Kilburn High Road at five—the evening rush hour—is like a tinkling river of fireflies, each bicycle with its own wavering, quivering little light, all rattling and clicking as they make their way up towards Cricklewood or down towards London. The hated rickshaws take up too much space—they are getting more numerous each day. The infrequent buses get stranded at this hour, their train of patient, puffing horses easily sidestepped by human muscle.

Turning left on Brondesbury Road, I am left with my own faint cone of light on the black wet tarmac. Here and there I see candles and oil lamps at the windows, but they are self-contained bubbles of light that signal their presence and no more, none of them generous enough to help me on my way. I have a memory—probably false—of Brondesbury Road one Christmas, every window full of decorative little pinpoints of electricity like droplets of dew on the grass, all glowing with yellow warmth and abundance. In reality, even at the best of times only some of the windows would be lighted up, most by the cold radiance of television sets. It is probably the sodium glow of the streetlamps I remember—who would have thought I would ever miss it.

At least the night is mercifully warm. There have been nights in January when even the effort of cycling up from the City wasn't enough to warm me, and my sweat froze on me. March is probably going to be just as bad, if memory serves, but who knows?

I chain the bike on the side of the house, alongside Rebecca's and Richard's, fumbling with cold wet fingers in the darkness, praying that nobody will steal it, at least for a little while longer. I should take it up to the flat, but the stairs are too steep and too dark.

The cat is meowing from behind the door as I climb, her voice guiding me as much as my memory. One day I put my hand, supporting myself, on the long-dead light switch, and a pang of painful memory went through me. I suppose the naked bulb is still up there, but I can't see it right now, not even with the door open.

The cat meows and purrs, looking down at me from upstairs, but she never comes down to the entrance landing, although she must be able to see much better than me in the darkness. I find the matches in the dish by the door and quickly light the candle.

Ah, blessed light! In the yellow glow, my home is cozy and welcoming, and the cat's eyes are wide with anticipation.

I clamber upstairs, balancing the work bag and the grocery bag and the candle, puffing a little but far less than I used to when I had the Tube and the buses and my car to take me to the job. We are all so fit now, and so thin. The cold nights shivering under blankets that had been enough for central heating have made us all long for that nice wrapping of fat.

I put the milk in the icebox and set about cutting the meat for the cat, while she weaves around my ankles meowing in protest. She had been used to having food always at her disposal, nice dry food that never spoiled, never ended up stinking and covered in white maggots.

"Yes, yes, it's coming," I tell her. Talking to her seems to keep her quieter, or at least changes her indignant demands to chatty responses.

I try the tap, but again, there is no pressure in the pipes at this time of day for all of London, and Kilburn is some way up from the river. It will be another evening of pedaling to fill up the tank, later on. I'll have to go knock on Rebecca's and Richard's doors for their help.

At least I can use the dynamo to power the radio at nine o'clock instead of cranking that damn handle, I tell myself, trying to cheer up. It doesn't really work. I am so tired that I was ready to give up the half-hour transmission anyway.

And then it happens. All the lights come on. I later remember a noise, like a click, but that, too, is probably a false memory, as if something so portentous cannot happen in silence. A few seconds later, an incredibly sweet chord comes from the dining room, to surprise my ears—the computer!

I step back, the knife still in my hand, gleaming, every color in the kitchen jumping out at me, the light so strong, so fierce!

The forgotten displays are all blinking: the dusty microwave that I have long used as extra storage, too bulky to be thrown away; the oven clock; even the turquoise light of the radio comes on, but no stations are on air. There is only static.

The cat is still demanding her dinner, oblivious to the moment. I look in wonder at my hands, red from cutting the meat, and open the tap cautiously. There is water flowing out, dirty, brown water but water nonetheless. I put my hands under the icy flow, my heart beating so hard I can almost hear it.

I know it's useless, but I try the telephone all the same. The telephone I left connected from the last time we briefly had power, because I kept hoping. Back in the last days of electricity I had substituted the cordless with an old corded model, because the cordless would never have managed to hold its charge from one whiteup to the other.

I pick up the receiver and listen, but there is no tone. I sink down, in the sudden warm light of the sitting room, still in my work clothes and warm coat, and cry. Not even this miracle will give me back the voices of my distant family. If the phone had worked, who knows, I might have heard my mother's voice, or maybe heard from my father the news of her death—she was not in good health the last time I received a letter. And so I cry, partly in disappointment, partly in relief.

It is a measure of how long it has been that only then do I go to my computer and stare in wonderment at the neat, precise images and lettering on the dirty screen. It's like looking into a bright window that opens on the distant past, a past so sweet and golden that you think you must have imagined it, that even thinking about it hurts, like your childhood or your last being in love. I reach out, softly touch the warm, glowing screen. If I had paper, I could print out all the things I have lost, my writings and my diary and the letters of my friends, everything that my computer has been faithfully preserving in the long night. How would I choose? What to save first, before the lights go out again? But there is no paper; it was too precious and I have used it all up long ago. Even in my workplace, up there on the tenth floor where we painstakingly draw lines and charts and ink text in fine calligraphy, we now use heavy, yellowy paper, more suited for our gloved hands and scratchy pens than the slim blindingly white and incredibly abundant sheets we used to feed so unthinkingly into the printers.

There is an insistent knocking from below. I run downstairs, admiring the architecture of my stairwell for the first time since autumn, and open the door to Rebecca and her kid, both blond, both slightly dishevelled.

"You too?" she asks, breathless. The bare bulb is glowing over her head, giving her hair a golden shine that I haven't seen in so, so long.

"What happened?" I ask. Rebecca is better than me at learning what goes on. But she shakes her head.

Without needing to consult, we both walk out in the street, me still wrapped in my coat, her in her pullover. But I doubt that even without my coat I would be cold. I am shaking with emotion, shivering with something that I can't give a name to. Hope? Dread? Fear?

Everybody else is out. We look up and down the street, talk to each other. Young children are looking up at the streetlamps in wonder. They have never seen an electric light so big, so bright. Several have failed, more vulnerable than our indoor wiring to the elements. The cars, rusted, covered in dust, still manage a triumphant gleam, as if they had always known that this day would come.

Rebecca discusses with our neighbours on the left, the ones whose emergency beacon now shines white and glorious from the porch, if we should go down to Salusbury Road, where the police station is. If anybody has any news, any explanation, she says, it'll be the police.

"But they won't give it out," the wife says.

"It's the Chinese," the husband says, with the certainty of somebody who knows for sure, and for a moment I even believe him. It has to be something. It has to be something. It's been years since I have seen the gleam of electricity through a window, even down in Whitehall. It's been years since the last whiteup.

Somebody has a radio, and fiddles through different tonalities of static. People crowd around him, waiting. I wait too. I trust Auntie Beeb. Somebody will be cranking up the transmitters, surely. Somebody will come on air, with the unflappable tones of Radio Four, and tell us what is going on.

I look at the sky. For years I have seen only the stars, and the clouds when the moon would light them. Now the sky is radiant, lighted up with the shining of London, an orange glow.

Orange, and smoke. I shiver. There are fires burning, down westward.

"Look." Rebecca is pulling on my sleeve, pointing not towards the west and Salusbury Road, with its police station and gaggle of shops and possible information—but towards Kilburn High Road, the artery going towards the city, the street which once led all the way out to the M1 and Stanstead Airport and the North. There, at the end of the road, there is a light that is not fire and not streetlamps. A light and noise that are like nothing we've ever seen.

We walk, and then we run, all the way to the road. All of Brondesbury Road seems to be with us, flowing down like tributaries to the sea, flying towards the light alarmingly like moths. There is a plug of people in the intersection, and I lose Rebecca in the crowd. I slither urgently forward, sliding behind and through the crowd, until I am on the verge of the pavement and I see them marching down the road.

All around me is the throwback London, the bicycle, oil-lamp, icebox London, like one of those bad Victorian movies I used to so despise, and now so miss. In front of me, marching down the street, is a Hollywoodian dream of chrome and light and clicking mechanisms. In my crowded flat, still kept religiously in hopes of one day coming back to life, are stacks and stacks of DVDs, their bits silent, their dreams of huge space machines alive only in my memory. I cannot make sense of what I see. Our mouths open, we watch them coming down, enveloped in light, in perfect formation. Are they human? I can't tell.

I scream—because somebody has to—at the top of my lungs, in a road that is strangely quiet over the strange humming: "Who are you? WHO ARE YOU?"

One of them turns. He, or she, or it, comes towards me, with a smooth, mechanical movement. There is a shining light over the helmets they wear, so bright and white that it shatters all shadow. I try to see a face, to read something of what it is that came to us today, an intent, a disposition. I try to see if there is a face, human or not.

But we are no longer used to the light, and it blinds us, and I cannot see.