By leaving work late I miss the worst of the crush on the Tube. When I first moved here I made the mistake of fighting my way through the rush hour, and every day the panic got worse. There were too many faces to scan, too many bodies pressing in from all sides. There were too many hiding places, and not enough room for me to run. So I leave work late, which makes up for me getting in late. I keep moving, up and down stairs, along the platform, until the last possible moment and the doors are just closing, before I jump on the train. That way I know for sure who I’m travelling with.

Tonight I took a while to decide which way to go home. Every day I take different routes on the Tube, getting off a stop later or a stop earlier, walking a mile or so, then onto a bus, or back onto the Tube.

Usually I walk the last mile, taking different roads. It’s been two years since I moved here from Lancaster, and already I know the London Transport system as well as a native. It takes a long time and it wears me out, but it’s not as though I have to rush home. And it’s safer.

Once I got off the bus at Steward Gardens my walk home was punctuated by fireworks, the smell of them sour in the cold, damp air. I walked across the High Street, skirting the edge of the park. Doubled back down Lorimer Road. Through the alleyway – I hate the alleyway, but at least it’s well lit – and back behind the garages. I checked over the wall – the light was on in my dining room, the curtains half-closed. I counted the sixteen panes, eight on each door, which showed up as yellow rectangles, with neat edges where the curtains fell dead straight on either side. No extra bits of light showed through. No one had touched the curtains while I’d been away from the flat. I repeated this over and over again as I carried on walking. The flat is safe, nobody has been in there.

At the end of the alleyway, a sharp turn left and I was nearly home – Talbot Street. I resisted the urge to walk to the end of the road at least once before turning back; tonight I managed to get inside at the first attempt. I looked back while turning the key, which had been held ready in my hand since I got off the bus. The front door locked behind me. I felt around the edges of the door, checking it was flush against the doorframe, careful not to miss any bump which might indicate that the door wasn’t properly shut. I checked it six times, counting each time: one, two, three, four, five, six. I turned the doorknob, six times.

Right on cue, Mrs Mackenzie opened the door of the downstairs flat, Flat 1.

‘Coo-ee, Cathy! How are you?’

‘I’m fine, thanks,’ I said, giving her my best smile. ‘You?’

She nodded and regarded me, her head on one side, for a moment as she usually does and then went back inside. I could hear her television turned up to full volume the way it always is. The evening news. She does this every evening. She’s never once asked me what I’m doing.

I went back to the checking, wondering if she does it on purpose, to interrupt me, knowing I’ll have to start again from scratch. I’m alright as long as I don’t get stuck. Sometimes I do. So – the doorframe, the doorknob – do it properly, Cathy. Don’t fuck it up or we’ll be here all bloody night.

At last I finished checking the front door. Then up the stairs. Checked to the top of the staircase. Listened to the stillness in the house, the noise of a siren a few streets away, the television on in the flat downstairs. More fireworks, going off a long way away. A scream from somewhere out in the street made me catch my breath, but then soon after a man’s voice, a female laughing, reproachful.

I unlocked my front door, looked behind me at the staircase again, then took one step inside, closed the door, locked it. Bolt at the bottom, chain in the middle, deadlock at the top. Listened at the door. Nothing at all from the other side. Looked through the peephole. Nobody there; just the stairs, the landing, the light overhead. I ran my fingers around the doorframe, turned the door handle six times one way, six times the other way. One, two, three, four, five, six. The bolts held the door shut. I turned the Yale lock six times. I slid each bolt six times and back again, each time turning the doorknob six times. When I’d done all that, I could start on the rest of the flat.

The first thing I did was to check all the windows, and close the curtains, going round the flat in the same order. First the front window onto the street. All the locks secure. I ran my fingers around the windowframe. Then I could close the curtains tight against the darkness outside. From the street, nobody can see me unless I stand close up against the glass. I checked the edges of the curtains in case I could see part of the window. Then I moved over to the balcony, the double doors. In the summer I look out over the garden, checking the perimeter wall, but at this time of year there was only darkness outside. I checked the deadbolts on the balcony doors, felt all the way around the edge, turned the handle six times. The lock held true, the handle rattled loosely. Then I closed the heavy lined curtains against the blackness.

The kitchen – the windows in here don’t open, but I checked them anyway. The blind came down. I stood in front of the drawer for several minutes, picturing what the contents looked like. When I pulled it open, I looked at the tray – the forks on the left, the knives in the middle, the spoons on the right. I closed the drawer, then I opened it again to make sure. Knives definitely in the middle, forks on the left, spoons on the right. How did I know? Maybe I did something wrong. I opened the drawer again, to check. This time it was all right.

Then the bathroom – the window is high up and frosted, and again this one doesn’t open, but I stood on the toilet lid and checked the edges nevertheless, ensuring it was closed tightly, then I pulled down the blinds. Through to my bedroom. Big windows in here which looked out onto the back garden, but the curtains were closed already as I left them before work this morning. The room was in darkness. I plucked up my courage and opened the curtains, checking the wide sash windows. I had fitted extra locks to this window when I moved in, and I checked each one, turning and re-turning the keys six times so that I knew they were secure. Then I closed the curtains, pulling them right across on each side so that there wasn’t a fragment of dark window showing. Then I turned on the light beside the bed. For a moment I sat on the edge of the bed, breathing deeply, trying to calm the rising panic. At 7.30pm there was a programme I wanted to watch. The bedside clock said that the time was 7.27pm. I wanted to go and watch television. But the panic was still there, despite reasoning with myself, despite telling myself that I’d done it all, I’d checked everything, there was nothing to worry about, the flat was secure, I was safe, I was home safe for another day.

My heart was still pounding.

With a sigh, I got up from my bed and crossed to the front door, to start it all over again.

This cannot continue. It’s been more than three years. It has to stop, it has to stop.

This time I went through the whole process of checking the door twelve times before I moved on to the front window.