Into Darkness

Greg Egan

Derived from EXAMPLE, edited by EXAMPLE

First published January 1992 in Isaac Asimov’s Science Fiction Magazine

The tone from the buzzer rises in both pitch and loudness the longer it’s on, so I leap out of bed knowing that it’s taken me less than a second to wake. I swear I was dreaming it first, though, dreaming the sound long before it was real. That’s happened a few times. Maybe it’s just a trick of the mind; maybe some dreams take shape only in the act of remembering them. Or maybe I dream it every night, every sleeping moment, just in case.

The light above the buzzer is red. Not a rehearsal.

I dress on my way across the room to thump the acknowledgement switch; as soon as the buzzer shuts off, I can hear the approaching siren. It takes me as long to lace my shoes as everything else combined. I grab my backpack from beside the bed and flick on the power. It starts flashing LEDs as it goes through its self-checking routines.

By the time I’m at the kerb, the patrol car is braking noisily, rear passenger door swinging open. I know the driver, Angelo, but I haven’t seen the other cop before. As we accelerate, a satellite view of The Intake in false-colour infrared—a pitch-black circle in a landscape of polychromatic blotches—appears on the car’s terminal. A moment later, this is replaced by a street map of the region—one of the newer far northern suburbs, all cul-de-sacs and crescents—with The Intake’s perimeter and centre marked, and a dashed line showing where The Core should be. The optimal routes are omitted; too much clutter and the mind balks. I stare at the map, trying to commit it to memory. It’s not that I won’t have access to it, inside, but it’s always faster to just know. When I close my eyes to see how I’m going, the pattern in my head looks like nothing so much as a puzzle-book maze.

We hit the freeway, and Angelo lets loose. He’s a good driver, but I sometimes wonder if this is the riskiest part of the whole business. The cop I don’t know doesn’t think so; he turns to me and says, ‘I gotta tell you one thing; I respect what you do, but you must be fucking crazy. I wouldn’t go inside that thing for a million dollars.’ Angelo grins—I catch it in the rear-view mirror—and says, ‘Hey, how much is the Nobel prize, anyway? More than a million?’

I snort. ‘I doubt it. And I don’t think they give the Nobel prize for the eight-hundred-metre steeplechase.’ The media seem to have decided to portray me as some kind of expert; I don’t know why—unless it’s because I once used the phrase ‘radially anisotropic’ in an interview. It’s true that I carried one of the first scientific ‘payloads’, but any other Runner could have done that, and these days it’s routine. The fact is, by international agreement, no one with even a microscopic chance of contributing to the theory of The Intake is allowed to risk their life by going inside. If I’m atypical in any way, it’s through a lack of relevant qualifications; most of the other volunteers have a background in the conventional rescue services.

I switch my watch into chronograph mode, and synch it to the count that the terminal’s now showing, then do the same to my backpack’s timer. Six minutes and twelve seconds. The Intake’s manifestations obey exactly the same statistics as a radioactive nucleus with a half-life of eighteen minutes; seventy-nine per cent last six minutes or more—but multiply anything by 0.962 every minute, and you wouldn’t believe how fast it can fall. I’ve memorised the probabilities right out to an hour (ten per cent), which may or may not have been a wise thing to do. Counter to intuition, The Intake does not become more dangerous as time passes, any more than a single radioactive nucleus becomes ‘more unstable’. At any given moment—assuming that it hasn’t yet vanished—it’s just as likely as ever to stick around for another eighteen minutes. A mere ten per cent of manifestations last for an hour or more—but of that ten per cent, half will still be there eighteen minutes later. The danger has not increased.

For a Runner, inside, to ask what the odds are now, he or she must be alive to pose the question, and so the probability curve must start afresh from that moment. History can’t harm you; the ‘chance’ of having survived the last x minutes is one hundred per cent, once you’ve done it. As the unknowable future becomes the unchangeable past, risk must collapse into certainty, one way or another.

Whether or not any of us really think this way is another question. You can’t help having a gut feeling that time is running out, that the odds are being whittled away. Everyone keeps track of the time since The Intake materialised, however theoretically irrelevant that is. The truth is, these abstractions make no difference in the end. You do what you can, as fast as you can, regardless.

It’s two in the morning, the freeway is empty, but it still takes me by surprise when we screech on to the exit ramp so soon. My stomach is painfully tight. I wish I felt ready, but I never do. After ten real calls, after nearly two hundred rehearsals, I never do. I always wish I had more time to compose myself, although I have no idea what state of mind I’d aim for, let alone how I’d achieve it. Some lunatic part of me is always hoping for a delay. If what I’m really hoping is that The Intake will have vanished before I can reach it, I shouldn’t be here at all.

The coordinators tell us, over and over: ‘You can back out any time you want to. Nobody would think any less of you.’ It’s true, of course (up to the point where backing out becomes physically impossible), but it’s a freedom I could do without. Retiring would be one thing, but once I’ve accepted a call I don’t want to have to waste my energy on second thoughts, I don’t want to have to endlessly reaffirm my choice. I’ve psyched myself into half believing that I couldn’t live with myself, however understanding other people might be, and that helps a little. The only trouble is, this lie might be self-fulfilling, and I really don’t want to become that kind of person.

I close my eyes, and the map appears before me. I’m a mess, there’s no denying it, but I can still do the job, I can still get results. That’s what counts.

I can tell when we’re getting close, without even searching the skyline; there are lights on in all of the houses, and families standing in their front yards. Many people wave and cheer as we pass, a sight that always depresses me. When a group of teenagers, standing on a street corner drinking beer, scream abuse and gesture obscenely, I can’t help feeling perversely encouraged.

‘Dickheads,’ mutters the cop I don’t know. I keep my mouth shut.

We take a corner, and I spot a trio of helicopters, high on my right, ascending with a huge projection screen in tow. Suddenly, a corner of the screen is obscured, and my eye extends the curve of the eclipsing object from this one tiny arc to giddy completion.

From the outside, by day, The Intake makes an impressive sight: a giant black dome, completely non-reflective, blotting out a great bite of the sky. It’s impossible not to believe that you’re confronting a massive, solid object. By night, though, it’s different. The shape is still unmistakable, cut in a velvet black that makes the darkest night seem grey, but there’s no illusion of solidity; just an awareness of a different kind of void.

The Intake has been appearing for almost ten years now. It’s always a perfect sphere, a little more than a kilometre in radius, and usually centred close to ground level. On rare occasions, it’s been known to appear out at sea, and slightly more often, on uninhabited land, but the vast majority of its incarnations take place in populated regions.

The currently favoured hypothesis is that a future civilisation tried to construct a wormhole that would let them sample the distant past, bringing specimens of ancient life into their own time to be studied. They screwed up. Both ends of the wormhole came unstuck. The thing has shrunk and deformed, from—presumably—some kind of grand temporal highway, bridging geological epochs, to a gateway that now spans less time than it would take to cross an atomic nucleus at the speed of light. One end—The Intake—is a kilometre in radius; the other is about a fifth as big, spatially concentric with the first, but displaced an almost immeasurably small time into the future. We call the inner sphere—the wormhole’s destination, which seems to be inside it, but isn’t—The Core.

Why this shrivelled-up piece of failed temporal engineering has ended up in the present era is anyone’s guess; maybe we just happened to be halfway between the original endpoints, and the thing collapsed symmetrically. Pure bad luck. The trouble is, it hasn’t quite come to rest. It materialises somewhere on the planet, remains fixed for several minutes, then loses its grip and vanishes, only to appear at a new location a fraction of a second later. Ten years of analysing the data has yielded no method for predicting successive locations, but there must be some remnant of a navigation system in action; why else would the wormhole cling to the Earth’s surface (with a marked preference for inhabited, dry land) instead of wandering off on a random course into interplanetary space? It’s as if some faithful, demented computer keeps valiantly trying to anchor The Intake to a region which might be of interest to its scholarly masters; no Palaeozoic life can be found, but twenty-first-century cities will do, since there’s nothing much else around. And every time it fails to make a permanent connection and slips off into hyperspace, with infinite dedication, and unbounded stupidity, it tries again.

Being of interest is bad news. Inside the wormhole, time is mixed with one spatial dimension, and—whether by design or physical necessity—any movement which equates to travelling from the future into the past is forbidden. Translated into the wormhole’s present geometry, this means that when The Intake materialises around you, motion away from the centre is impossible. You have an unknown time—maybe eighteen minutes, maybe more, maybe less—to navigate your way to the safety of The Core, under these bizarre conditions. What’s more, light is subject to the same effect; it only propagates inwards. Everything closer to the centre than you lies in the invisible future. You’re running into darkness.

I have heard people scoff at the notion that any of this could be difficult. I’m not quite enough of a sadist to hope that they learn the truth, first-hand.

Actually, outwards motion isn’t quite literally impossible. If it were, everyone caught in The Intake would die at once. The heart has to circulate blood, the lungs have to inhale and exhale, nerve impulses have to travel in all directions. Every single living cell relies on shuffling chemicals back and forth, and I can’t even guess what the effect would be on the molecular level, if electron clouds could fluctuate in one direction but not the reverse.

There is some leeway. Because the wormhole’s entire eight hundred metres spans such a minute time interval, the distance scale of the human body corresponds to an even shorter period—short enough for quantum effects to come into play. Quantum uncertainty in the space-time metric permits small, localised violations of the classical law’s absolute restriction.

So, instead of everyone dying on the spot, blood pressure goes up, the heart is stressed, breathing becomes laborious, and the brain may function erratically. Enzymes, hormones, and other biological molecules are all slightly deformed, causing them to bind less efficiently to their targets, interfering to some degree with every biochemical process; haemoglobin, for example, loses its grip on oxygen more easily. Water diffuses out of the body—because random thermal motion is suddenly not so random—leading to gradual dehydration.

People already in very poor health can die from these effects. Others are just made nauseous, weak and confused—on top of the inevitable shock and panic. They make bad decisions. They get trapped.

One way or another, a few hundred lives are lost, every time The Intake materialises. Intake Runners may save ten or twenty people, which I’ll admit is not much of a success rate, but until some genius works out how to rid us of the wormhole for good, it’s better than nothing.

The screen is in place high above us, when we reach the ‘South Operations Centre’—a couple of vans, stuffed with electronics, parked on someone’s front lawn. The now familiar section of street map appears, the image rock steady and in perfect focus, in spite of the fact that it’s being projected from a fourth helicopter, and all four are jittering in the powerful inwards wind. People inside can see out, of course; this map—and the others, at the other compass points—will save dozens of lives. In theory, once outdoors, it should be simple enough to head straight for The Core; after all, there’s no easier direction to find, no easier path to follow. The trouble is, a straight line inwards is likely to lead you into obstacles, and when you can’t retrace your steps, the most mundane of these can kill you.

So, the map is covered with arrows, marking the optimal routes to The Core, given the constraint of staying safely on the roads. Two more helicopters, hovering above The Intake, are doing one better: with high-velocity paint guns under computer control, and laser-ring inertial guidance systems constantly telling the shuddering computers their precise location and orientation, they’re drawing the same arrows in fluorescent/reflective paint on the invisible streets below. You can’t see the arrows ahead of you, but you can look back at the ones you’ve passed. It helps.

There’s a small crowd of coordinators, and one or two Runners, around the vans. This scene always looks forlorn to me, like some small-time rained-out amateur athletics event, air traffic notwithstanding. Angelo calls out, ‘Break a leg!’ as I run from the car. I raise a hand and wave without turning. Loudspeakers are blasting the standard advice inwards, cycling through a dozen languages. In the corner of my eye I can see a TV crew arriving. I glance at my watch. Nine minutes. I can’t help thinking, seventy-one per cent, although The Intake is, clearly, one hundred per cent still there. Someone taps me on the shoulder. Elaine. She smiles and says, ‘John, see you in The Core,’ then sprints into the wall of darkness before I can reply.

Dolores is handing out assignments on RAM. She wrote most of the software used by Intake Runners around the world, but then, she makes her living writing computer games. She’s even written a game which models The Intake itself, but sales have been less than spectacular; the reviewers decided it was in bad taste. ‘What’s next? Let’s play Airline Disaster?’ Maybe they think flight simulators should be programmed for endless calm weather. Meanwhile, televangelists sell prayers to keep the wormhole away; you just slip that credit card into the home-shopping slot for instant protection.

‘What have you got for me?’

‘Three infants.’

‘Is that all?’

‘You come late, you get the crumbs.’

I plug the cartridge into my backpack. A sector of the street map appears on the display panel, marked with three bright red dots. I strap on the pack, and then adjust the display on its movable arm so I can catch it with a sideways glance, if I have to. Electronics can be made to function reliably inside the wormhole, but everything has to be specially designed.

It’s not ten minutes, not quite. I grab a cup of water from a table beside one of the vans. A solution of mixed carbohydrates, supposedly optimised for our metabolic needs, is also on offer, but the one time I tried it I was sorry; my gut isn’t interested in absorbing anything at this stage, optimised or not. There’s coffee too, but the very last thing I need right now is a stimulant. Gulping down the water, I hear my name, and I can’t help tuning in to the TV reporter’s spiel.

‘… John Nately, high-school science teacher and unlikely hero, embarking on this, his eleventh call as a volunteer Intake Runner. If he survives tonight, he’ll have set a new national record—but of course, the odds of making it through grow slimmer with every call, and by now…’

The moron is spouting crap—the odds do not grow slimmer, a veteran faces no extra risk—but this isn’t the time to set him straight. I swing my arms for a few seconds in a half-hearted warm-up, but there’s not much point; every muscle in my body is tense, and will be for the next eight hundred metres, whatever I do. I try to blank my mind and just concentrate on the run-up—the faster you hit The Intake, the less of a shock it is—and before I can ask myself, for the first time tonight, what the fuck I’m really doing here, I’ve left the isotropic universe behind, and the question is academic.

The darkness doesn’t swallow you. Perhaps that’s the strangest part of all. You’ve seen it swallow other Runners; why doesn’t it swallow you? Instead, it recedes from your every step. The borderline isn’t absolute; quantum fuzziness produces a gradual fade-out, stretching visibility about as far as each extended foot. By day, this is completely surreal, and people have been known to suffer fits and psychotic episodes at the sight of the void’s apparent retreat. By night, it seems merely implausible, like chasing an intelligent fog.

At the start, it’s almost too easy; memories of pain and fatigue seem ludicrous. Thanks to frequent rehearsals in a compression harness, the pattern of resistance as I breathe is almost familiar. Runners once took drugs to lower their blood pressure, but with sufficient training, the body’s own vasoregulatory system can be made flexible enough to cope with the stress, unaided. The odd tugging sensation on each leg as I bring it forward would probably drive me mad, if I didn’t (crudely) understand the reason for it: inwards motion is resisted, when pulling, rather than pushing, is involved, because information travels outwards. If I trailed a ten-metre rope behind me, I wouldn’t be able to take a single step; pulling on the rope would pass information about my motion from where I am to a point further out. That’s forbidden, and it’s only the quantum leeway that lets me drag each foot forwards at all.

The street curves gently to the right, gradually losing its radial orientation, but there’s no convenient turn-off yet. I stay in the middle of the road, straddling the double white line, as the border between past and future swings to the left. The road surface seems always to slope towards the darkness, but that’s just another wormhole effect; the bias in thermal molecular motion—cause of the inwards wind, and slow dehydration—produces a force, or pseudo-force, on solid objects, too, tilting the apparent vertical.

‘—me! Please!’

A man’s voice, desperate and bewildered—and almost indignant, as if he can’t help believing that I must have heard him all along, that I must have been feigning deafness out of malice or indifference. I turn, without slowing; I’ve learnt to do it in a way that makes me only slightly dizzy. Everything appears almost normal, looking outwards—apart from the fact that the streetlights are out, and so most illumination is from helicopter floodlights and the giant street map in the sky. The cry came from a bus shelter, all vandal-proof plastic and reinforced glass, at least five metres behind me, now; it might as well be on Mars. Wire mesh covers the glass; I can just make out the figure behind it, a faint silhouette.

‘Help me!’

Mercifully—for me—I’ve vanished into this man’s darkness; I don’t have to think of a gesture to make, an expression to put on my face, appropriate to the situation. I turn away, and pick up speed. I’m not inured to the death of strangers, but I am inured to my helplessness.

After ten years of The Intake, there are international standards for painted markings on the ground around every potential hazard in public open space. Like all the other measures, it helps, slightly. There are standards, too, for eventually eliminating the hazards—designing out the corners where people can be trapped—but that’s going to cost billions, and take decades, and won’t even touch the real problem: interiors. I’ve seen demonstration trap-free houses and office blocks, with doors, or curtained doorways, in every corner of every room, but the style hasn’t exactly caught on. My own house is far from ideal; after getting quotes for alterations, I decided that the cheapest solution was to keep a sledgehammer beside every wall.

I turn left, just in time to see a trail of glowing arrows hiss into place on the road behind me.

I’m almost at my first assignment. I tap a button on my backpack and peer sideways at the display, as it switches to a plan of the target house. As soon as The Intake’s position is known, Dolores’s software starts hunting through databases, assembling a list of locations where there’s a reasonable chance that we can do some good. Our information is never complete, and sometimes just plain wrong; census data is often out of date, building plans can be inaccurate, mis-filed, or simply missing—but it beats walking blind into houses chosen at random.

I slow almost to a walk, two houses before the target, to give myself time to grow used to the effects. Running inwards lessens the outwards components—relative to the wormhole—of the body’s cyclic motions; slowing down always feels like precisely the wrong thing to do. I often dream of running through a narrow canyon, no wider than my shoulders, whose walls will stay apart only so long as I move fast enough; that’s what my body thinks of slowing down.

The street here lies about thirty degrees off radial. I cross the front lawn of the neighbouring house, then step over a knee-high brick wall. At this angle, there are few surprises; most of what’s hidden is so easy to extrapolate that it almost seems visible in the mind’s eye. A corner of the target house emerges from the darkness on my left; I get my bearings from it and head straight for a side window. Entry by the front door would cost me access to almost half of the house, including the bedroom which Dolores’s highly erratic Room Use Predictor nominates as the one most likely to be the child’s. People can file room-use information with us directly, but few bother.

I smash the glass with a crowbar, open the window, and clamber through. I leave a small electric lamp on the windowsill—carrying it with me would render it useless—and move slowly into the room. I’m already starting to feel dizzy and nauseous, but I force myself to concentrate. One step too many, and the rescue becomes ten times more difficult. Two steps, and it’s impossible.

It’s clear that I have the right room when a dresser is revealed, piled with plastic toys, talcum powder, baby shampoo, and other paraphernalia spilling on to the floor. Then a corner of the crib appears on my left, pointed at an unexpected angle; the thing was probably neatly parallel to the wall to start with, but slid unevenly under the inwards force. I sidle up to it, then inch forwards, until a lump beneath the blanket comes into view. I hate this moment, but the longer I wait, the harder it gets. I reach sideways and lift the child, bringing the blanket with it. I kick the crib aside, then walk forwards, slowly bending my arms, until I can slip the child into the harness on my chest. An adult is strong enough to drag a small baby a short distance outwards. It’s usually fatal.

The kid hasn’t stirred; he or she is unconscious, but breathing. I shudder briefly, a kind of shorthand emotional catharsis, then I start moving. I glance at the display to recheck the way out, and finally let myself notice the time. Thirteen minutes. Sixty-one per cent. More to the point, The Core is just two or three minutes away, downhill, nonstop. One successful assignment means ditching the rest. There’s no alternative; you can’t lug a child with you, in and out of buildings; you can’t even put it down somewhere and come back for it later.

As I step through the front door, the sense of relief leaves me giddy. Either that, or renewed cerebral blood flow. I pick up speed as I cross the lawn—and catch a glimpse of a woman, shouting, ‘Wait!

Stop!’

I slow down; she catches up with me. I put a hand on her shoulder and propel her slightly ahead of me, then say, ‘Keep moving, as fast as you can. When you want to speak, fall behind me. I’ll do the same. OK?’

I move ahead of her. She says, ‘That’s my daughter you’ve got. Is she all right? Oh, please ... Is she alive?’

‘She’s fine. Stay calm. We just have to get her to The Core now. OK?’

‘I want to hold her. I want to take her.’

‘Wait until we’re safe.’

‘I want to take her there myself.’

Shit. I glance at her sideways. Her face is glistening with sweat and tears. One of her arms is bruised and blotchy, the usual symptom of trying to reach out to something unreachable.

‘I really think it would be better to wait.’

‘What right have you got? She’s my daughter! Give her to me!’ The woman is indignant, but remarkably lucid, considering what she’s been through. I can’t imagine what it must have felt like, to stand by that house, hoping insanely for some kind of miracle, while everyone in the neighbourhood fled past her, and the side effects made her sicker and sicker. However pointless, however idiotic her courage, I can’t help admiring it.

I’m lucky. My ex-wife, and our son and daughter, live halfway across town from me. I have no friends who live nearby. My emotional geography is very carefully arranged; I don’t give a shit about anyone who I could end up unable to save.

So what do I do—sprint away from her, leave her running after me, screaming? Maybe I should. If I gave her the child, though, I could check out one more house.

‘Do you know how to handle her? Never try to move her backwards, away from the darkness. Never.’

‘I know that. I’ve read all the articles. I know what you’re meant to do.’

‘ OK.’ I must be crazy. We slow down to a walk, and I pass the child to her, lowering it into her arms from beside her. I realise, almost too late, that we’re at the turn-off for the second house. As the woman vanishes into the darkness, I yell after her, ‘Run! Follow the arrows, and run!’

I check the time. Fifteen minutes already, with all that stuffing around. I’m still alive, though—so the odds now are, as always, fifty-fifty that the wormhole will last another eighteen minutes. Of course I could die at any second—but that was equally true when I first stepped inside. I’m no greater fool now than I was then. For what that’s worth.

The second house is empty, and it’s easy to see why. The computer’s guess for the nursery is in fact a study, and the parents’ bedroom is outward’s of the child’s. Windows are open, clearly showing the path they must have taken.

A strange mood overtakes me, as I leave the house behind. The inwards wind seems stronger than ever, the road turns straight into the darkness, and I feel an inexplicable tranquillity wash over me. I’m moving as fast as I can, but the edge of latent panic, of sudden death, is gone. My lungs, my muscles, are battling all the same restraints, but I feel curiously detached from them; aware of the pain and effort, yet somehow uninvolved.

The truth is, I know exactly why I’m here. I can never quite admit it, outside—it seems too whimsical, too bizarre. Of course I’m glad to save lives, and maybe that’s grown to be part of it. No doubt I also crave to be thought of as a hero. The real reason, though, is too strange to be judged either selfless or vain:

The wormhole makes tangible the most basic truths of existence. You cannot see the future. You cannot change the past. All of life consists of running into darkness. This is why I’m here.

My body grows, not numb, but separate, a puppet dancing and twitching on a treadmill. I snap out of this and check the map, not a moment too soon. I have to turn right, sharply, which puts an end to any risk of somnambulism. Looking up at the bisected world makes my head pound, so I stare at my feet, and try to recall if the pooling of blood in my left hemisphere ought to make me more rational, or less.

The third house is in a borderline situation. The parents’ bedroom is slightly outwards from the child’s, but the doorway gives access to only half the room. I enter through a window that the parents could not have used.

The child is dead. I see the blood before anything else. I feel, suddenly, very tired. A slit of the doorway is visible, and I know what must have happened. The mother or father edged their way in, and found they could just reach the child—could take hold of one hand, but no more. Pulling inwards is resisted, but people find that confusing; they don’t expect it, and when it happens, they fight it. When you want to snatch someone you love out of the jaws of danger, you pull with all your strength.

The door is an easy exit for me, but less so for anyone who came in that way—especially someone in the throes of grief. I stare into the darkness of the room’s inwards corner, and yell, ‘Crouch down, as low as you can,’ then mime doing so. I pluck the demolition gun from my backpack, and aim high. The recoil, in normal space, would send me sprawling; here it’s a mere thump.

I step forward, giving up my own chance to use the door. There’s no immediate sign that I’ve just blasted a metre-wide hole in the wall; virtually all of the dust and debris is on the inwards side. I finally reach a man kneeling in the corner, his hands on his head; for a brief moment I think he’s alive, that he took this position to shield himself from the blast. No pulse, no respiration. A dozen broken ribs, probably; I’m not inclined to check. Some people can last for an hour, pinned between walls of brick and an invisible, third wall that follows them ruthlessly into the corner, every time they slip, every time they give ground. Some people, though, do exactly the worst thing; they squeeze themselves into the inward-most part of their prison, obeying some instinct which, I’m sure, makes sense at the time.

Or maybe he wasn’t confused at all. Maybe he just wanted it to be over.

I hoist myself through the hole in the wall. I stagger through the kitchen. The fucking plan is wrong wrong wrong, a door I’m expecting doesn’t exist. I smash the kitchen window, then cut my hand on the way out.

I refuse to glance at the map. I don’t want to know the time. Now that I’m alone, with no purpose left but saving myself, everything is jinxed. I stare at the ground, at the fleeting magic golden arrows, trying not to count them.

One glimpse of a festering hamburger discarded on the road, and I find myself throwing up. Common sense tells me to turn and face backwards, but I’m not quite that stupid. The acid in my throat and nose brings tears to my eyes. As I shake them away, something impossible happens.

A brilliant blue light appears, high up in the darkness ahead, dazzling my dark-adapted eyes. I shield my face, then peer between my fingers. As I grow used to the glare, I start to make out details.

A cluster of long, thin, luminous cylinders is hanging in the sky, like some mad upside-down pipe organ built of glass, bathed in glowing plasma. The light it casts does nothing to reveal the houses and streets below. I must be hallucinating; I’ve seen shapes in the darkness before, although never anything so spectacular, so persistent. I run faster, in the hope of clearing my head. The apparition doesn’t vanish, or waver; it merely grows closer.

I halt, shaking uncontrollably. I stare into the impossible light. What if it’s not in my head? There’s only one possible explanation. Some component of the wormhole’s hidden machinery has revealed itself. The idiot navigator is showing me its worthless soul.

With one voice in my skull screaming, No! and another calmly asserting that I have no choice, that this chance might never come again, I draw the demolition gun, take aim, and fire. As if some puny weapon in the hands of an amoeba could scratch the shimmering artifact of a civilisation whose failures leave us cowering in awe.

The structure shatters and implodes in silence. The light contracts to a blinding pinprick, burning itself into my vision. Only when I turn my head am I certain that the real light is gone.

I start running again. Terrified, elated. I have no idea what I’ve done, but the wormhole is, so far, unchanged. The afterimage lingers in the darkness, with nothing to wipe it from my sight. Can hallucinations leave an afterimage? Did the navigator choose to expose itself, choose to let me destroy it?

I trip on something and stagger, but catch myself from falling. I turn and see a man crawling down the road, and I bring myself to a rapid halt, astonished by such a mundane sight after my transcendental encounter. The man’s legs have been amputated at the thighs; he’s dragging himself along with his arms alone. That would be hard enough in normal space, but here, the effort must almost be killing him.

There are special wheelchairs which can function in the wormhole (wheels bigger than a certain size buckle and deform if the chair stalls) and if we know we’ll need one, we bring one in, but they’re too heavy for every Runner to carry one just in case.

The man lifts his head and yells, ‘Keep going! Stupid fucker!’ without the least sign of doubt that he’s not just shouting at empty space. I stare at him and wonder why I don’t take the advice. He’s huge: big-boned and heavily muscled, with plenty of fat on top of that. I doubt that I could lift him—and I’m certain that if I could, I’d stagger along more slowly than he’s crawling.

Inspiration strikes. I’m in luck, too; a sideways glance reveals a house, with the front door invisible but clearly only a metre or two inwards of where I am now. I smash the hinges with a hammer and chisel, then manoeuvre the door out of the frame and back to the road. The man has already caught up with me. I bend down and tap him on the shoulder. ‘Want to try sledding?’

I step inwards in time to hear part of a string of obscenities, and to catch an unwelcome close-up of his bloody forearms. I throw the door down on to the road ahead of him. He keeps moving; I wait until he can hear me again.

‘Yes or no?’

‘Yes,’ he mutters.

It’s awkward, but it works. He sits on the door, leaning back on his arms. I run behind, bent over, my hands on his shoulders, pushing. Pushing is the one action the wormhole doesn’t fight, and the inwards force makes it downhill all the way. Sometimes the door slides so fast that I have to let go for a second or two, to keep from overbalancing.

I don’t need to look at the map. I know the map, I know precisely where we are; The Core is less than a hundred metres away. In my head I recite an incantation: The danger does not increase. The danger does not increase. And in my heart I know that the whole conceit of ‘probability’ is meaningless; the wormhole is reading my mind, waiting for the first sign of hope, and whether that comes fifty metres, or ten metres, or two metres from safety, that’s when it will take me.

Some part of me calmly judges the distance we cover, and counts: Ninety-three, ninety-two, ninety-one… I mumble random numbers to myself, and when that fails, I reset the count arbitrarily: Eighty-one, eighty-seven, eighty-six, eighty-five, eighty-nine…

A new universe, of light, stale air, noise-and people, countless people—explodes into being around me. I keep pushing the man on the door, until someone runs towards me and gently prises me away. Elaine. She guides me over to the front steps of a house, while another Runner with a first-aid kit approaches my bloodied passenger. Groups of people stand or sit around electric lanterns, filling the streets and front yards as far as I can see. I point them out to Elaine. ‘Look. Aren’t they beautiful?’

‘John? You OK? Get your breath. It’s over.’

‘Oh, fuck.’ I glance at my watch. ‘Twenty-one minutes. Forty-five per cent.’ I laugh, hysterically. ‘I was afraid of forty-five per cent?’

My heart is working twice as hard as it needs to. I pace for a while, until the dizziness begins to subside. Then I flop down on the steps beside Elaine.

A while later, I ask, ‘Any others still out there?’

‘No.’

‘Great.’ I’m starting to feel almost lucid. ‘So… how did you go?’

She shrugs. ‘OK. A sweet little girl. She’s with her parents somewhere round here. No complications; favourable geometry.’ She shrugs again. Elaine is like that; favourable geometry or not, it’s never a big deal.

I recount my own experience, leaving out the apparition. I should talk to the medical people first, straighten out what kind of hallucination is or isn’t possible, before I start spreading the word that I took a pot shot at a glowing blue pipe organ from the future.

Anyway, if I did any good, I’ll know soon enough. If The Intake does start drifting away from the planet, that shouldn’t take long to make news; I have no idea at what rate the parting would take place, but surely the very next manifestation would be highly unlikely to be on the Earth’s surface. Deep in the crust, or halfway into space—

I shake my head. There’s no use building up my hopes, prematurely, when I’m still not sure that any of it was real.

Elaine says, ‘What?’

‘Nothing.’

I check the time again. Twenty-nine minutes. Thirty-three per cent. I glance down the street impatiently. We can see out into the wormhole, of course, but the border is clearly delineated by the sudden drop in illumination, once outward-bound light can no longer penetrate. When The Intake moves on, though, it won’t be a matter of looking for subtle shifts in the lighting. While the wormhole is in place, its effects violate the Second Law of Thermodynamics (biased thermal motion, for a start, clearly decreases entropy). In parting, it more than makes amends; it radially homogenises the space it occupied, down to a length scale of about a micron. To the rock two hundred metres beneath us, and the atmosphere above—both already highly uniform—this will make little difference, but every house, every garden, every blade of grass—every structure visible to the naked eye—will vanish. Nothing will remain but radial streaks of fine dust, swirling out as the high-pressure air in The Core is finally free to escape.

Thirty-five minutes. Twenty-six per cent. I look around at the weary survivors; even for those who left no family or friends behind, the sense of relief and thankfulness at having reached safety has no doubt faded. They—we—just want the waiting to be over. Everything about the passage of time, everything about the wormhole’s uncertain duration, has reversed its significance. Yes, the thing might set us free at any moment—but so long as it hasn’t, we’re as likely as not to be stuck here for eighteen more minutes.

Forty minutes. Twenty-one per cent.

‘Ears are really going to pop tonight,’ I say. Or worse; on rare occasions, the pressure in The Core can grow so high that the subsequent decompression gives rise to the bends. That’s at least another hour away, though—and if it started to become a real possibility, they’d do an air drop of a drug that would cushion us from the effect.

Fifty minutes. Fifteen per cent.

Everyone is silent now; even the children have stopped crying.

‘What’s your record?’ I ask Elaine.

She rolls her eyes. ‘Fifty-six minutes. You were there. Four years ago.’

‘Yeah. I remember.’

‘Just relax. Be patient.’

‘Don’t you feel a little silly? I mean, if I’d known, I would have taken my time.’

One hour. Ten per cent. Elaine has dozed off, her head against my shoulder. I’m starting to feel drowsy myself, but a nagging thought keeps me awake.

I’ve always assumed that the wormhole moves because its efforts to stay put eventually fail—but what if the truth is precisely the opposite? What if it moves because its efforts to move have always, eventually, succeeded? What if the navigator breaks away to try again, as quickly as it can—but its crippled machinery can do no better than a fifty-fifty chance of success, for every eighteen minutes of striving?

Maybe I’ve put an end to that striving. Maybe I’ve brought The Intake, finally, to rest.

Eventually, the pressure itself can grow high enough to be fatal. It takes almost five hours, it’s a one-in-one-hundred-thousand case, but it has happened once already, there’s no reason at all it couldn’t happen again. That’s what bothers me most: I’d never know. Even if I saw people dying around me, the moment would never arrive when I knew, for certain, that this was the final price.

Elaine stirs without opening her eyes. ‘Still?’

‘Yeah.’ I put an arm around her; she doesn’t seem to mind.

‘Well. Don’t forget to wake me when it’s over.’