I walk round the cul-de-sac until I’ve done my steps.

All the houses look the same around here: sixties bungalows, two bay windows, a front door slap-bang in the middle and roofs that go up forever, like a face with a huge forehead looming over a frown or a sneer. Jude calls it the Suburban Psychotic style.

The bungalows disapprove of us, dismissing any signs of frivolity, sweeping away our personal touches. Not that we don’t try. Next door put stickers of puppies on their wheelie bins. They hovered serenely, a foot off the floor, tongues lolling, smiling their puppy-dog smiles before they faded and peeled away. Now all that’s left is a disembodied puppy eye and the tip of a puppy tail. The family over the road had window boxes for a while, but nothing grew in them and now they’re just rotting bits of wood.

The same thing happened when we moved in. Jude bought a little concrete Buddha from the garden centre. She painted his robes metallic blue with some paint we found in the garage and his face orange using nail varnish. He looked like a cover for an electronica album. We put him by the front door, but every time I looked for him, he was obscured by weeds and then, eventually, he just vanished.

I feel like I’m disappearing too, growing transparent, emptying out. Sometimes I wonder if I used up all my personality when I was younger, burnt it away in pubs and clubs, laughing and drinking.

I check my phone. Another two thousand steps to do.

From the darkness of the street, I can see my neighbours illuminated in their kitchens and living rooms, like characters in an exceptionally dull soap opera. I wonder if everyone feels this same washed-out emptiness or if they’re happy heating up ready meals, scrolling through social media, the same routine day in, day out. Our standard-definition lives.

My phone vibrates and a miniature firework display plays on the screen.

‘Congratulations, Samantha!’

Ten thousand steps.

I double check to make sure that it’s logged properly in the app. On the screen there’s a map of my walk, a tight blue loop superimposed on the cul-de-sac.

I put the TV on and watch rich women in the US talk about their problems. I eat a calorie-controlled ready meal with a bag of baby-leaf salad and drink a litre of water. I watch a programme about the decline of insects and another about modern slavery and then turn the volume down and just let the light from the TV wash over me.

When I get ready for bed, I notice something dark and angular on the wall, behind the curtain. A black parallelogram of skin and bone and fur – a bat. She’s fast asleep. Her tiny claws look like they are grasping the flower stems that blossom on the wallpaper. Her wings are tucked underneath her dark velvet body, the bones of her arms visible through her skin. Her small face peers down at the tangle of T-shirts, bras and knickers kicked under the windowsill. She’s beautiful, ebony black, wholesome as a newborn. I open the window as wide as I can and hope that she makes it out safely in the night. I take a picture of her and I send it to Jude. I see it’s delivered and watch the screen for a while to see if she reads the message.

Navigating the frozen food aisle has been getting much worse over the last couple of months. Today it floors me. When I turn the corner from World Food, I know something is seriously wrong. It feels like all the air has been emptied out of the supermarket, like someone has put a plastic bag over my head and tied it tight around my neck. A heavy darkness pools above me, settles on my shoulders and pushes me to the floor. Panic gives way to light-headed bliss and the world fades blood-red to black.

When I come round one of the shelf stackers is offering me a bottle of water. She sits beside me for a few minutes to make sure I’m alright. The hard light of the supermarket flickers just outside my range of perception. I can feel the heat of her where she leans against me. I’ve had fainting fits before, I tell her. Anxiety, I tell her, and I smile weakly. She helps me get up. I keep hold of her hand for a moment longer than I need to, happy to feel her skin against mine even though I worry about exposure.

I’m shaky and my knees feel weak, but I know I should shop while I still can; the supermarket might be even worse next time round. I fill the trolley with tinned vegetables, packets of noodles, dried crackers, jars of meat paste – everything individually wrapped, self-contained, sealed. I try to avoid touching the conveyor belt at checkout. I try not to breathe the same air as the woman with age spots spreading over her skin.

When I arrive home, I get into the shower and scrub my skin until my elbows and knees and knuckles are raw. The water spills over my body in pale pink ribbons that swirl round my feet. My fingers feel for early signs of infection, lumps, swelling, bruising, ulcers, any softening or corruption of the flesh. Nothing.

I get clean gym kit from the dryer and head outside to do my steps.

The supermarket thing has happened before. Well, something like the supermarket thing. I need to work out what it is before it starts to take over. Last time it was pills. Jude told me one of her pupils had been rushed into hospital because she’d mistaken sleeping tablets for sweets. I began to worry that I would accidentally kill a child with my drugs. I cleaned my handbag out and locked all the bottles and blister packs in the bathroom cabinet. I began to worry that I’d missed some. I turned my handbag inside out, checked all the pockets, ran my fingers along the seams to make sure none had somehow got into the fabric of the bag. It didn’t help, I imagined pills falling out when I went shopping or caught the bus into town. Once I put my handbag down in Jude’s classroom when I went to collect her and had a panic attack. We had to go in early and clean the room. I had to take all the art supplies off the shelves, flick through every page of every book and empty each locker before I could leave. Even then I imagined pills buried in the plasticine or the sandbox. When I got home, I tied the bag into a bin liner and threw it into the loft. It felt dangerous, spiky, filled with sharp metal, like a nail-bomb.

Seven thousand five hundred steps.

It got worse. I began to worry that the drugs were falling out of the bathroom cabinet and getting stuck to the bottom of our feet. I’d make Jude stand on the bed and show me between her toes before she put her shoes on. I’d check her again in the hallway just before she left the house making sure that there were none stuck on the soles of her shoes. I burned our sandals because I thought there were too many places for the pills to lodge. I stopped sleeping with Jude, worried that the pills stuck to my body would be transferred to her. At first, I just slept on top of the duvet, then I bought a sleeping bag and used that, eventually I slept in the spare room.

The fireworks go off. I check the walk is recorded.

For dinner I open a bag of salad, cut six cherry tomatoes in half and empty a tin of tuna onto a plate. I watch a documentary about Romanian street kids who sniff a brand of car paint called Autolac. Then I watch the news. There has been an outbreak of an unnamed disease on local farms. The chicken farmers slaughter and burn thousands of birds, through the flames you can see the feet blacken and contract as though they are trying to grasp something. I wonder if I will be able to smell the burning carcasses. I can’t see any smoke from the kitchen window, just endless lines of polytunnels, a plastic-wrapped landscape.

There are more bats in the bedroom. Three now. They hang upside down, their little toes disappearing into a dark crack in the plaster. I lay on the bed with my phone, trying to identify them. They don’t look like any of the bats on the conservation website, their faces are longer, more elegant, like a fox. They’re bigger too, about twenty-five or thirty centimetres, I think. They might be fruit bats, which seems improbable for Yorkshire, but not impossible I suppose. The summers have been getting warmer so maybe all sorts of animals can live here now? Maybe they arrived in a crate of bananas? I once heard about a woman who found a tarantula in the local Tesco, it had crawled over to the clothes section and was tucked between the T-shirts.

I’m finding it harder to do my steps outside. I walk up to the front door and put my hand on the door handle, but I can’t bring myself to open it. There’s something grainy and dark outside that I can’t face, like a migraine or a horror movie, like a documentary. I do my breathing exercises. Breathe in, one, two, three, four, five. Hold, one, two, three, four, five, six, seven. Out, one, two, three, four, five, six. I walk back to the kitchen and have a glass of water. Finally, I force myself outside. For the first few minutes I can feel my pulse racing. Bile rises in my throat, the bitterness creeps along the edges of my tongue and it makes me want to gag. I focus on the sensation of my foot hitting the pavement – heel-toe, heel-toe, heel-toe – and gradually the rhythm helps me feel calmer.

When we got together, we talked about having kids all the time. That expansive moment in a relationship when everything seems possible. Jude would carry one and I would carry the other. We would use the same donor so that the kids were related. We would be bound together by love and blood. I could imagine Jude becoming fat, full of life, her skin plump and pink but I could never imagine a baby growing inside me. Jude would teach them to paint and swim and bake, to be alive in every moment. I tried to think what I could teach them, but I couldn’t think of anything.

The fireworks go off.

I’ve spent most of the last week in bed with my phone, watching YouTube, refreshing Facebook, deleting the endless offers that appear in my inbox. I’m worried about Jude; I haven’t heard from her.

The only thing that keeps me going is the bats. There are about twenty now and they’re giving birth. The scrawny pups cling to their mothers and squirm under their wings. I don’t know how they can fly when they’re carrying their young. I lay quietly on the bed and watch, my mind full of dark flight.

I can’t go outside anymore. The cul-de-sac is too dangerous.

I have pushed the furniture in the living room against the wall so I can do my steps inside. It worked well for a few days, but whatever was in the supermarket and the cul-de-sac seems to have followed me inside. I’m not sure how much longer I can keep up my routine.

Today is really bad. Horrific scenes spool through my brain like videos on auto-play while I do my steps. As one scene finishes another starts, getting more and more extreme, demanding my attention.

Coral reefs fade from scarlet and turquoise to bone grey. Wildfires flow down the East Coast of America like lava down a volcano, burning everything in their wake. A gay man with a sign around his neck is marched to the edge of a rooftop and kicked off the edge, the crowd below cheer. A vet weeps as she pulls plastic bags from the stomach of a dead whale. Sea water rises. Epidemics rage. Planes crash into buildings. Cars ram protesters. Government agents smear poison on door handles. A woman is beheaded by three militants. Cows are fed with infected spinal cord. Bird flu. Swine flu. MERS. SARS. The sixth planet-wide extinction event. The growing gap between rich and poor. Vigilantes on the streets. Corrective rape. Sweatshop labour. Colony collapse disorder. Erosion. Beirut. Chechnya. Afghanistan. The opioid epidemic. The obesity epidemic. The loneliness epidemic. Alcoholism. Fentanyl. Food banks. Paedophile rings. Troll farms. Slums. Electrodes applied to genitals. Chickens debeaked and plucked while still alive. Political opponents publicly executed with anti-aircraft missiles. Drug trafficking. Radicalisation. Micro plastics. Black men shot by the police. Young women shot by incels. Active shooter exercises in schools. Economies kept afloat by arms deals. A suicide bomber on the bus. Mass surveillance. Poisoned ampoules inserted under the skin. The rise of the stateless. The rise of Nazis. The rise of C02. Riots. Looting. Flooding. A dead child washed up on the shore.

Fireworks.

Ten thousand steps.

I can’t carry on like this.

I’m sick as a dog. I have a high fever and can barely move. I sleep most of the day and when I wake it takes me all my energy to make it to the kitchen or the bathroom. I bring all the remaining food from the supermarket and stash it under the bed. There is almost nothing left. I fill bottles and pans with water, so I don’t have to leave the room. I have never felt this ill before. I fall asleep to the sound of wingbeats.

The bats whisper to me when it’s dark. They tell me that the baby bats can almost fly, that it’s time to teach them how to feed and roost on their own. They worry about me. The darkest and most beautiful sits on my pillow and tells me stories as I drift in and out of sleep. She tells me stories about dancing among the stars with her lover and the welcome shade of the mango grove in the heat of summer.

‘What’s your name?’ I ask.

She clicks and beats her wings. I furrow my brow and she clicks and beats her wings again.

‘I don’t think humans can say our names,’ she says. ‘What’s your name?’

‘Samantha,’ I say, ‘Sam.’

‘S-am,’ she says, ‘Saam.’

‘Close,’ I say and smile at her encouragingly. ‘Would you like a human name?’

She nods.

‘Lilith,’ I say, ‘you should be called Lilith.’

Lilith croons bat lullabies in my ear and rubs her warm fur on my cheek. Her baby squeaks and sticks out her tongue.

The next day I eat the last of the food and try to get up. Lilith opens her eyes and sways gently above me.

‘What are you doing?’ she says.

‘I have to walk ten thousand steps,’ I say.

‘You’re too ill,’ she says.

‘I can’t miss a day,’ I say.

She fixes me with a stare and I sink back onto the bed.

‘See,’ she says, ‘you can barely stand up.’

I know she’s right, my face burns and I’m so tired I feel like I might black out, but I can’t bear the thought of interrupting my streak. I’ve walked ten thousand steps a day for almost two years. If I stop now, I don’t know what will happen. The consequences terrify me.

‘You must stop walking in circles,’ she says, and then after a few seconds silence, ‘you need to get ready for your journey.’

‘What journey?’ I ask.

She doesn’t answer, just closes her eyes for a few seconds then says, ‘we’ll bring you food.’

I tell myself that I’ll do my steps later and I fall asleep immediately.

When I wake up the bats have laid out food on the windowsill – cherries, strawberries, pink prawn-shaped sweets, three bees and a bluebottle. I fall onto the floor and crawl over to sit in the chair by the window. I have to rest for a few minutes after the exertion. I brush the insects onto a paperback and tip them out of the window. I pick up a strawberry and eat it slowly. The sweetness fills my mouth and spills down my throat. It has been a long-time since I was looked after. I feel guilty about not doing my steps, but I am so ill, I can only just manage to eat.

The electricity has gone off. All the houses in the cul-de-sac are dark and the street lamps have stopped working. My phone still has a charge, but I can’t load anything. I turn it off and on, but it doesn’t help.

The bats take care of me. When I tell them I don’t like insects, they smile at each other like parents indulging a fussy eater. Mostly they bring me pick ’n’ mix and fruit: greengages, aniseeds, fizzy cola bottles, apricots, dates, watermelon sours, lychees, liquorice coins, plums. I have no idea where they come from or how it is possible for all this fruit to be ripe at the same time. For some reason there are always feathers mixed in with the food, short brown chicken feathers that I carefully pick out and set aside. They’re getting better at understanding what I like. There are no more insects, but they try other things: cold chips, half eaten sandwiches, a bit of wafer from an ice-cream cone. I politely refuse most of these offerings, until I see a sachet of brown sauce that I tear open and empty into my mouth, an odd, sweet spiciness that tastes peculiar after my diet of fruit and sweets. I squeeze what’s left onto the side of my hand and hold it out for Lilith to try. Her tongue is dry and rough like a cat’s. She screws her face up and I smile for the first time in weeks.

My fever lasts for days. I lose track of where I am and how I got here. Sometimes I think I can hear Jude banging on the door. Sometimes I think I can hear people talking about me in the next room. I wake up in the middle of the night all alone and replay the scene in the supermarket over and over. I’m beginning to think I have caused something terrible to happen.

I remember my knees buckling and my head sliding down the glass. I remember clutching the handle of the freezer, the door sliding open as I slipped to the floor, coming to rest on the dirty lino. Through the open freezer door, I saw polystyrene cartons of chicken wings, the flesh sallow, skin slack like the hands of an old man, the ball of bone wet and white and spotted with blood. I remember the floor faltering and rolling like a boat in a storm. Tiny motes floating in front of me: petrol-blue viruses and synthetic-pink bacteria spinning in the air, doubling, tripling, quadrupling, infecting everything: tracking along the capillaries and veins of the chicken, blooming in the fat, spoiling the muscle, corrupting the bone.

The darkness flooded over me and pushed me further down. Down, down, down. Down through the lino, down through the concrete, down through the contaminated earth. I watched busy mothers above me picking up infected packets of wings and drumsticks and breasts. I saw the bloody water seeping through the plastic-wrap, beading on the bottom corner of the tray and then swelling until a droplet grew so heavy it splashed on the floor. Drip. Another droplet splashed near the baby food. Drip. Down the dairy aisle. Drip. Through the carpark. Drip. On the bus or in the car. Drip. Drip. The front step. Drip. The hallway. Drip. The kitchen counter. Drip. Trails of diseased blood radiating outwards from the freezer, until the whole town is infected.

The fever breaks; the bats have vanished.

For the first time in days, I make it to the kitchen. I lean against the sink and drink glass after glass of water. Late afternoon sun falls on my back and casts a sharp shadow on the floor in front of me. I study the outline scared and exhilarated by what I might see but there has been no obvious transformation.

My phone only has one percent battery left. I plug it in, nothing happens. I flip the kitchen light on and off, the power must still be out. I try to message Jude, but it isn’t delivered. I open my walking app and a transparent blue dot floats in the middle of the screen to show me where I am, but none of the roads will load. I pinch the screen to try and see more of the local area, nothing appears, just an illuminated blankness speckled with dead pixels. I stare at the blue dot on the screen until the phone shuts down.

I pack my rucksack in the last of the light. I walk round my house for a final time to say goodbye. I put on my walking boots and head outside. Underneath the bedroom window are two dead bees and a dead bluebottle. I poke one of the bees gently with my toe and a leg falls off.

There are no lights on in the houses, the windows are glossy and black like pupils dilated in fear or ecstasy. I walk out of the cul-de-sac and turn onto the main road. None of the streetlamps are on. I look for the comforting sodium glow over the centre of the town but it’s not there. I follow the pavement out of town until I reach the recycling plant. I cut along a concrete ditch to the field behind. My eyes adjust to the darkness. The faint light of the Milky Way is smeared above me. I can just make out the horizon, where the dark sky reaches down to the curvature of the earth. I walk across the field until I can no longer see any of the houses. Out here the landscape is empty; there are no trees, no hedges, no distinguishing features just the rawness of the earth and the crystal-cold air – a vast austerity that calms my endlessly scrolling mind.

I wish I could take to the air. I wish I could feel the dark volumes of the night pulse against my wings. But I cannot.

I turn to the north. I will avoid the roads, the villages and towns. I will forage for food. I will wash away the stink of my humanity in gravel-bottomed streams. I will live in the woods.

It is getting colder.

I put one foot in front of the other.

I do not count my steps.

Image © Caomai