Time to go. The aliens presumably knew it was time to go. Everyone can remember the moment when they quit the planet. When they quit us. And just as with the Kennedy assassination, everyone knows what they were doing at the time it happened: they were sleeping.

The aliens appeared to everyone in a dream. Not the same dream exactly, but almost. You see, the aliens had to take some form in which to say farewell. For some it was a grandmother, for others a long-lost friend; for others still, a pet dog they'd had as a kid: for me my beloved collie, Nelly, long dead. But the message was the same. Thank you for hosting us, they said. We're very grateful, they said. But we've had enough, they said.

They were apologetic that their stay was so brief. Five hundred thousand years residing inside our heads was, for them, a regrettably short stay. The twinkle of an eye. It was short but interesting, they said. But they dearly hoped that we had enjoyed the fruits of their presence as much as they had enjoyed an exhilarating ride.

Everyone remembers being addressed in the same way, whether by grandmother or dog. Polite, somewhat formal, slightly abashed. Then the dream image had transformed into a cube of black light on a black background, before infolding into complete absence. The world awoke to a stunned comprehension of what had happened.

Since which time no one has dreamed.

Not a flicker. Lacunæ on a global scale. A collective lobotomy.

I perch on the edge of Mandy's bed, just watching her. In the moment of observing her sleep her room becomes a peaceful chapel or a quiet temple. Wind chimes tinkle softly at the window open a little to the night air. I sense her sleeping spirit at large, roaming, restless, looking for something, a Neverland, a Narnia. She's flying, but she can't find anywhere to land. I love her so much I could cry. She's six years old, and she has never dreamed.

I have this confession to make: in the dark, at night, while she's sleeping, I whisper things in the delicate conch of my sleeping child's ear. Any things. Remembered fables. Old tales. Strange stories. Religious parables. Fragments. Anything that occurs to me. Heaven knows why, but the other day I heard myself saying Allah is great, there is no God but Allah and Mohammed is his prophet. Then I sang her a song in French about dancing on the bridge of Avignon.

Trying to create dreams for her. Trying to pierce the shell, hole the ice.

It took us a while to work out that the aliens hadn't stolen our dreams. The aliens were the dreams. It was difficult to understand initially, generations of us brought up on notions of aliens as basically humanoid with latex rubber heads, or with eggshell-blue skin, or as disembodied human brains encased in a pink gas.

The aliens residing in the consciousness of humanity for half a million years were a benevolent virus. They needed symbiosis, a host to achieve sentience, and that is what we gave them. What did they give us in return? Stories, music, religion. Tools, scientific ideas. Jokes, connections. The synaptic fire.

After their departure they became known to us as Prometheans.

Since then our stories have dried up. Our music has frozen. Our science is arrested. No one has had an original notion in seven years. We are lodged in the mud of time, fossilized. We are consigned to limbo, and the cold wind of uncreation howls in our ears like a demon. Our species, all of humanity, has become the preterite, the passed over. Our psychic teeth, pulled.

And at nights I whisper in my child's tender ear, trying and failing to incubate the glory of dreaming.

We are post-dreaming now, of course. Almost a new way of dating human history, ante- and post-dreaming. For academics, at any rate. The huge joke (I use the word loosely) is that in the entire field of intellectual endeavor only certain academics—critical theorists, social commentators, and cultural analysts—proceed as if nothing has happened, busily producing unfathomable papers on post-dreaming society.

Of course, not everyone buys the idea that we've lost it. Creativity, I mean. Originality. Innovation. Breakthrough. Those slavering puppies up at the University, for example, publishing their breathtakingly incomprehensible theses and self-serving tracts. But they're about the only ones. Hence the spectacle of six-year-old prodigies conning huge audiences desperate for the succor of the new.

Myra is thinking about something. She returns from the bathroom stroking her belly, two deep vertical creases between her eyebrows. "Out with it," I say.

She sits on the bed again, but with her back to me. "What if," she begins; "what if there were not innumerable aliens?"

I think I know what's coming. It has occurred to me already.

"I mean," she continues, "it would be odd, wouldn't it, if there were exactly the same number of aliens as there were people, and they just happened to match up, one apiece as it were. Are you with me?"

"Yes. Go on."

"So what if really there was only one alien. Inhabiting all of us. And that single alien decided to leave us. That would make more sense, wouldn't it?"

"It's a thought," I say, trying to sound light.

"Then that single alien who left us. Might that be what we've always called God?"

This is too complicated. I don't want to think about this, so I just kiss Myra and go downstairs to make some coffee.

I think this might be worse than the apocalyptic ending. The absence of poetry, of music, of narrative; this muted fanfare; the end of the never-ending movie. Not by fire or ice, but by indifference. An indifference that leaves us at the mercy of eternity.

Mandy is up and awake. Warm spring sunlight streams through the windows. She has the door open and is running for the swing I erected for her under the big old lilac tree. I leave the coffee to bubble and follow her out. The lilac flower is rampant, intoxicating.

Mandy sees me. She giggles. "Push me, Daddy! Come on!"

And I push her back and forth, and she moves from shadow into light with each swing. She wants to go dangerously high. "Faster, Daddy, Faster!"

Then I see the expression change on her face, and I step back to allow the swing to slow. "What is it?"

She spits something into her hand, and it's with relief I see it's only a milk tooth, slightly bloody at the root. It's her last one. She hands me the milk tooth as if she's trusting me with a precious stone or a talisman. I'm not sure what to do with it.

"Push me again! Higher! Higher!"

Mandy swings from shadow into the dappled morning sunlight, giggling, calling for me to push her higher and higher, and I clutch Mandy's milk tooth, a droplet of dew in my fist, and I think: Is it one alien? Or is it one for each of us? And I wonder what I'm going to tell Mandy come the day she asks me.

Myra comes out to us in her silk kimono, sleepily pushing a stray curl behind her ear. Mandy jumps off the swing to let her mother sit, a sincere gesture but one copied from adults around her these last couple of months. But she wants to push Myra on the swing.

"Gently," Myra says. "Just gently. I don't want to go high."

I go back in and bring out the coffee on a tray. Mandy pushes Myra gently back and forth on the swing, babbling happily, and I notice Myra is frowning. She mouths something at me and points to her ear, indicating I should listen.

"… And she said they were sorry. It was a long time. They wouldn't normally have gone such a long time and they didn't like to leave for longer periods than they had stayed, but they couldn't help it and anyway a long time ago is the same as the near future for them and tomorrow is half the length of only a part of yesterday and—"

I stop Mandy from talking and I stall the swing. "Who? Who said this?"

"Nelly," says Mandy still intent on pushing Myra back and forth; and the overpowering scent of the lilac makes me feel giddy and I say, "Who is Nelly?"

"Don't be silly Daddy, you know Nelly. She's a dog. She was your dog when you were a little boy. Have you still got my tooth?"

"Yes, yes, I've still got it here," and I'm holding this tray of coffee and I don't know what to do with it. "When did Nelly tell you this?"

"In the night while I was asleep, Nelly came and told me she was sorry to be away so long but she was back and all her friends would come back—

"Jonathan!" says Myra, but I'm too interested in what Mandy is saying to look up.

I sweep Mandy up in my arms and hurry back inside, where I switch on the television. Mandy is still speaking. "—And I had a little talk with Selina in Mummy's tummy because I know she's a girl though you don't know and—"

"Jonathan!" Myra calls from the garden, but it's all over the television. Reports flooding in from Auckland and Fiji, from Vladivostok and Brisbane, from Osaka and Jakarta! And from Islamabad and Nairobi, from Israel and Cairo, Eastern Europe, anyplace where people go to sleep and wake up before we do, and nearer to home, too, people waking from dreaming, rushing out into the streets in tears and madness just to try to recount what has happened to them in the night, not everyone, to be sure, but millions, yes, millions of people, maybe half the global population, dreaming dreams, gut-spilling their experiences as the report sweeps across the globe like the shadow of an eclipse, or a tsunami of unparalleled joy, or a single unbearably beautiful musical note resonating around the planet and I don't know if it was all a warning, or a punishment or an aberration but whatever it was we are going to be allowed to dream again, dream and create, and I know that this time we need to be more careful but my heart is bursting as I understand implicitly that we are to be given back our wings.

"Jonathan!"

I rush back out into the garden and Myra is gazing at me with a strange expression, half desperation, half appeal, and her kimono has fallen open and the sunlight flares on a mercurial rivulet along her thigh and it has started and I want to put down the coffee and to listen more to Mandy and to watch the sensational news reports on TV and to get my wife to hospital and I want to hand back the tooth and I'm staring, staring at the heraldic trickle, the catch-light of the silver manifesto, unable to do anything, paralyzed by the torrent of words my daughter is speaking while I am drunk on lilac and imminence.

"Jonathan," Myra says firmly, hauling herself out of the swing, "just put the coffee down."

So I put the tray of coffee down on the grass and I go and get the pre-packed bags and when I've got the car ready Myra and Mandy get in.

"Selina will be my sister, won't she?" says Mandy.

"Yes. Fasten your seat belt."

"Selina will have lots of dreams, won't she?"

"Yes," I say, sparking the car into life.

Mandy thinks for a bit. "Is Selina coming now?"

"Yes," Myra says. "You're very sure it's a girl, aren't you?"

"Yes," Mandy replies, "because in the night they told me that another half a million years is starting. Have you still got my tooth?"

I say yes, I still have her tooth. It is still squeezed in my fist like a token of some miraculous covenant as I drive us to the hospital, because the baby is coming.