Five Days Before Dark

The scratching came again, somewhere in the darkness above our heads. I pressed my palm against Lucy's shoulder blade. Two quick taps, the signal we had practised until she could obey it in her sleep. She went still beside me.

Her breathing was so shallow that I had to watch her chest to make sure she was getting any air. Nine years old, and she had learnt to turn herself into a statue. No child should have to know how to do that.

The tunnel smelt of rust and standing water. Wet concrete. Something else underneath that I did not want to think about too closely.

We had been down here in Glasgow's buried network for nearly four months. The Subway tunnels, disused railway works and maintenance passages all bled into one another beneath the city, including connections that were not marked on any plan I had ever seen.

Long enough that I had stopped tracking the days properly. Long enough that darkness felt normal. Long enough that the weight of Glasgow pressing down through layers of street, soil and forgotten infrastructure no longer tightened my chest.

The scratching stopped.

I counted to sixty in my head, my hand still on Lucy's back. Her jacket was damp beneath my fingers. Everything stayed damp down here. The cold seeped into your bones and took up residence.

At forty-three, the scratching began again. A different position this time. Farther east, perhaps near Buchanan Street station.

They were moving in a pattern. Searching through the overhead ducts and across the concrete. The sleepless did not give up once they had caught the scent of something. I had learnt that the hard way.

The blackout had begun on 20 August 2018 at 20:43 BST. Nearly four months ago. In the first few days, when we still believed the electricity might return, people called it the blackout event. We still had words for things then. We still thought words meant we understood them.

The entire grid had failed. Not only Glasgow, according to the battery radios before they died. Reports spoke of failure across Great Britain, with fragments suggesting disruption farther afield. No one really knew.

We thought darkness was the problem. Thought we only had to stay calm, conserve what we had and wait for the council, the emergency services, the Cabinet Office or the British Army to put things right.

The darkness was only the beginning.

Something about the blackout changed people. The ones who did not sleep. The ones who stayed awake through that first night, and the next, and the next, trying to keep watch and remain alert. Trying to protect their families, their homes or whatever the hell they still thought mattered.

After seventy-two hours without sleep, they began to change. Their eyes went first. The pupils opened wide to catch every scrap of light, then developed a reflective quality, like a cat's eyes caught in headlamps.

Tapetum lucidum. That was the comparison that came to me, remembered from some nature documentary years earlier. I did not know whether that was what had truly grown inside them. I only knew I had never expected to see that cold reflection in a human face.

After that they stopped needing sleep entirely. Just stopped. Their bodies carried on moving, but deteriorated in other ways.

Their skin turned grey and papery. Their movements became jerky and uncoordinated at first, then smoothed into something too precise. Predatory.

And their minds. Christ, their minds sharpened into something that was no longer human. They organised. They hunted in packs.

They divided the city into territories and defended them with a single-minded focus that made my skin crawl.

The sleepless. That was what we called them now, those of us still hiding in the gaps between their hunting grounds.

Lucy shifted her weight slightly. Her hand found mine in the darkness, her fingers cold and small. I squeezed twice.

We are all right. We are safe.

I did not know whether either was true. But that is what fathers say.

The scratching stopped again. I waited, counting, listening to water dripping somewhere deeper in the tunnels. My eyes had adjusted enough to distinguish shapes: the curved tunnel wall, the rails long silent, the darker mouth of a maintenance opening about six metres to our left.

We had slept there the night before. Slept in shifts, one of us always listening. I was so goddamned tired.

But I had learnt what happened when you stopped sleeping. I had learnt what happened when you decided you could endure one more night, remain watchful for a few more hours.

I had learnt by watching Helen.

My wife. Lucy's mum.

She had insisted upon keeping watch during the first week after the blackout. Said I needed the rest. Said she would be fine.

After roughly three days, her eyes began to change. By the fourth night, she was no longer my wife.

I forced the thought down. I could not go there. Not now.

The scratching did not return. This time I counted to three hundred, making myself wait until I was certain. Lucy remained frozen beside me, gripping my hand so tightly that my fingers were going numb.

'All right,' I whispered. 'We're clear.'

She did not relax. Clever girl.

I had learnt about the skinning two weeks into hiding. Perhaps three. Time became slippery underground.

Lucy and I had still been holed up in our tenement flat off Renfield Street, rationing tinned food and bottled water, keeping the windows covered and moving only when we had no choice. I had gone out for supplies, only as far as a small newsagent three streets away. In and out. Fifteen minutes at most.

That was when I found Gareth.

Gareth Pritchard, our neighbour from two floors below. A big man, about 1.85 metres tall, who habitually wore a Celtic football shirt. He had once helped me wrestle a sofa up the tenement stairs. One Christmas, he had brought round shortbread made by his sister.

They had hung him from a street lamp at the junction of Sauchiehall Street and Cambridge Street.

I had almost passed beneath him in the dark. My torch was turned down to the faintest orange glow because I was trying to preserve the battery. But something made me look up.

They had peeled off his face. Not hacked it away. Peeled it carefully and precisely, leaving muscle and bone exposed. His eyelids were gone, so his eyes stared down, bulging and wet.

They had done the same to his hands, stripping them to the tendons, then hanging him by the wrists with what appeared to be electrical wire.

He was still alive.

His mouth moved when he saw me. No sound emerged. They had done something to his throat, I think, unless he simply lacked the strength to scream. But his lips formed the words.

Please. Please. Kill me. Please.

I stood there beneath my dying torch, looking at what they had done to Gareth Pritchard, and understood for the first time what we faced.

This was not chaos. This was not people losing their minds in the dark. It was deliberate.

It was territorial. A warning to anyone who entered their hunting ground.

I did not kill him. I should have. I should have found some way to end his suffering.

Instead, I ran. I sprinted back to the flat with my heart hammering and my hands shaking so violently that I could scarcely work the locks.

We left that night. Took whatever we could carry and went below, into old Subway infrastructure, abandoned railway tunnels and unrecorded service passages. Into the deepest places, where perhaps the sleepless would not follow.

That had been almost four months ago. About one hundred and twenty days of hiding, though the number no longer felt real.

The tunnel was silent now apart from the steady drip of water and Lucy's quiet breathing. I let myself relax a fraction, my shoulders dropping perhaps a centimetre.

'Dad,' Lucy whispered.

Her voice was tiny.

'Are they gone?'

'Yes, sweetheart,' I said. 'They're gone.'

I was thinking about Helen when we pushed through the bent security gate at the Tesco Metro on Sauchiehall Street. I could not help it.

During the first week after the blackout, she had decided one of us needed to keep watch. It had made sense at the time. We did not know what was happening, why the electricity had not returned or why the streets had fallen silent except for the screaming that began around the fourth day.

Helen stayed awake the first night while I slept with Lucy tucked against my chest. She did the same on the second. I told her to rest and let me take over, but she waved me away.

She said she was not tired.

Her eyes looked bright, too bright, and she paced from the sitting-room window to the kitchen and back again.

On the third night, I woke to find her standing over Lucy's mattress, watching her. Not moving.

Her pupils had spread so wide that I could barely see the brown of her irises.

'Helen,' I had whispered. 'Come to bed.'

She did not turn. She did not acknowledge me at all.

On the fourth night, she stopped blinking. By the fifth, her skin looked grey beneath the candlelight, papery and wrong.

I tried to take her arm and make her lie down, but she twisted away with a movement that was not quite human. Too fluid. Too precise. Her joints bent at angles that clenched my stomach.

On the sixth night, she went for Lucy.

I had dozed off. I should not have, but three hours of sleep in six days will do that. I woke to Lucy screaming, a sound I had never heard from her before.

Pure animal terror.

Helen had pinned her against the wall. Her fingers were locked around Lucy's throat, her jaw opening so wide that I could see every tooth, and she was trying to bite my daughter's face off.

I hit Helen with the aluminium cricket bat we kept beside the door. Hit her hard enough for the crack to echo through the flat.

She did not fall.

She turned on me instead, those reflective eyes catching the candlelight, and I saw nothing in them that remembered who I was.

It took three more blows before she fled. She smashed through the flat door and vanished down the close, moving on all fours faster than any human being should have been able to move.

Lucy bore the bruised prints of her mother's fingers around her neck for two weeks.

The Tesco was dark, with only grey winter daylight filtering through the filthy windows at the front. The electrical blackout left Glasgow black at night and dim even by day, beneath December cloud. Lucy stayed close to my left side, one hand clutching my jacket.

We had learnt to move quietly, stepping around the debris scattered across the lino: broken glass, crushed boxes and other things I did not inspect too closely.

Most of the shelves near the entrance had been stripped weeks before. We made for the back, passing the empty fruit and vegetable section, which stank of rot and mould, and the freezer cabinets that had not been cold in months. The stench made my eyes water. Lucy pressed her sleeve over her nose.

Tinned food should have been in aisle seven. I remembered that from before, when shopping meant taking a trolley and wondering whether to buy branded goods or settle for the supermarket's own.

The shelving had collapsed across the aisle.

I nearly turned back. Its metal frame had buckled, spilling tins and boxes across the floor in a tangle that would make noise if we tried to cross it.

Noise meant risk.

Lucy tugged at my jacket and pointed.

Between the fallen display and the back wall, I saw dark blue fabric. Beneath it lay the pale curve of a hand.

My first thought was that it belonged to a corpse. We had found three bodies in the past month, all at different stages of decay. People who had starved or been caught by the sleepless.

I began pulling Lucy away.

The hand moved.

I froze. Its fingers flexed slowly and deliberately. Then the hand withdrew into the shadow beneath the shelving.

'Hello?'

My voice came out hoarse. I had not spoken above a whisper for days.

Silence. Then a faint, muffled groan.

I looked at Lucy. Her eyes were enormous in her thin face, but she nodded. We had seen enough death. If someone was alive, we had to help.

'We're going to get you out,' I called, more quietly. 'Don't move, all right?'

It took twenty minutes to shift enough of the display. However carefully I worked, metal shrieked over the floor. Every sound tightened my shoulders as I waited for scratching to begin above us.

But the shop remained quiet except for our breathing and the groan of steel.

The woman underneath appeared to be in her early thirties. Dark hair spread around her head. She wore smart office clothes that looked clean.

Far too clean.

My mind caught upon that detail and would not release it as I pulled the final piece of shelving aside. No dirt. No rips. Her white blouse still held crisp creases in its sleeves.

Lucy crouched beside her while I checked for injuries. I saw no blood and no obvious broken bones. Her eyes were closed, her breathing shallow.

'Is she sleeping?' Lucy whispered.

The question made my hands tremble. Nobody slept deeply any longer. Nobody could afford to.

Yet the woman's face was smooth and peaceful. There were no lines of exhaustion cut around her eyes and mouth. No dark circles. Her skin had a healthy colour rather than the grey pallor worn by everyone still alive.

I touched her shoulder.

'Can you hear me?'

Her eyelids fluttered open. Brown eyes, clear and alert. Pupils that contracted normally in the dim light.

'Oh, thank God.'

She blinked at me, then at Lucy, then at the fallen display.

'What happened? Did the ceiling...'

She tried to sit and winced.

'How long was I unconscious?'

'Take it slowly.'

I helped her sit against the wall.

'You were beneath the shelving. Does anything hurt?'

'My shoulder. My head.'

She touched her temple, probing gently with her fingertips.

'Did the lights go out? I can barely see.'

'The lights?'

I stared at her.

'What?'

'The electricity.' She looked around the ruined shop, confusion drawing lines across her forehead. 'Did the storm cause a power cut? Someone ought to ring ScottishPower. This is ridiculous.'

She fumbled in her pocket, took out a mobile phone and pressed its button. The screen remained black.

'My battery's gone. Do you have a phone?'

Lucy's hand slipped into mine.

'What's your name?' I asked.

'Ruth Fairburn. Look, I appreciate the help, but I need to ring my office. I'm already late, and my manager is going to...'

She stopped. For the first time, she truly looked at us.

At my torn jacket and greasy hair. At Lucy's hollow cheeks and filthy clothes. At the shattered windows and debris surrounding us.

'What day is it?' she asked slowly.

'18 December 2018.'

The colour left her face.

'That isn't funny.'

'I'm not joking.'

'It's August.' Her voice sharpened. 'The twenty-eighth. I came here after work to buy school stationery for my nephew. The shop was crowded. There were people everywhere. Then something fell, and...'

She looked at the collapsed back-to-school display. A packet of 24 HB pencils lay split among the wreckage. Then she looked at the empty shop.

'Where is everyone?'

I did not know how to answer. I did not know where to begin.

'It's December,' I said again. '18 December. The blackout began on 20 August, nearly four months ago.'

Ruth shook her head.

'No. That's impossible. I was talking to Janine at work this morning. We went to lunch at that sandwich place near the office, the one that does the good turkey club. The city centre was packed. The office was... Everything was normal.'

Her hands twisted together in her lap.

'I remember getting into my car and driving here. The car park was full. I had to circle twice before I found a space. There were people shopping inside. The tills were working. The lights were on. All the lights were on.'

She looked at me with those clear, rested eyes.

'I was only shopping for back-to-school stationery,' she whispered. 'That was all.'

I watched Ruth struggle to process what I had told her. Her mouth opened and closed without producing words. She looked at me, then Lucy, then me again.

'I don't understand. What do you mean, the whole city is dark?'

Her voice rose.

'ScottishPower or the network operator only needs to restore the grid. There are procedures for this sort of thing. Hospitals have emergency generators. There are backup systems.'

'There's nobody left at ScottishPower,' I said. 'There's barely anybody left anywhere.'

She shook her head so hard that her dark hair swung across her face.

'That isn't possible. You're describing infrastructure collapse on a scale that would require...'

She stopped and began again.

'The government has contingency plans. The council, the emergency services, the Cabinet Office, the Army...'

'Gone,' I said flatly. 'Or changed. Or dead.'

Lucy drew nearer to my leg. I could feel her watching Ruth with the careful stillness she had learnt over the previous months, judging whether a stranger was dangerous, whether she might snap.

Ruth pressed both palms against the floor. Concrete grit scraped under them.

'You keep saying changed. Changed into what?'

I had known this part was coming. I knew she would not believe it without seeing for herself. People never did.

In October I had tried to warn a group sheltering in the Grand Central Hotel that the sleepless were organising, that they now hunted in coordinated packs. They laughed and called me paranoid. Two volunteered to watch the perimeter that night and stayed awake beyond their limits. By morning, they had torn apart three people in the lobby before the others drove them out.

'Come with me,' I said. 'I'll show you.'

Ruth did not move.

'Show me what?'

'What happens when people don't sleep.'

I led them deeper into the shop, beyond the collapsed display in aisle seven and the in-store chemist's counter, where the security grille hung loose. The smell worsened as we went. It was no longer merely the rot from the freezer cabinets, but something sharper.

Ammonia. Copper. Spoilt meat.

Lucy knew where we were going. Her hand found mine in the dark and squeezed once. Warning me or steadying herself, I could not tell.

Ruth followed a few paces behind, breathing too loudly in the enclosed space.

'I don't understand what you're trying to...'

The clicking began before I could answer. Soft at first, almost hidden by water dripping from a broken pipe overhead. Then louder and rhythmic, coming from the stockroom door ahead, which hung half off its hinges.

Ruth stopped.

'What is that?'

'One of them,' I said. 'One of the sleepless.'

The clicking changed, growing faster. Excited.

I raised my voice but kept it level.

'Judith. Judith Hargreaves. I know you're in there.'

Something pale shifted in the darkness beyond the doorway, too quickly for my eyes to follow. The clicking became a sustained rattle. Beneath it, I heard wet, laboured breathing, air passing through a throat that no longer worked properly.

'Jesus Christ,' Ruth whispered.

Judith crawled through the doorway. She did not walk. She crawled with her spine bent wrongly and her head tilted at an angle that would have broken a normal person's neck.

Her grey hair hung in clumps around her face, exposing patches of scalp that had acquired the same papery texture as her skin. She had once been wearing a cardigan. Its remains clung to her shoulders, shredded and stained.

But it was her hands that always caught me.

Her fingers had lengthened at the joints until they resembled spiders' legs. Each ended in a curved claw that scraped the lino as she moved. Her nails had continued growing after she ceased to be human, hardening into something better suited to what she had become.

Ruth made a noise. Not quite a scream. More as though all the air had escaped her lungs at once.

Judith's head swivelled towards it. Her jaw dropped open, not like a yawn but like an unfastened trap. The bones separated until I could see the teeth that had grown over the previous weeks: needle-sharp, packed close, made for tearing rather than chewing.

Her eyes caught what little grey light reached us from the broken roof panels and reflected it back.

That uncertain cat's-eye comparison again. Except Judith's eyes did not glow. They gathered the light and returned it cold and flat, like mirrors reflecting nothing but hunger.

'She was a teacher,' I said, keeping my voice steady. 'Garnetbank Primary School. She taught Primary 4 for twenty-four years.'

Judith tilted her head the other way. The clicking began again, softer now. Almost curious.

'After the blackout, she stayed awake to help run the primary school rest centre with the council. Roughly eighty hours before anyone realised something was wrong. By then, her pupils had already begun changing.'

I watched Judith shift her weight, testing whether we would approach.

'That's the first stage. The eyes change. Then the skin turns grey and loses its elasticity. That's the second.'

Ruth had backed into the wall, one hand covering her mouth.

'The third is when they stop blinking. They stop doing all the unconscious little things that make them appear human. Their movements change. They become smoother. More efficient. Predatory.'

Judith demonstrated by flowing almost a metre forwards without appearing to move her limbs. One moment she was there, and the next she was closer.

'The fourth stage is coordination. They form pack structures. That's when the deliberate clicking begins. Different patterns mean different things: hunting calls, territorial warnings, challenges over status.'

Judith clicked three times, sharp and quick. Something deeper in the stockroom answered.

'There's more than one,' Ruth said.

Her voice had become thin and high.

'There's always more than one now. They move in packs of five to eight. It lets them cover more ground and coordinate ambushes.'

I stepped back, drawing Lucy with me. Judith tracked the movement but did not follow.

'The fifth stage is what you're seeing. The final form. The teeth come in, the fingers lengthen and the jaw restructures. Their senses improve. Better hearing and smell. Sight adapted to the dark. But they lose everything else. Empathy. Recognition of the people they knew. Human reasoning. All that's left is the hunt and the pack.'

Judith hissed. No human throat should have made that sound.

'They see us as prey now,' I said. 'Nothing more. And they're patient. They'll follow a target for days, wait for the right moment, separate the weak and herd them into an ambush. They aren't mindless. They've adapted to this new world faster than we have.'

Ruth slid down the wall until she was sitting on the floor.

'That isn't possible. People don't simply... You can't transform like that. It isn't biologically feasible.'

'Tell that to Judith.'

I gestured towards the thing that had once taught nine-year-olds.

'Or all the others I've watched undergo the same changes. It takes roughly six weeks if they remain awake throughout. Seventy-two hours for it to begin. Six weeks to finish.'

The clicking sounded again from inside the stockroom. Closer this time.

'We should go,' Lucy said quietly.

She was right. Judith had not attacked, but that did not mean she would not. I had learnt to read their behaviour over those months. At that moment, Judith was observing us, cataloguing possible prey and judging our numbers and strength.

If her pack arrived, if they decided we were worth the effort, that calculation would change very quickly.

I pulled Ruth to her feet. She did not resist. She only stood staring at Judith with the kind of shock that meant her mind was still trying to reject what her eyes had shown her.

'Come on,' I said. 'We need to move.'

We reached aisle seven before Ruth stopped and doubled over, hands on her knees, breathing as though she had run a marathon. Lucy stood about a metre away, watching the shadows. Always watching now.

'This isn't real,' Ruth said. 'It's some sort of... I'm hallucinating. The display struck my head. I'm unconscious, and all this is...'

'It's real.'

I kept my eyes on the stockroom entrance. There was no clicking, but that did not mean they were not following.

'The blackout began on 20 August. Nearly four months ago. Anyone who remained awake for more than seventy-two hours after it started changing.'

'But I was just...'

She stopped and pressed both hands to her temples.

'The twenty-eighth. I thought it was 28 August when I came here. I remember finishing quarterly reports. I needed supplies for my nephew before school started. The twenty-eighth.'

There was something in the way she said it that made me pause. Not certainty now, but the desperate grasping of a mind shaken by terror.

'You said that before,' I told her. 'But think about it. What happened at work that day? Something concrete.'

Ruth closed her eyes.

'Janine mentioned her plans for the August bank holiday weekend. She said it was coming up, but not immediately. And there was a meeting that morning. The Wednesday meeting.'

Her face changed.

'No. Not the twenty-eighth.'

She searched her pockets and found her mobile again, though it remained dead.

'I sent the quarterly figures by email before I left. The message was dated 15 August 2018. Wednesday, 15 August. I left work at half past five and drove straight here.'

The date hit me harder than any scream could have.

'The blackout began on 20 August 2018,' I said. 'At 20:43 BST.'

Ruth lifted her head.

'That's impossible. On 20 August I was going to be at home. Everything was supposed to be normal.'

'What date did you come to the shop?'

'15 August 2018,' she said without hesitation now. 'Wednesday. I know it was. The email proves it.'

'Five days,' I said. 'Five days before the blackout.'

I looked at Lucy, then back at Ruth. My mind tried to process it and failed.

Until then, I had wondered whether she had come from somewhere the blackout had not reached. Some pocket of civilisation that still had electricity and functioned while everything else collapsed. A geographical anomaly beyond whatever area the first reports had covered.

But she remembered 15 August, and the blackout had not begun until the twentieth.

'You're not from somewhere else,' I said. The words felt strange in my mouth. 'You're from some time else.'

Ruth stared at me. Lucy's hand found mine and squeezed.

The clicking resumed behind us. Distant, but coming nearer. I knew we had to move.

For one moment, though, I stood in the ruined Tesco holding my daughter's hand and looking at a woman who had entered a working shop five days before the world ended, then stepped out almost four months later into the wreckage where we had been surviving ever since.

I stood in aisle seven while the clicking closed in from the stockroom, Ruth pressed against the wall and trying to rationalise impossible biology, Lucy's hand tight in mine.

But my mind had caught upon something else.

Ruth came from before. Five days before the blackout, she had entered a functioning supermarket with lights, tills and people buying school stationery. Then she had appeared on 18 December 2018 among transformed predators in a city without electrical power.

That meant she had entered somehow.

'We need to move,' I said.

I pulled Ruth upright again and guided Lucy towards the bent security gate. The clicking followed but did not quicken. Judith and whatever waited behind her were not hunting yet.

They were tracking us. Marking our position.

We emerged on to Sauchiehall Street. It lay empty in both directions, the buildings dark beneath a marginally lighter winter sky. December cold bit through my jacket. Ruth folded her arms across her body.

'This isn't... I don't understand how...'

'Later.'

I scanned the street and listened. No scratching from the buildings. No clicking.

'Lucy, are you all right?'

'Yes.'

She stayed close to my leg, staring at the shop as though Judith might crawl out after us.

I steered them back towards the hidden entrance into our underground route. My mind would not stop working at the problem.

Ruth had entered on 15 August and emerged on 18 December. For her, nearly four months had collapsed into nothing. Yet she had crossed that distance somehow. Perhaps there was a door that worked both ways. Or at least a route we had not found.

If she had come in, perhaps we could get out.

The thought struck my chest with something I had not felt in months. Not hope. Hope was dangerous. Hope got you killed when you took foolish risks to chase it.

But possibility. A direction that involved more than surviving one more day in the dark.

'Where did you park?' I asked Ruth, keeping my voice low. 'On 15 August, when you came here. Where was your car?'

She blinked at me.

'The multi-storey on Cambridge Street. Why does that...'

'Do you remember walking from there to the shop?'

'Of course. I came out on Cambridge Street, walked along Renfrew Street and turned towards Sauchiehall Street. It was crowded. There were people everywhere.'

Her voice faded as she studied the abandoned cars, broken windows and empty pavement.

'And you don't remember walking back.'

'I remember nothing after the display fell.'

She touched her head tentatively.

'There was a noise, a metallic screech, and everything came down. I must have struck my head, but I don't feel... There isn't even a wound.'

Because she had not lain physically pinned beneath that display for almost four months. Its fall had coincided with something else, and whatever that crossing was, she had experienced no time within it.

We reached the entrance I had forced open weeks earlier. I led them down concrete steps and into the dark, then took out my torch.

Its battery was weakening. The beam shone yellow rather than white and barely pushed back the shadows.

Lucy knew the way. She moved ahead, one hand trailing over the tiled wall, navigating by memory in the poor light. Ruth stayed close behind me, breathing too quickly.

'We'll follow the tunnels,' I said without looking back. 'West first, beneath the city centre, then north through an old railway maintenance link. There's a route that should bring us near Cambridge Street, close to the car park.'

'The tunnels reach that far?'

'They go almost everywhere. Subway works, disused railway lines, service passages, extensions that were built and never used. I've been mapping them for nearly four months.'

That was not entirely true. I had been surviving in them. Learning enough routes to remain ahead of sleepless patrols. Finding the deepest holes whenever the scratching drew close. But I had covered distance, and I knew the rough shape of the underground network.

If Ruth had crossed from August into December near that Tesco, perhaps the place where her journey began - the car park, the street works or one of the underground access points nearby - was a weak place. A fracture in whatever held us here.

The alternative was worse.

The sleepless controlled Glasgow. Every exit we had attempted - the Clyde crossings, the M8, the M74 and the main roads out of the city - was blocked. Not with barricades, but with their own bodies.

Packs dozens strong, organised into shifts that never slept and never stopped watching.

I had assumed they were guarding territory and protecting their hunting grounds. But if Ruth was right, if she had arrived from before, perhaps they were not guarding borders.

Perhaps they were maintaining something that had nothing to do with distance.

My mouth went dry.

Lucy reached the maintenance passage we had used as a sleeping place. A small alcove opened beside it, with a standard green illuminated fire-exit sign hanging by one bolt, long dead.

She waited for us there.

'We're not stopping?' she asked.

'Not yet. We're going farther today.'

She did not argue. She nodded and resumed walking when I caught up.

Ruth's breathing had steadied.

'You think I passed through some sort of temporal anomaly? That isn't... It's science fiction.'

'So are people who never sleep turning into predators with claws and eyes made for darkness.'

I swept my torch across the tunnel ahead.

'Everything is science fiction now.'

We walked in silence for a while. Every tunnel carried the same smells: rust, standing water and concrete slowly dissolving. The dripping changed from section to section, faster or slower, high or low. I had learnt to navigate as much by sound as sight.

Fear rested in my stomach, cold and heavy.

If I was right about the sleepless guarding a temporal boundary, if their intelligence truly increased with every sleepless hour, then perhaps they knew things we did not and understood things we could not.

Ruth's appearance might not have been an accident or a fracture in their control.

She might have been bait.

We were going anyway. The alternative was to remain underground until our supplies were exhausted or the sleepless finally found us.

At least this gave us direction. A purpose beyond lasting another day.

We reached the disused lower platforms beneath St Enoch station forty minutes later. I knew the place from earlier scavenging trips. It was a broad open space with high ceilings and platforms at several levels, part forgotten railway work and part service interchange. It was dangerous because of the exposure, but unavoidable if we meant to reach the passages running towards Cambridge Street.

I stopped at the entrance passage and raised one hand to halt Lucy and Ruth.

I listened.

The smell reached us first. Copper, ammonia and something organic and wrong. The stockroom stench from the Tesco, concentrated until it was thick enough to taste.

'Stay close,' I whispered. 'Don't make a sound.'

We entered the station.

My torch swept across the platform and caught the edges of abandoned kiosks and old service booths. The ceiling rose about nine metres into the darkness, too high for the dying battery to illuminate.

Something clicked above us.

I froze. Lucy became rigid against my leg. Ruth caught her breath.

Another click answered from the left, then a third from the right. This was not the rapid clicking Judith had used while tracking prey. It was slower. Almost conversational.

I raised the torch.

The beam found them in fragments. A pale arm hanging down, fingers tipped with claws. A twisted spine bent backwards. A face with reflective eyes that seized the light and returned it cold and flat.

They clung upside down to old pipes and electrical conduits, their heads angled to watch the platform beneath them.

Dozens of them. Perhaps more beyond the reach of my light.

A feeding ground. They brought prey here, or waited for it to pass.

The smell came from old kills, bones and tissue cached in the shadows.

Ruth made a small noise in her throat.

One of the sleepless clicked three times, sharp and questioning. Another answered with two.

Every step echoed from the tiled walls and rose to the ceiling where they waited. My boots scraped the concrete, impossibly loud within the station's hollow acoustics.

They heard it. Every one of them.

Their heads followed the sound in perfect unison. Dozens of reflective eyes turned towards us in the dark.

I held the torch upon the ceiling and kept my voice low and even.

'They're clever enough to set traps,' I said. 'They memorise short pieces of human speech and reproduce them to draw you in.'

Ruth's breathing caught behind me.

'I've heard it twice. Once near Glasgow City Chambers. A woman screaming for help. The same scream, the same words, repeated about every forty-five seconds. Exactly the same each time.'

Lucy's hand clutched my jacket near my hip.

'The second was a child crying for his mum in the Merchant City service tunnel. A perfect sequence. No variation and no breaths between the sobs.'

I lowered my voice further.

'So whatever you hear below ground, no matter how much it sounds like someone needs help, ignore it. Keep walking. Don't answer. Don't investigate. Don't even look towards the sound.'

'How do you know it's them?' Ruth whispered. 'How do you know it isn't real?'

'Because real people don't last long enough to call for help twice.'

The clicking above us changed pattern. Three short bursts from the left. Two longer ones from the right.

Communication, perhaps. Coordination.

I lowered the beam and allowed darkness to swallow the hanging figures again.

'Stay close. Watch your footing. Don't touch the walls unless you have to.'

We began crossing the platform. I angled the failing torch towards the tiled floor.

With every step, the smell grew stronger.

Copper and ammonia, and something else beneath them. Something sweet and rotten that clung to the back of my throat. The first body lay about a metre from the platform edge. I couldn't tell much about who they had been.

The sleepless had processed them thoroughly. They had stripped away the flesh in systematic patterns, leaving only bone and sinew in careful arrangements. The skull sat apart from the vertebrae, positioned precisely 30 centimetres away. Both femurs lay parallel, clean and white.

Lucy made a small sound and looked away.

'Over here,' I said, guiding them to the left around the remains. 'Step where I step.'

More bodies were scattered across the platform as we moved deeper into the disused lower levels beneath St Enoch station. Some were fresh enough that I could distinguish their decay from the ambient rot. Others had been reduced to skeletal frameworks arranged by the sleepless in patterns I did not want to understand.

A ribcage stood upright against the far wall, each bone interlocked with the next in a structure that should not have been possible. Three skulls formed a triangle near the tunnel entrance, their empty sockets all facing inwards towards a central point marked with dark stains.

Ruth stumbled and caught herself against a support pillar, then jerked her hand back as if the concrete had burnt her.

'Keep moving,' I said.

The clicking followed us across the platform, tracking our progress from above. I counted the sounds without meaning to. Seven distinct sources now, perhaps eight. More than when we had first entered.

They were converging on our position, drawn by the noise, the movement and the promise of fresh prey.

We reached the tunnel entrance on the south side of the platform. The darkness ahead looked absolute. My torch beam barely penetrated five metres before the shadows swallowed it completely.

Water dripped somewhere in the distance, each drop echoing from tile and concrete in a rhythm that almost matched the clicking above.

'How far?' Ruth asked. Her voice shook.

'About 800 metres to the next access point. Then we cut north-west towards Cambridge Street.'

I led them into the tunnel, one hand holding the torch and the other resting on Lucy's shoulder to keep her close. The walls pressed in on both sides, narrower than the main passage we had used earlier. My boots splashed through standing water pooled beside the old rails, and the smell shifted from rot to rust, mould and wet stone.

Behind us, the clicking grew louder.

They were following now, no longer merely tracking. I could hear claws scraping over tile and concrete, and the wet sound of their breathing echoing down the tunnel.

'Ruth,' I said, keeping my voice low and level. 'When you were in that shop on 15 August, tell me exactly what you remember before the display fell.'

'I don't... Why does that matter now?'

'Just tell me.'

She breathed hard for three steps. Four.

'I was looking at school stationery. The back-to-school display near aisle seven. They had packs of pencils, 24 HB pencils. My nephew needed them for his school list.'

'And?'

'I reached for a pack on the top shelf. I had to stretch. My fingers touched the cardboard and then...'

She paused.

'Everything went black. No transition and no warning. Just instant darkness, metal screeching and something pressing against my back.'

Lucy stumbled. I steadied her with a firm hand between her shoulder blades.

'When you woke beneath the fallen display,' I said, 'what did you feel?'

'Confused. Disorientated. But not injured, which doesn't make sense. Those shelves were heavy. I should have been...'

Ruth's voice caught.

'I should have been crushed, or at least hurt. Bruised. Something.'

The tunnel curved to the left, and the torch beam revealed more bones scattered along the tracks. Smaller ones this time. Finger bones, perhaps. Vertebrae. They had been arranged in a line stretching ahead into the darkness.

'Your clothes were clean,' I said. 'No dust, no blood. The creases in your blouse were still sharp.'

'I noticed that after you pulled me out. Everything felt wrong, but I couldn't... I didn't know why.'

We passed through a section where the ceiling had partly collapsed, leaving lumps of concrete and exposed reinforcing bars across the tunnel floor. I helped Lucy over the debris, then reached back for Ruth. Her hand was ice-cold when she gripped my arm.

'15 August,' she said, and her voice had changed. It was steadier now, more focused. 'I remember everything about that day. What I wore. What I had for breakfast. The email I sent to my supervisor before I left work. It was dated Wednesday, 15 August 2018. I remember Janine complaining that the office photocopier had jammed again. I remember the weather - partly cloudy, about 26 degrees, humid enough to make my hair frizz.'

The clicking behind us stopped.

Complete silence followed, broken only by our footsteps, our breathing and the drip of water somewhere ahead.

'I remember the radio in my car playing that song I hate, the one about summer nights. I remember the Cambridge Street multi-storey was crowded, and I had to park on the third level. I remember thinking I ought to get everything sorted before the bank-holiday weekend.'

She swallowed.

'That isn't normal. I shouldn't remember all of it. Not perfectly. Not every detail as though it had just happened. But I do. It is vivid and complete, like I'm still there, still living that Wednesday afternoon.'

'Because for you, it was,' I said.

'That's impossible.'

'Yeah.'

We walked in silence for another nine metres. The tunnel widened slightly and the smell improved, less rot and more ordinary damp and decay. My torch beam was noticeably weaker now, its yellow cast deepening towards orange.

Ruth spoke again, more quietly.

'What if it isn't only me? What if the whole city...'

She stopped walking. I turned back.

She stood in the middle of the tunnel, her clean white blouse reflecting what little light remained.

'What if Glasgow is stuck?' she said. 'Trapped in these days, from 20 August until now, repeating them while the world outside keeps moving forwards in normal time? What if we're caught in a loop, and the blackout keeps happening, and people keep transforming, and-'

'Ruth.' I kept my voice gentle. 'We need to keep moving.'

'But it makes sense. It explains why nobody came to help. Why there was no rescue, no proper government response. Beyond the city, perhaps none of this is happening. Perhaps it's still August or September and everything is fine, while we're trapped here and time is doing something wrong.'

Lucy tugged at my jacket. I looked down, and she silently formed one word.

'Coming.'

I heard it then. Not clicking this time, but footsteps. Several sets, moving quickly through the tunnel behind us. Human footsteps.

Then came a voice, clear, desperate and utterly convincing.

'Please, somebody help me. I can hear you ahead. Please, don't leave me here.'

Ruth turned towards the sound. I seized her arm hard enough to bruise.

'Ignore it,' I said. 'Move. Now.'

The voice came again, closer.

'I'm hurt. I can't walk. Please, I've got children. Please help me.'

I pulled Ruth forwards. She resisted for one second, then two, before she began walking. The footsteps behind us accelerated into a run.

Clicking erupted from everywhere at once. It was no longer behind us, no longer coming from a single direction I could map and avoid. It echoed along the tunnel from ahead, from the sides and from passages I had not even known were there. Seven distinct sources became twelve, then fifteen, then too many to count.

They had been herding us.

The realisation struck with the same sick certainty I had felt on the morning I found Gareth Pritchard hanging from that streetlight. They had been driving us towards this exact section of tunnel all along.

I stopped. Ruth collided with my back, breathing hard through her nose. Lucy pressed herself against my leg, her fingers twisting so tightly in my jacket that the fabric pulled across my shoulders.

'Daniel?' Ruth's voice came out thin and high.

The clicking shifted and synchronised.

Three sharp bursts from the northern tunnel entrance were answered at once by three from the south. Then two sounded from somewhere to the east, near the web of old Subway works and railway maintenance passages. The rhythm was too precise to be random communication.

Someone was coordinating them.

Something was giving orders.

I had heard stories about the pack leaders from other survivors, back when enough people remained alive to exchange information. Lucy and I had hidden in a church basement for five days in October while a group of scavengers traded accounts of sleepless who retained enough human intelligence to organise hunts.

Most of the transformed lost everything that had made them people. They operated on predatory instinct, hunting, feeding and marking territory without any recognisable thought behind those reflective eyes.

But a few retained something.

Perhaps they were the ones who had stayed awake longest before changing. Perhaps they had been tactical thinkers before the blackout. Whatever the reason, they remembered strategy. They understood coordination.

They led the others through the city in patterns that resembled military operations more than animal behaviour.

The clicking came again. Four short bursts from directly ahead.

Then silence.

Lucy's breathing changed, becoming the shallow, rapid pattern she used when she was trying not to cry. I put a hand on her head and felt her greasy, matted hair beneath my palm.

We had been running for nearly four months. She had been terrified for nearly four months.

Nine years old, and she had watched her mother change into something that tried to kill her. Then she had spent about 120 days hiding in darkness while creatures that had once been human hunted her through the ruins beneath her city.

'Ruth,' I whispered. 'You said you know a way out.'

'I...'

She stopped and tried again.

'The multi-storey on Cambridge Street. I parked there on 15 August. I walked along Renfrew Street to Sauchiehall Street, through a city that still had people in it.'

My torch beam was orange now, fading towards red. I had perhaps ten minutes of light left. Maybe less.

'Yes.'

The clicking began again behind us, back towards the lower platforms beneath St Enoch. It was measured and rhythmic. Something large moved through the tunnel at walking pace, unhurried because it knew we had nowhere to go.

I counted eight distinct sources converging from the rear in perfect synchronisation. Eight sets of claws on concrete. Eight sets of enhanced predatory senses fixed on our scent, our movements and the carbon dioxide in our panicked breaths.

'Daniel, we need to move.' Ruth gripped my shoulder. 'Now.'

I did not move. I could not.

Because this was the choice, here in the tunnel, with my daughter shaking against my leg and clicking closing in from every direction.

Either Ruth Fairburn had somehow fallen through time and could lead us back to August, when the world still made sense, or she was the most sophisticated bait I had ever seen. A woman with clean clothes and clear eyes, planted in the Tesco Metro on Sauchiehall Street with a perfect story about 15 August, designed specifically to lure desperate survivors into whatever trap the sleepless had prepared beneath the city.

The tactical ones were intelligent enough to do it. Intelligent enough to understand that humans would trust another human who seemed untransformed, confused, frightened and lost. Intelligent enough to turn that trust against us.

'Daddy.'

Lucy's voice was barely audible. She had not called me that in weeks. Lately she had called me Daniel, using my first name because somewhere in those nearly four months she had stopped being a child and become a survivor.

Hearing that word now, in this tunnel, with those things closing in from every direction, I made my decision.

'Go.'

I pulled Ruth forwards and guided Lucy ahead of me with a hand on her back.

'Cambridge Street. Show us.'

We ran.

The tunnel floor was uneven, cracked concrete and pooled water splashing beneath our boots. My torch beam jerked and swayed, painting orange streaks over walls covered in decades of grime and mineral deposits.

The clicking behind us erupted into a chorus. At least twenty distinct voices now, joined by wet breathing and the scrape of claws on stone.

They had been waiting for us to move. Waiting for us to commit to a direction so that they could close the trap.

Ruth led us deeper into the southern tunnel, past a collapsed section where reinforcing bars jutted from broken concrete, then towards a junction I had never explored. The smell changed. There was less rust and stagnant water, replaced by disturbed earth and something chemical I could not identify.

The walls narrowed until my shoulders almost brushed both sides. Lucy ran ahead, her smaller frame passing through the confined space more easily than Ruth or me.

'There.' Ruth pointed to where the tunnel curved left. 'That maintenance passage. I remember. When I walked from the car park to the shop, there were roadworks near Cambridge Street and Renfrew Street. They had opened part of the street, and I could see through a grate into old workings beneath it. A tunnel or service passage.'

An access point that had existed in August but might be sealed now, buried beneath months of debris, blocked by the sleepless or simply gone. Nothing from August was guaranteed to exist in December.

The clicking behind us stopped.

That was worse.

The silence pressed against my ears, filled with our own footsteps and breathing. When the sleepless went quiet, it meant they were close enough to change from tracking to attacking. Close enough that they no longer needed to communicate because their prey was in sight.

I risked a glance backwards.

My dying torch caught movement nine metres away. A pale figure crawled along the tunnel ceiling, its spine bent backwards at an impossible angle, its head turning to follow us with eyes that reflected the orange light.

It was not Judith Hargreaves. This one was larger, broader across the shoulders, wearing the shredded remains of a high-visibility security jacket. Something metal was still pinned to its chest.

An identity badge.

A former security guard. It had to be the tactical leader the other survivors had warned about, the one who had retained enough human intelligence to organise hunts across several territories.

Tariq something. Tariq Donnelly. That was it. Someone in the church basement had known him before.

They said he had worked for Clyde City Security at one of the city-centre office buildings. He had stayed awake for six straight days during the first week after the blackout, trying to protect people. He had organised watches, rationed supplies and kept everyone calm even as the world collapsed around them.

Then he had changed.

And when Tariq changed, he had retained that organisational ability, that tactical precision, that understanding of how to coordinate a team.

Except now his team was a pack of twenty sleepless moving through the tunnels in perfect formation, and the people he had once protected were prey he hunted with brutal efficiency.

Tariq clicked once, sharp and commanding.

Every sleepless in the tunnel answered in unison.

Then they charged.

I heard them coming, that distinctive sound of too many limbs moving too quickly over stone. Lucy screamed, a short burst of pure terror that ricocheted from the walls.

Ruth grabbed my arm and hauled me forwards with surprising strength, pulling me around the curve towards the maintenance passage she had indicated.

The walls changed.

Not slowly. Not gradually.

Between one step and the next, decades of grime and decay flickered and became clean, cream-coloured tiles, whole and unblemished. Then they returned to rot, then became clean again, oscillating like a failing fluorescent tube.

The concrete beneath my boots looked solid and newly poured for half a second, then cracked and water-stained, then pristine once more. The smell shifted from mould and rust to nothing, to fresh concrete and the particular chemical tang of new construction materials, then back to decay.

'What...'

I could not finish the question.

Ruth's August was bleeding through.

It was the network of passages beneath the roadworks she had crossed on 15 August, when crews were working around Cambridge Street and the city still had power, when people walked above us and carried on with their ordinary lives. That reality was here, overlapping our December wasteland, occupying the same physical space but separated from us by nearly four months and the end of the world.

The walls flickered faster. Clean, decayed, clean, decayed. My torch beam looked wrong against the shifting surfaces, sometimes reflecting from pristine tile, sometimes swallowed by crumbling concrete.

Lucy stood frozen in the centre of the tunnel, staring at her hands as they alternated between bright visibility and deep shadow, depending upon which version of the passage surrounded us from one second to the next.

Behind us, Tariq's clicking changed pitch. For the first time, it sounded uncertain.

The charging slowed, then stopped.

The sleepless had reached the boundary where August and December overlapped, and they did not understand what they were seeing.

Neither did I.

I followed Ruth into the flickering section with Lucy's hand locked in mine and Tariq's clicking echoing from the walls behind us.

The concrete under my boots kept changing, smooth and freshly poured one moment, cracked and water-stained the next. My torch caught the oscillation in frozen glimpses, revealing cream tiles that became mould-covered decay in the space of a breath, and electrical conduits shifting between bright new copper and corroded green metal.

Ruth moved quickly, her clean smart office clothes standing out against the filth as if she had stepped in from another world.

Which, I supposed, she had.

15 August 2018. Five days before everything ended.

Lucy stumbled, and I hauled her upright without breaking stride.

Behind us, the clicking intensified. Tariq was coordinating his pack through that commanding rhythm he had developed.

Three sharp bursts. Responses from several sources.

Then silence, which meant they were moving.

The smell continued to change. Wet concrete and rust became fresh paint and construction dust, then changed back again. My stomach lurched with every transition, vertigo striking in waves as reality failed to decide which version it wanted to be.

Ruth reached the maintenance passage she had indicated, a narrow opening in the left-hand wall marked by a rusted grate hanging from one hinge.

Except the grate was not rusted any more.

It gleamed, silver and new, in my dying torchlight. Beyond it, metal stairs led upwards where the collapsed rubble I had mapped three weeks earlier should have been.

'Here,' Ruth said. 'This connects to the surface near Cambridge Street and Renfrew Street.'

I looked back.

Tariq had rounded the curve, crawling across the ceiling with that impossible bend in his spine. His high-visibility security jacket hung in shreds, but the metal identity badge caught my torch beam. The words Clyde City Security and his name remained just legible.

His eyes reflected the light, flat and cold, their pupils fully dilated. He clicked once, a command.

The answer came from everywhere.

Twenty voices at least. Perhaps thirty. Wet breathing filled the tunnel like an approaching wave.

'Move,' I said, pushing Lucy towards the maintenance passage.

Ruth went first, squeezing through the narrow opening. Lucy followed, and I came last, my shoulders scraping both sides as I forced myself through.

The metal stairs beyond were solid beneath my boots. There was no rust and no structural damage. Fresh welds shone at the joints.

Behind us, Tariq reached the opening. I heard his claws scrape against the metal as he tested the gap. He clicked twice in frustration.

The passage was too narrow for his transformed body.

But the others would try. The smaller ones. Judith Hargreaves, with the slight frame she had carried through twenty-four years of teaching Primary 4 before beginning to change after roughly eighty hours awake. The teenage boy I had seen near the Merchant City service tunnel. The woman who had once worked in a coffee shop near the tenement flats off Renfield Street.

I climbed. Ruth's footsteps rang on the stairs above me. Lucy was between us, breathing hard.

My torch beam jerked across concrete walls that flickered between decades of water damage and fresh construction. The smell oscillated too. Mould and standing water became sawdust and wet paint, over and over, until I stopped trying to decide which was real.

Thirty steps. Forty.

My legs burnt and Lucy's breathing became ragged, but I did not slow. Below us, the clicking followed, echoing up the stairwell in overlapping patterns.

Ruth reached the landing and stopped. I nearly collided with Lucy's back.

'What?' I began.

'Here,' Ruth said. 'The breach is here.'

I looked past Lucy and understood what she meant.

The air itself was wrong at the top of the landing. A vertical line divided reality. On the left, I could see the concrete stairwell ceiling, cracked and stained by nearly four months of decay. On the right, the same ceiling looked freshly poured and clean, with working fluorescent fittings mounted at intervals of about two metres.

The boundary between them shimmered. It was not quite visible, but I could feel it, the way one senses the edge of a drop in darkness.

Lucy made a small sound.

'Daddy.'

'It's all right, baby.'

I did not know whether that was true.

Ruth stepped towards the shimmer and extended her hand.

'When I touched the display on 15 August, I fell through into December. This is the same thing, but reversed.'

Below us, the clicking grew louder and closer. I counted at least six separate sources climbing the maintenance stairs.

'We go through,' Ruth said. 'We return to 15 August 2018, five days before the blackout.'

I stared at the impossible boundary. My torch beam struck the shimmer and divided into two beams, each bending at an angle that hurt to look at.

'And if we don't?'

'They catch us.'

Ruth's voice remained calm, but her hand was shaking.

'Tariq and his pack. We die here in December, in the dark.'

The clicking reached the first landing beneath us, about six metres away, then five.

I gripped Lucy's shoulder and pushed her towards Ruth.

'Go.'

Ruth took Lucy's hand and stepped into the shimmer.

They both disappeared.

They did not fade or dissolve. They were simply gone, as though someone had cut them out of reality with scissors.

I looked back once.

Tariq's reflective eyes appeared around the bend in the stairwell below, his body flowing upwards with a predator's grace. He clicked three times, commanding his pack, claiming his kill.

I stepped through.

The sensation struck me in the gut. I was falling and rising at once. Pressure built in my ears and behind my eyes. The temperature surged hot, then cold, then hot again. My lungs seized. I could not breathe, could not think, could not-

My boots struck concrete. Solid. Real.

I stumbled forwards and caught myself against a wall that did not crumble beneath my palm. Smooth painted plasterboard, slightly warm.

My torch was gone, dropped somewhere in the transition, but I did not need it. Fluorescent lights hummed overhead. Actual electric lights, bright enough to make me squint after nearly four months of darkness.

I stood in a maintenance corridor beneath street level. The walls were cream-coloured and clean. The floor was smooth concrete, with fresh yellow paint marking safety zones. Electrical conduits ran along the ceiling in orderly bundles, secured by proper mounting brackets and connected to labelled junction boxes.

No rust. No water damage. No smell of decay.

Lucy stood about two metres away, Ruth's hand resting on her shoulder. Both of them stared at me with wide eyes.

Lucy's face looked strange in the artificial light. I had grown accustomed to seeing her in darkness and shadow. The fluorescent glare revealed how pale she had become, how deep the exhausted circles beneath her eyes were and how much weight she had lost from her already slight frame.

'Daddy.'

Her voice cracked.

I went to her and pulled her against my chest. She gripped my jacket in both fists and pressed her face into my shirt. I felt her whole body shaking.

'We're all right,' I said into her greasy hair. 'We're all right.'

Ruth walked to the end of the corridor, where metal stairs climbed towards a door beneath a standard green illuminated fire-exit sign. She went up three steps and pushed the door open.

Sunlight poured through.

Actual sunlight, golden and warm.

I heard traffic, car horns, a distant siren, and voices talking and laughing somewhere above us. They were the sounds of a living city.

Lucy pulled away from my chest and looked up at me.

'Is it real?'

'Yes, baby. It's real.'

We climbed the stairs together. Ruth held the door as we emerged near the junction of Cambridge Street and Renfrew Street.

I stopped on the pavement and stared.

People were everywhere. Dozens passed on either side of us. Men in suits spoke on mobile phones. Women in summer dresses carried shopping bags. Teenagers clustered around a Glasgow bus stop, sharing earphones. A street-food van on the corner was selling kebabs, its vendor calling to passers-by.

Cars filled the road, stopping and starting beneath traffic lights that actually worked. The signals cycled from green to amber to red in perfect rhythm. The sun hung low in the western sky, perhaps an hour from sunset.

It was warm, about 24 degrees, with late-summer heat still clinging to the pavement.

I looked at Lucy.

She stood frozen with her mouth slightly open, watching a woman push a pram past us. A sleeping baby lay inside. The woman glanced at us, particularly at Lucy, taking in the filthy clothes and matted hair. Then she quickly looked away and carried on walking.

We looked wrong here. Three people who had crawled out of hell into an ordinary Wednesday afternoon.

'15 August 2018,' Ruth said quietly. 'About half past five. I was walking from the Cambridge Street multi-storey along Renfrew Street towards the Tesco Metro on Sauchiehall Street at around this time, in the future we just left.'

I took my mobile phone from my jacket pocket. I had not thought about it in weeks. Its battery had died in October.

I stared at the dead black screen.

A man walked past, speaking loudly into his mobile about a conference call. His voice held that cheerful irritation people used for ordinary frustrations at work.

Normal.

Everything was normal.

'Five days,' Ruth said. 'The blackout begins on 20 August 2018 at 20:43 British Summer Time.'

'You said that before, in the tunnel.'

I nodded, my throat tight.

'We have five days to stop it.'

I looked at her.

'Stop it how?'

'I don't know what caused it. The power failed everywhere at once.'

'Then we find out what caused it.'

Ruth spoke with the same calm determination she had shown below ground.

'We have five days, and we know exactly when it happens. Most people never get that much.'

A First Glasgow bus pulled up across the road, its brakes hissing. The teenagers climbed aboard, still sharing music and laughing. The bus pulled away and merged with the traffic.

Lucy tugged at my jacket.

'Are we going to see Mum?'

The question struck me like a blow to the chest.

Helen.

Right now, at this exact moment, Helen was alive and human. She was probably in our tenement flat off Renfield Street, making tea, watching television or doing any of the thousand ordinary things she had done before the blackout took everything.

'I don't know, baby.'

'We have to warn people,' Ruth said. 'Police Scotland, the Scottish Government, the UK Government, ScottishPower and the electricity network operator. Someone who can-'

'And tell them what?' My voice came out harsher than I intended. 'That a national grid failure will begin in five days and that anyone who stays awake too long afterwards will turn into a monster? That the first changes begin after about seventy-two hours, and that after six weeks they become those things? Do you think anyone will believe us?'

Ruth's jaw tightened.

'We have to try.'

I looked around at the normal city humming with life. Thousands of people were going about their Wednesday evening, unaware that in five days their world would end. Radio reports after the blackout had suggested failure across Great Britain and disruption farther afield, though we had never learnt how much of that was true.

The people around us would die in the initial chaos, transform into sleepless predators or end up hiding in darkness as Lucy and I had. Millions across Britain might suffer the same fate.

Unless we stopped it.

The weight settled upon me slowly, like stones being added to my shoulders one at a time.

We stood five days in the past with knowledge of exactly what was coming. Every choice we made from this moment would help determine whether the blackout happened at all. Whether Helen refused sleep during that first terrible week and changed. Whether she attacked Lucy. Whether my daughter spent nearly four months terrified beneath Glasgow, watching her mother become a predator. Whether millions lived or died.

But warning people was not enough. We needed evidence they could test.

First, I had to contact Helen. We had to verify Ruth's dated memories - her work email, the meeting that Wednesday, the car park, the roadworks and every detail that placed her here on 15 August 2018. We had to find the point where the breach had formed and work out whether it was connected to the shop, the street works, the multi-storey or the passages below. Then we could approach Police Scotland, the network operator and the governments with something more convincing than a story about monsters in the dark.

I crouched in front of Lucy and looked into her face in the golden sunlight.

'We're going to fix this, all right? We're going to make sure none of it happens.'

She nodded slowly, searching my eyes for a certainty I did not feel.

I stood and looked at Ruth.

'Where do we begin?'