The Long Earth

transEarth Institute, an arm of the Black Corporation. The faceless office, all plasterboard and chrome, was dominated by a huge logo, a chesspiece knight. This wasn’t Joshua’s world. None of it was
his
world. In fact, when you got right down to it, he didn’t have a world; he had
all
of them.
    All of the Long Earth.
    Earths, untold Earths. More Earths than could be counted, some said. And all you had to do was walk sideways into them, one after the next, an unending chain.
    This was a source of immense irritation for experts such as Professor Wotan Ulm of Oxford University. ‘All these parallel Earths,’ he told the BBC, ‘are identical on all but the detailed level. Oh, save that they are empty. Well, actually they are full, mainly of forests and swamps. Big, dark, silent forests, deep, clinging, lethal swamps. But empty of people. The Earth is crowded, but the Long Earth is empty. This is tough luck on Adolf Hitler, who hasn’t been allowed to win his war anywhere!
    ‘It is hard for scientists even to talk about the Long Earth without babbling about m-brane manifolds and quantum multiverses. Look: perhaps the universe bifurcates every time a leaf falls, a billion new branches every instant. That’s what quantum physics seems to tell us. Oh, it is not a question of a billion realities to be experienced; the quantum states superpose, like harmonics on a single violin string. But perhaps there are times – when a volcano stirs, a comet kisses, a true love is betrayed – when you
can
get a separate experiential reality, a braid of quantum threads. And perhaps these braids are then drawn together through some higher dimension by similarity, and a chain of worlds self-organizes. Or something! Maybe it is all a dream, a collective imagining of mankind.
    ‘The truth is that we are as baffled by the phenomenon as Dante would have been if he’d suddenly been given a glimpse of Hubble’s expanding universe. Even the language we use to describe it is probably no more correct than the pack-of-cards analogy that most people feel at home with: the Long Earth as a large pack of three-dimensional sheets, stacked up in a higher-dimensional space, each card an Earth entire unto itself.
    ‘And, most significantly, to most people, the Long Earth is open. Almost anybody can travel up and down the pack, drilling, as it were , through the cards themselves. People are expanding into all that room. Of course they are! This is a primal instinct. We plains apes still fear the leopard in the dark; if we spread out he cannot take all of us.
    ‘It is all profoundly annoying. None of it fits! And why has this tremendous pack of cards been dealt to mankind just
now
, when we have never been more in need of
room
? But then science is nothing but a series of questions that lead to more questions, which is just as well, or it wouldn’t be much of a career path, would it? Well – whatever the answers to such questions, believe you me, everything is changing for mankind … Is that enough, Jocasta? Some idiot clicked a pen while I was doing the bit about Dante.’
    Of course, Joshua understood, transEarth existed to profit from all these changes. Which, presumably, was why Joshua had been brought here, more or less against his will, from a world a long way away.
    At last the door opened. A young woman came in, nursing a laptop as thin as a sheet of gold leaf. Joshua kept such a machine in the Home, a fatter, antiquated model, mostly to look up wild-food recipes. ‘Mr Valienté? It’s so kind of you to come. My name is Selena Jones. Welcome to the transEarth Institute.’
    She was certainly attractive, he thought. Joshua liked women; he remembered his few, brief relationships with pleasure. But he hadn’t spent much
time
with women, and was awkward with them. ‘Welcome? You didn’t give me a choice. You found my mailbox. That means you’re government.’
    ‘As a matter of fact, you’re wrong. We sometimes work for the government, but we’re certainly not the government.’
    ‘Legal?’
    She smiled deprecatingly. ‘Lobsang found your mailbox code.’
    ‘And who is Lobsang?’
    ‘Me,’ said the drinks machine.
    ‘You’re a drinks machine,’ said Joshua.
    ‘You are wrong in your surmise, although I could produce the drink of your choice within seconds.’
    ‘But you’ve got Coca-Cola written on you!’
    ‘Do forgive me my sense of humour. Incidentally, if you had hazarded a dollar in the hope of soda-based