My wife Khadija is the logical one, anyone could tell you that. When Khadija and I occasionally share the number 4 bus in the morning she has her head down to work at a crossword the whole way, methodically filling in the blanks, while I merely stare at my hands or at the strangers around us. There are strangers everywhere here and I often think of London as a collection of distinct islands of islands within islands. She, on the other hand, is a firm believer in ‘making friends’ and is ever-mindful of improving her English despite the fact that it is now better than our British-born neighbours’. Khadija also deals with the cold better than I do and slips extra layers into my bag on days such as this one, distrustful of my ability to cope. It is often late when I get home and I still forget how far the temperature drops here in the evening. It has been five years since we moved to London from Patna.

My wife cleans for the Church of England school in Archway where our daughter Tiranum attends nursery. I clean at the Whittington hospital, or ‘the Whit’ as the locals call it. That is what you get for studying Urdu literature in an ex-colony. My mind wanders constantly as I clean and if I’m not careful I’ll end up being sacked like the West Indian man here last week. We work for a private contractor and they are very strict with us – not so strict with how well we do our jobs, but speed is essential. So I must focus. On dirt. If I allow myself to slip into a trance-like state it becomes easier to do this, which is not so difficult to achieve when I’m tired.

I sweep the floor under and around a female patient’s bed, pulling the dust towards me. I have to move it to the left to get to a section I can’t get to but I have to be careful as she is plugged into machines that are keeping her alive. The wires and the machines are her rope and anchor, for if they come away she will drift out to sea and who knows how long it would take for someone to come. A screen has a green wave flowing across it that shows how her heart beats. Her sister sits in a brown plastic chair fast sleep, chin to chest.

I know only a little of this woman’s story: she is twenty-six and slipped in her own home after a few drinks, smashing the side of her head against the fireplace. She lives alone, so it was a while before she was discovered. If I did something like this, how long would it take for my family to know? Usually my wife and I have shifts that are hours apart.

There’s a plaster, the size you’d use for a cut finger, in the dust – stuck to itself, folded over and black at the edges. I notice even though I’m ten minutes from the end of my shift and most days I rush the last ward to finish on time. Khadija will be home by now, getting Tiranum ready for her evening bath. I think of her as I move the brush forwards and back.

Tiranum means melody. She has started to sing songs that she picks up from the radio. When I was off sick a couple of weeks back, I sung along with her as I fed her mashed potato and fish-fingers for lunch. She had begged me for ‘English food, Papa! English food!’ which means the cheap and easy food we keep in the freezer. I know some of the songs she likes from the hospital radio station that the patients listen to. But this woman, surely, cannot hear the songs from where she is. I reach over and switch her radio off.

The floor around the bed is a mixture of dark beige and light grey – beige in the middle and grey at the far edge where the floor meets the wall. I don’t have enough time to do the edges properly and I don’t get paid enough, but I clean the edges for this woman. I couldn’t tell you why.

I bend over to pick up the dirt and empty it all into a yellow bin liner. I’m so tired I can’t walk properly, my feet half-dragging on the ground – a noisy way of moving but no one notices. I’m invisible in this job and my shift is over.

I reach into my pocket to feel for a lighter and hear a sharp, high pitched bleep behind me. I’m near the staff room, near the automatic doors that lead into the night. I look back. Things begin to slow down and I am not sure of where I am.

I run to her. I almost slip as I’ve turned too fast and this part of the floor is still dusty, my own fault. The patient’s sister is screaming, holding the woman’s hand and shaking it as though it is time to go home now, it really is time to wake up. A nightmare is all that this is. Dr Maynard and a nurse are running towards us. I think it must be over for her and I know I’m right because you can tell by the faces: locked-in, rock-like, tired.

They call for the electrical equipment used to bring the heart back. I hear myself whisper, ‘She’s drowning.’ Dr Maynard is shaking his head, the way they do on the TV, but on the television they don’t catch the true darkness, or the weight, of moments like these. He smooths his forehead with his hand, rubs it with the tips of his fingers and closes his eyes.

The patient’s face looks the same: pale with dark hair curling at the neck. I don’t know the colour of her eyes. I want to go to her but I can’t. I am no longer of sure of who I am or of whether I am here at all. I float above the scene like a curl of dissipating smoke and it is an immense relief to be finally so weightless, until I start to sink once more. And I keep sinking until I am deep under water and there’s a ringing in my ears like an alarm. The patient is with me, pulling me down with her while I’m trying to bring her back by anything I can – her hair, her nightdress, her blue-white hands.

I open my eyes. I’m on the floor, looking up at Dr Maynard’s face.

‘How are you feeling?’ he asks.

The nurse says, ‘We should call his wife.’

I think of giving them my home number but allow that thought to drift.

The doctor says again, ‘How are you feeling?’ and I say, ‘Okay.’

He puts his arm under my back as I try to lift myself up and he helps me sit on the ground. I look at the bed. She has a sheet pulled over her face.

‘What was her name?’ I ask.

‘Yasmin,’ says she nurse.

The patient’s sister sits on her plastic chair and looks across at me with pink eyes. I look away. The doctor helps me to my feet and puts a glass of water into my hand. It is very cold.

‘Jasmine,’ I say aloud. ‘Yasmin is Urdu for jasmine. In my country, in the house where I grew up, the tiny white flowers grew all over the gate and hung over the fences in the courtyard. I could smell them through the open window as I fell asleep and I could even tell the time of night by the intensity of their scent. Sometimes when I sleep, I dream of going home and those nights are the best nights I have spent in this country.’

A porter wheels the body away while the doctor fills out a form. Someone somewhere is crying. I get up off the floor and start to walk in the direction of the staff room. The nurse wants to check my temperature but I gesture with my hands that this is not necessary.

I pause in front of the glass doors, which glide open silently, and watch the rain fall. It’s pouring down and thunder shakes the sky. Cars pass, a stream of white lights from the front, a stream of red from the back.

When I get back, Tiranum will be asleep and Khadija will be waiting for me in front of the gas fire. I’ll say the buses were held up because of an accident, because there is nothing else to say. Another island claimed by the sea. The same will occur tomorrow, no doubt, and the day after that one.