When I was living in our house I was woken constantly by the nightly passage of the nuclear train. I live on the train line still, but much further to the east. The train goes past as I write - the table wobbles and the windows vibrate. But these are the least of the effects of the nuclear train.

My strongest memory of Martha and Mary is of them playing together in the bath, fully clothed, a few nights before I left. 'I've got no arms, Dad,' Martha shrieked. 'I've got no arms, I can't get out.' I watched them and wondered: Should I just turn on the taps? Shut the door? what would happen then? Would I still feel Mary's gaze upon my face? Would I still see her eyes, even though her head was turned away?

A little later I thought: I worry about my health. Tonight I'm going to rob the health store. I have it all planned. I'll get Dmitri, with the long eyelashes and beautiful Roman nose, to help. He will be an asset if there are women or queers involved. Me - I'm too ugly. But I know that, I accept it. My beauty lies in my skill with appliances and in the fact that I know when to talk, when to keep silent.

Here's the plan. We'll disable the alarm with sodabread and stuff our loot into rafia bags weaved in hospitals by schizophrenics. We'll smoke yage and shoot anyone who gets in our way and trash the place. Dmitri can shit in the cashtill; it's more his thing than mine. Then we'll leave together for Docklands and hide from the law amongst the taxis, the battleships and the foam.

Rever lurked there already, haunting the railway sidings and the building site, his home a Portakabin half-hidden in the shadow of a satellite receiver dish. Rever is quite mad. He had a dog once but he lost it down one of the many holes that have been sunk in preparation for the piles. On clear days he still climbs the cranes and the gantries calling for it across this land which is sodden earth and filthy water and whole worlds of garbage in between. But I think what he really does is watch the wavelets in the docks, tracing back the numbers that heave and permutate beneath them to the tireless operations of the towers.

Rever was ill when we found him, suffering some kind of fever, so we gave him pills and half of the wheatgrass juice that we'd stolen from the shop. Dmitri drank the other half; he'd lost a lot of liquid during our escape. I took what tablets Rever didn't want - even though the house was far away I could still see Mary's stare everywhere I looked, and I thought that they might help.

The pills did their work and soon the days were like a set of steps leading down into the river. We spent our time, then as now, picking amongst the rubbish piles that punctuate the waterfront, each heap a lazy full stop on the useful life of consumables: polystyrene chips, motherboards, empty cans, sheets of polythene, baby carriages, the bones of seagulls and the carcasses of white goods. I would like to say that I found something poignant, like the juxtaposition of a child's doll and an umbrella, or a bundle of love letters lying in the bruised petals from a old bouquet, or even yet a hat, a pipe, the racing pages. But the garbage had no resonance with the past.

I complained at this to Rever, said that I missed my home, with its noise and smells and the six inches of subsidence that let the rats into the kitchen, and he told me how I was an idiot, that I had no right, that down here things were moving on and that I should be grateful for this horn of plenty that brought us objects freed from connotations. But I couldn't see how this was good enough and so I insisted that I worried for Martha, that I missed her, that she couldn't survive down here because she had no arms, until eventually Rever gave in and said he'd help me build her some - from turntables and the guts of several washing machines. I embarked upon this project with glee and felt not the slightest guilt in enlisting Rever's aid for several hours each day since every morning for weeks now he'd been forcing the rest of us to comb the area for his wretched dog, which he claimed beyond all reason was still alive and roaming through the earth beneath us, foraging for light and air and living off moles and worms.

Once the arms took shape, however, I became unable to think of anything else at all. I made excuses to stop participating in the search for the missing dog, and whole days went by without me exchanging a single word with Rever or Dmitri. Soon I was neglecting my work on the rubbish heaps, preferring to sit around all day with only the half-finished mechanisms for company, tinkering obsessively. My behaviour infuriated my companions, who decided not let me near the fire at night by way of punishment. But I couldn't see the point in salvage anymore. The detritus on the heaps had no connotations in the first place; to work with it at all I felt I had to be allowed to impose my own. Now even this had been denied me, and for the first time I began to regret the actions which had brought me here. Despite my efforts I didn't hear from Martha as she had promised and Mary's eyes still haunted me at night. Soon I began to lose heart even in the arms and soon they lay twitching in a pool of oil with no one to attend them. I feared the worst - that Martha and Mary had been implicated in the theft, taken in for questioning. I thought that any contact might be dangerous.

Again, it was Rever who came to my rescue. I think now that he had been watching me all along, monitoring my course, letting it run. Whether that's the case or not, at one point he took me aside and walked with me alone along a jetty.

'If you want to find them, why don't you search in there?' he said, indicating the cluster of towers that stood in the middle distance and dominated the skyline and turned the night from black to red. 'What's there that's got anything to do with me?' I asked. 'Don't you know?' 'No idea.' 'It's a conduit for all the information. The tallest building is a processor. Not long ago, there were many small operations, doing the job in their own fashion, dotted around the city. And then they built this. Most of the old ones have been replaced. Nearly all the information gets channelled through here now. That's why I came here. I wanted to experience the reorganisation of these flows.'

It was then that I realised that Rever was extremely wise, and that in spite of all his teachings I still had not realised quite how powerful the forces around me were. I looked at the buildings and I looked at the docks that had been let into the earth around them; I looked anywhere except at Rever's haggard face, pitted as it was with acne and the memories of knife fights. I watched a frigate manoeuvring its stern out from the pier. Looking at its pretty guns and helipads I dreamt for a moment of sonar and radar interfering with my body. I thought of a room filled with bronzes. It was a place I had never been. Later, I did what Rever said, and visited the building.

I'm told - by Rever, of course - that the nuclear train comes down here to unload. I think I saw it as I picked my way across the scrub and mud flats towards the building. Black as night and twice as long. I thought: This is the only connection I have left with home. I thought of home, my old home, the home before the cabin I have now. You can tell the nuclear train by its weight. Most trains, the passenger trains, the goods trains, they rattle the windows and made liquids oscillate in cups. But the deep vibration of the nuclear train makes plaster shift across ceilings, settles whole streets into their foundations, disturbs cell growth deep inside the womb. Only a month ago I filled the hole out front where the rats danced, drunk with isotopes, but already there is another small crater - you can see it from our bathroom. I tried to get the people who live next door to help me out, but they didn't understand and now they're shunning me. So I went to see the council but they were no use either. Everything round here is falling apart, I told them. They said that no one wants to know.

I told Mary about the rats that danced, the council and the neighbours, the craters and the train. These were the everyday; with these thing there was not a problem. But when I told her about her eyes she left the room and looked at me. Martha sat in the corner, playing with her wooden train. A vase fell off the shelf, which I caught just in time. But I couldn't catch the vase and stop the train, which went round and round and round in circles with no one pushing it. I yelled at Mary to come back here now see and so she did, and that was when I told her about the things Martha was learning how to do with the inside of her head.

'What sort of things?' Mary asked me. She sounded more worried than ever. 'Martha, show her the vase,' I said. 'What sort of things?' 'Martha!' I shouted. 'Show her the train!' Martha was frightened of me and so she demonstated, rattling a glass until it tipped over on the table and rolled onto the floor. She was sitting by the sink, which is not near the table, so everything was obvious. The glass smashed and Mary screamed and rushed over to the window. 'There are no trains now,' I said, 'it's no good looking for them.' 'No trains,' Martha echoed. 'Shut up!' I said. Mary wept. 'Jimmy,' she wanted to know, 'why are you doing this to us?'. 'I'm not doing anything,' I said, and pointing to my daughter cried: 'It's her.'

I left the room and paced the hallway, more and more frustrated with the challenge all this posed. I tried asking Mary if this was a recent development but she could not - or would not - remember. In the end I became angry and had to vent my rage. 'I feel sick, I feel so sick sick sick!' I yelled.

And then I hit the girls and kicked the wall. After that, I developed denial. I told Mary I thought it was the nuclear train, that it had done something to Martha and now it was doing something worse to me. I told her that something would have to be done, whatever the neighbours and the council had to say. And she told me yes, she agreed, but I could tell by the look in her eyes when I slept that she knew I would be going away. I didn't want to, but I had to. I told her this, then I made her promise to follow and bring Martha too and we'd start a new life, away from here, a new life somewhere else. But the truth was we'd both made these promises too many times already.

So I robbed the health store with Dmitri and we came down here to hide. And Martha and Mary never followed, even though I built the arms and came to understand the nuclear train in the end. I did look for them in the building like Rever suggested but I found nothing there but pictures and stories, nothing that made any sense. But by then it was okay, I wasn't so bothered, because I'd come to understand that the way it had been before was not the way things worked and that all these things had come to me not I to them. And in those last days in that building, in the run-up to the moment when my access was finally denied, I knew from my position on the eighteenth floor exactly where Rever was at all times, and the position of his dog, too, deep there beneath us, in the wormholes of the earth, and this made it all okay.

And so I returned to the salvage with the others, and I worked at it this time without difficulty. And I knew the objects that I needed when I saw them, even though they possessed neither past nor connotation. And I no longer miss Martha and Mary because I am always with them, via the arms that I built and the nightly passage of the nuclear train. And in the evenings, when it's cold, Rever and Dmitri they let me come and sit beside their fire.

The Nuclear Train will be included in the short story collection, Soft Apocalypse