Greg Egan - Quarantine

The terminal's image flickers and dies. I thump it, and it comes back to life — but then the text wavers and disintegrates into individual letters, which slowly drift apart like flotsam, or space debris, then leave the surface of the screen itself and float out into the room. I reach out and sweep up a handful; they melt on my palm like snowflakes.

I look out across the city. Advertising holograms are fragmenting, dissolving, mutating. Some have degenerated into abstract streaks of vivid colour, slowly bleeding into the night air; others remain identifiable, if surreal: images ofjets are growing scales and claws; beaming children are regressing into translucent pink embryos; a giant stream of Coca-Cola, endlessly flowing into a pair of disembodied lips, is blazing like napalm, lighting the buildings around it, sending a plume of thick black smoke twisting up into the sky.

There's an old man waiting for the elevator. I greet him; he just stares at me, wild-eyed. I hit the call button, but the status display shows nothing but a stream of random symbols, with occasional snatches of pai-hua too brief for me to translate. The man whispers something in Cantonese: It knows my thoughts. I turn to him, and he starts weeping. I try to think of a way to ease his distress, to explain what's happening, but I don't know where to begin — or what comfort it would bring him.

I take the stairs.

Out on the street, the crowds are subdued — quieter than I've ever seen them. All along I've been expecting hysteria and violence, but people seem to be mesmerized, walking in a dream. The transformed billboards make a bizarre spectacle, but they don't explain this mood. The mutating holograms and pyrotechnics could be nothing but an elaborate prank; surely nobody can yet have guessed what they presage.

No? Their smeared selves might have circled the globe, might already have linked, intermittently, into a mind more complex than the Earth has ever known. Who am I to know what insights might have been passed down to the collapsed mode?

In Observatory Road, I see a flowering vine burst from the pavement and dance like a snake. Amidst the dazed, blank-faced spectators, two small children are laughing and clapping with delight; perhaps they're choosing this event. The petals of the white blossoms form into luminous butterflies, which flutter away above the heads of the crowd; but the flowers remain intact, endlessly renewed.

Which is most likely: an eigenstate actually containing this feat — or one in which every witness is merely hallucinating it? I cling to the distinction, stubbornly — although I don't know how much longer it can last.

I turn away — to see a young man levitating, curled up and spinning head over heels in midair, eyes closed, smiling blissftilly. People watch him politely, as if he were a busker juggling or stilt-walking. One old woman takes root in the ground, the cloth of her trousers and the skin of her legs melting together into bark. Another woman is turning into a statue of glass, a faint flesh-coloured hue retreating from her limbs into her torso, then fading completely. What version of her could have chosen this suicidal outcome? But the 'statue' stretches its arms wide, then strides purposefully away. I try to follow it, but it vanishes into the crowd. I keep walking.

In places, the streetlights are blazing like tiny suns; a hundred metres on, the city is in darkness. I turn into an alley and And myself wading waist-deep in gold coins. I lift a handful; they're as heavy, as cool, as solid, as the real thing ought to be. I shouldn't be able to take a step, but I walk as easily as if there were nothing blocking my way.

I emerge onto a brightly lit street where it's raining blood — coarse dark stinking drops. People stand shielding their faces, screaming, or huddle on the ground, shaking and whimpering. What is this — some smeared lunatic's vision of the end of the world? Will every insane eschatology ever dreamt of be unleashed in these last hours? Or is this nothing but an accident, an unintended glitch? Many of the smeared humans could still be inexperienced, and isolated — maybe we're collapsing them unawares, constructing a mosaic reality from a series of random snapshots of their first, infantile explorations of the space of eigenstates. I stand and watch, helplessly, until the blood in my eyes begins to blind me.

A block away, it's raining clear, sweet water, and people are turning enraptured faces to the sky to drink.

The streets seethe with transformation. Some people's features are shifting, flowing smoothly or jumping between alternatives; walking in a daze, they seem oblivious, and I touch my own face, wondering if the same thing is happening to me. Vegetation is sprouting everywhere — patches of wheat, sugar cane, bamboo; stretches of wild-looking tropical undergrowth. Some stalls are simply crumbling into fine dust; others are mutating into exotic architectural pastiche — and the walls of one have turned to flesh, blood visibly pulsing through veins as thick as my arm. I stare up at the skyscrapers, most of them surreally intact — but even as I wonder at this, the fractal cladding on one tower starts drifting down like confetti.

Within a block of ASR, I catch sight of Po-kwai sitting on the pavement in front of a food stall, staring with a fixed gaze into the crowd. When I touch her shoulder, she looks up at me, then jerks away.

'Hey. It's me. Nick.'

'Nick?' She reaches up and touches my pale hand gingerly; the sight of it seems to horrify her. She says, 'I did this to you. I'm sorry.'

I laugh. 'What do you mean? I did it to myself. The quickest disguise I could think of, that's all.' I sit down beside her.

She gestures at the crowd, and says numbly, 'I'm destroying the city, I'm turning everyone into freaks. And I can't stop it. I've tried, but I can't stop it.'

I take her by the shoulders, turn her to face me. She cringes, but meets my eyes. 'Listen: none of this is your fault.'

She makes a strangled, whimpering sound, then almost laughs. 'No? Who else do you know who could do this?'

For a moment, I think: Why bother explaining anything? In an hour or two, it will make no difference. She may be suffering now — but how much consolation will the truth be?

But then I steel myself, and set about answering her question.

At first, she seems almost oblivious to my words — but slowly, the logic of what I'm saying penetrates her state of shock and the stupor of misplaced guilt. By the time I reach my encounter with Laura in the vault, the old Po-kwai is back.

'She blew the tranquillizer back into the bottle?' She nods, smiling faintly. 'Well, why not? No collapse, no time asymmetry.'

'That's exactly what Lui said.'

'Lui? When?'

'I'll come to that.'

So far as she knows, there were no bombs discovered in ASR the night of the break-in; when she spoke to Lee Hing-cheung in the morning, he told her that I'd gone missing, but claimed that nobody knew why. Perhaps she was kept in the dark — but it's just as likely that Lui himself arranged my collapse, and lied to me one more time.

When I describe the release of the Endamoeba, and my unexpected survival, she says, 'You may be wrong to blame your own smeared self. What could he do to resist a creature twelve billion times stronger than he was?'

'What do you mean?'

'The entire planet, the smeared human race — '

'But they weren't … they still aren't. Not the whole planet, even now — '

'No — but if they will be, or might be, don't you think they could choose their past? You know what one smeared human can do — don't you think an amalgam of twelve billion would be able to tunnel its way into existence, by whatever means that would take? The versions of you who prevented the spill would have ended up collapsed, uncorrelated with anyone else — but the versions who failed would have been linked to all this.. ' — she gestures at the chaos around us — 'in the sway of at least a few thousand smeared people … and whatever's yet to come. It found a way to happen, and you were part of it, that's all.'