. ‘Always assuming you don’t want to cheat and take a short cut.’

‘You mean, through a soft place? Not unless we have to.’

‘This is your birthday treat. Why the hell would you have to do anything?’

‘I have an appointment. I’m meeting Nelson Azikiwe for the last leg.’

‘That bore.’

‘Everybody’s a bore to you, Sally. Even me, probably.’

‘Especially you, Valienté. Don’t flatter yourself.’ She inspected him more closely, acutely. ‘Are you OK? Seriously.’

‘I’ve been having my headaches. That’s why I cut short my last sabbatical.’

‘Ah. The Silence headaches. Your legendary sensitivity to disturbances far out in the Long Earth—’

‘It’s no joke, Sally. Lobsang always said you were jealous of me for that.’

‘Huh. That master psychologist. Well, you’ve been right before—’

‘Right about First Person Singular. Right about the big troll migration back in 2040—’

‘I don’t need a précis. You have any idea what’s up this time, specifically?’

‘No,’ he said unhappily. ‘I never do.’

‘Yeah. So is it disabling? Are we going to do this walk, or what?’

Without replying, Joshua dumped the remains of his lunch, got his pack settled on his back, checked his boots, and they began.

Sally led the way on a steady plod around the lake shore. They kept back from the water edge itself where animals were likely to congregate, and away from any crocs or other hazards in the water.

They’d just keep walking around this lake, or its Long Earth foot-prints, until the evening. And every few paces, they’d take a step East, together. As easy as that. Parallel lakes, and parallel shores.

‘You shouldn’t worry about your son, you know.’

Joshua smiled. ‘You’re giving me family advice? You, no marriage, no children – a father who abandoned you until he needed you to piggy-back him across the Long Mars?’

She grunted. ‘Did you know there are Australian Aborigines up there now? Spreading out across the Long Mars. Their social structures are fit for purpose on such arid worlds, it seems.

‘And as for family advice – look, all kids rebel against how their parents did things. It’s natural. Your son’s generation, lucky for them, are growing up in a completely different environment from you and me. Entirely new challenges, new ethics. Especially since the Datum imploded and the government stopped trying to tax everybody. And for sure, the Long Earth has had a way of imposing a natural selection of the smart over the dumb, right from the beginning.’

‘I know, Sally. I was there, remember? And if the selection isn’t natural, you lend it a hand, right?’

She glared at him. ‘Somebody has to, now that even Maggie Kauffman and her flying Navy gunships are rarely to be seen.’

Joshua knew Sally was earning a living these days as a kind of professional survivor. In return for a pre-agreed fee she’d stay a few months, maybe a year, with a new community of settlers, helping them endure the most obvious dangers, avoid the first few booby-traps. For a woman who never suffered fools gladly, Joshua knew this was a tough career choice; the physical challenges would be easy for her, but it was hard for Sally to be supportive as opposed to judgemental.

But Joshua had his own contacts out in the Long Earth, and he’d heard a lot of rumours about what Sally was really up to. She was gathering a growing reputation for vigilantism. He was concerned for her, that she was losing her way. For now, however, he said nothing.

They walked into a world where the animals were comparatively thick on the ground, and drawn to the lake. Maybe there was some kind of drought on in this particular footprint. The travellers paused, sipping their own bottled water. The air felt dusty and hot. A herd of what looked like deer lapped watchfully at the water, and a giant sloth raised itself up to nibble at the curling leaves of a dying tree. Things like big opossums clustered without shyness at the sloth’s feet, browsing on the litter it dropped.

‘You know, Joshua, you and I are different from the rest. We’re not townsfolk, not Datum urbanites. But we’re not pioneers either. We’re not settlers, like your little mouse Helen.’

‘Oh, she’s no mouse. And she’s not mine any more—’

‘We’re loners. Loners just survive, they move on. They don’t build things, like the pioneers. The Long Earth is always going to have room for the likes of us. We don’t need any kind of definition. We don’t have a role. Not even to the extent that the combers have, that self-conscious lifestyle they’ve developed of deliberately walking on and on, taking nothing save the lowest hanging fruit. We’re just – us. Detached from humanity.’

‘And detached from human values? Is that what you’re trying to say?’

‘I’m saying I have my own values – and so, I think, do you.’

He studied her, trying to read her, and failing, as he always had in the twenty-plus years he’d known her. ‘Sin or not, you’re no avenging god, Sally. You need—’