The Long Earth

enormous, physically. To them it is a mix of physical and abstract. Like an approaching forest fire, maybe. A wall of pain.’
    The complaints from the fabric of the
Mark Twain
were beginning to bother Joshua. He had no idea what maximum safe stepping speed the ship was capable of. And to plummet at such a rate into entire unknown worlds, and towards an unknown danger, seemed unwise to him to say the least. The earthometers, he saw, were whirling up ever closer to the two million mark.
    But Lobsang was talking and talking, apparently oblivious to such concerns. ‘This is not the time to share all of my thinking with the two of you. Suffice it to say that it is clear we are dealing with some kind of genuine psychic phenomenon.
    ‘Here is the hypothesis. Humans broadcast their humanity in some way. We sense one another. But we have long evolved to live on a planet absolutely drenched with human thoughts. We don’t even notice it.’
    ‘Not until it’s gone,’ Joshua said.
    Sally looked at him, curious.
    ‘I suggest that once upon a time some of these creatures, elves and trolls and perhaps other variants, did occasionally step into the Datum, and perhaps occasionally hung around for a spell. Thus giving rise to volumes of myth. But this was in the days of comparatively low human population. Now the planet is knee deep in humans, and for creatures that spend most of their time in the mindless calm of woodlands and prairies, it must be as if all the world’s teenage parties are being thrown at once. So these days they stay away from the Datum. However, the stepping species migrating from the West are fleeing from something that is irrevocably pushing them
back
towards the Datum. They are caught between the hammer and the anvil. And sometimes they panic. Joshua and I have seen what happens when they panic – even trolls may be capable of harm when roused, and remember the Church of the Cosmic Confidence Trick, Joshua?’
    Joshua glanced at Sally. He would have expected nothing but scepticism from her. But, amazingly, she looked thoughtful. He prompted, ‘What are you thinking, Sally?’
    ‘That it’s all far-fetched. And yet … I mean, I’m like you, I’ll go into a city for a purpose, but while I’m in one I’m nervous as a long-tailed cat in a room full of rocking chairs. I can’t wait to get out, it
pushes
me out, back out into the empty worlds. Where I feel more comfortable.’
    ‘But you don’t run, right? And you don’t notice it the rest of the time. The way fish don’t notice water.’
    Surprisingly, Sally smiled. ‘That’s very Zen. Almost Lobsang.’ She looked at him carefully. ‘And what about you?’
    She knows, he thought. She knows all about me. And yet still he hesitated before answering.
    Then he spoke to them, on this rushing airship, more freely than he ever had to anybody, even to Sister Agnes or Officer Jansson, about his own inner sensations.
    He told them about the peculiar pressure in his head he felt every time he went back to the Datum. A reluctance, that eventually turned into a physical revulsion. ‘It’s something in my head. It’s like , you know how as a kid if you
have
to go to some party where everybody else is going to fit in, except you? Like you physically can’t take another step, like some magnetic field is pushing you away.’
    Sally shrugged. ‘I never went to many parties.’
    ‘And you’re antisocial, Joshua,’ Lobsang said. ‘I think we knew that. What’s your point?’
    ‘Here’s the thing. Whatever it means, whatever causes this, I’ve been feeling something like it
here
. On the airship. A pressure, making it harder to go on.’ He closed his eyes. ‘And it’s getting worse, the further West we go. I feel it now. Like a repulsion, deep inside. I can stand it when we stay still, but it’s harder to bear when we travel, and it worsens.’
    Lobsang asked, ‘Something out in the far West, pushing you away?’
    ‘Yes.’
    Sally asked angrily, ‘Why didn’t you tell me this before? You let me blab about the soft places, about my family’s secrets. I opened up to you,’ she said almost with a snarl. ‘And all the time you were hiding this?’
    He just looked at her. He hadn’t told her because you kept your weaknesses to yourself, in the Home, and in most places he’d had to survive in since then. ‘I’m telling you now.’
    She backed down with an effort. ‘All right,’ she said. ‘I believe you. So this is all real. I admit it