The Five Rules of Black Crag

The Puma's rotors were still hammering the air when I jumped down onto the frozen landing site on 10 October 2026. My Bergen hit the icy ground with a thud that bounced from the mountain ridges around us. October in a remote Highland glen north-west of the Cairngorms was not merely cold. The wind chill made my teeth ache and numbed my fingers through my gloves.

I grabbed my kit and jogged clear of the helicopter, head bowed against the downdraught. The pilot gave me a thumbs-up through the window. Then the Puma lifted away, leaving me in front of what would be my home for exactly six months.

Black Crag Signals Station looked just like the briefing photographs: four principal prefabricated buildings enclosed by a 3.6-metre weldmesh security fence topped with concertina wire. Aerials and radio masts reached into the grey sky, their red warning lights blinking steadily. Watchtowers stood at intervals along the perimeter.

Beyond the fence lay many miles of empty moor, forest and mountain ground. Scots pine and birch crowded the nearer slopes, giving way to dark forestry plantations that looked as if they had been there since the beginning of time. The nearest inhabited settlement and all-weather road were several hours away.

"Mercer."

I turned. A man was walking towards me from the operations building. He was tall and straight-backed, with a weathered face that made his age impossible to guess. His uniform was immaculate despite the wind. The name tape read HARGREAVES.

"Yes, Staff Sergeant."

I straightened and adjusted my grip on the Bergen.

"Welcome to the arse end of nowhere." He did not smile. "Follow me."

We crossed the compound in silence. I counted the four main buildings from the briefing: the accommodation block, the operations room, the stores and generator shed, and the cookhouse. Everything was functional and severe. Grey metal cladding, small windows, heavy doors. A few soldiers moved between the buildings, but not many. Black Crag operated with a complement of twelve personnel.

Staff Sergeant Hargreaves led me into the operations building, along a narrow corridor and into a small office. Maps covered the walls: topographical surveys of the glen, radio-frequency charts and weather records. He sat behind a metal desk and opened a drawer.

"Before we get you settled, there is something you need to see."

He took out a sheet of paper. It was not official stationery, just an ordinary page covered in handwriting, and slid it across the desk.

I picked it up and read.

"Rules for guard duty and general conduct.

"One: do not respond to voices calling from outside the fence after dark, no matter who they claim to be.

"Two: do not allow anyone inside the perimeter who arrives on foot. No exceptions.

"Three: if any animal speaks, do not acknowledge it and continue with assigned duties.

"Four: lock your door before 00:00 and keep it shut until dawn. Do not open it for any reason.

"Five: if you hear screaming at night, do not investigate. Radio the operations room and remain at your post. If off duty, stay locked in your room."

I read the list twice, then looked up. Hargreaves's expression had not changed. He still wore that flat, unreadable stare.

"Is this some kind of initiation?"

"Those are standing orders for Black Crag."

"Come on, Staff. Talking animals? Voices in the night?" I put the paper back on his desk. "I understand. New bloke arrives and everyone has a bit of fun. Fair enough. It is a squaddie wind-up."

"Pick up the paper, Mercer."

There was an edge to his voice now. Not anger exactly, but something harder.

I picked it up.

"You will memorise those rules. You will follow them. No exceptions and no questions. Is that clear?"

"Yes, but-"

"Is that clear, Lance Corporal?"

I folded the paper and put it in my pocket.

"Yes, Staff Sergeant."

"Good. Corporal Rahman will show you to your room. You have the midnight shift in Watchtower Two tonight. Get some rest."

He returned to his paperwork, dismissing me. I waited for a moment, expecting him to crack a smile or offer some sign that it was all a joke.

Nothing.

Corporal Tariq Rahman turned out to be a thin man of twenty-nine with tired eyes and a small crescent pendant visible at his collar. He helped me carry my kit to the accommodation block, a long, narrow structure divided into individual rooms.

"This is yours," he said, opening a door near the end of the corridor. "Not much, but at least it is private."

The room was roughly 2.5 by 3 metres. It held a single bed, a locker, a small desk, a rifle rack and an even smaller wardrobe. A narrow window overlooked the fence and the forest beyond.

"Thanks."

I dropped my Bergen on the bed.

"What is the story with those rules Hargreaves gave me?"

Tariq paused in the doorway.

"He gave you the list?"

"Yes. Come on, mate. Speaking animals? It is a joke, isn't it?"

He looked at me for a long time. There was something in his expression that I could not place at first. Pity, perhaps, or worry.

"Just follow them," he said quietly. "Trust me."

Then he left me alone.

I unpacked slowly, hanging my uniforms in the wardrobe and arranging my personal things on the desk. The rules remained folded in my pocket, and I found myself taking them out to read again.

The whole thing was ridiculous. I had served at Catterick Garrison, with British Forces Germany and on a posting in Cyprus. Every place had its traditions and its ways of breaking in new arrivals. This one was simply more elaborate than most.

I tried to sleep before my shift, but sleep would not come. The wind howled outside and made the walls creak. Somewhere in the building, a door slammed. They were ordinary sounds, but at Black Crag they seemed louder and more threatening.

At 23:45, I made my way to Watchtower Two. The soldier I relieved, Private Owen Price, looked barely old enough to shave. He handed me the logbook without a word and hurried towards the accommodation block.

The tower was a raised platform enclosed on three sides, with windows overlooking the perimeter. A small heater buzzed in the corner, losing its battle against the cold. I settled into the chair and opened the logbook.

Page after page contained the same routine entries: weather conditions, visibility, security checks, nothing unusual to report.

At 01:00, I wrote my first entry.

01:00. Lance Corporal Mercer on duty. All clear.

The first half-hour passed quietly. Every fifteen minutes, I swept the searchlight along the fence. I was not sure what I expected to find. Red deer, perhaps. A stray stag. The briefing had mentioned wildlife, but the fence seemed excessive for animals.

At 01:30, something changed.

The wind died completely. An absolute silence descended, so deep that my ears rang. There was no rustle of branches, no movement in the undergrowth, nothing except the heater's buzz and my breathing.

Then I heard it.

"Daniel."

I froze.

The voice came from beyond the fence, perhaps 45 metres into the trees. It was a woman's voice, soft and familiar.

"Daniel, pet. Is that you?"

My mother's voice. Impossible, but unmistakable.

I stood and moved towards the window. The searchlight cut through the darkness, revealing only trunks, branches and shadows.

"Daniel, please. I'm hurt. I don't know how I got here."

My hand reached for the tower door, then stopped.

Rule One. Do not respond to voices calling from outside the fence after dark.

I pulled my hand away.

"Pet, please. It's so cold. I think I've broken my ankle. I can see the lights, but I can't find the gate."

Every word was perfect. The familiar soft Geordie inflection I had grown up hearing. The way she called me pet when she was frightened, though in ordinary conversation she had stopped doing it years ago.

It was her.

Except it could not be. Mam was alive and safe in Newcastle upon Tyne, probably asleep in her flat. She did not even know the exact location of my posting.

"Daniel, why won't you answer me? I'm scared."

I gripped the edge of the desk until my knuckles whitened.

The voice began to move around the perimeter, always outside the fence, always just beyond the searchlight's reach.

"I know you're there. I can see you in the tower. Please, just say something. Let me know you can hear me."

My mouth opened. The words "I'm here" reached the tip of my tongue.

I bit them back and remembered Hargreaves's face.

No exceptions. No questions.

The voice continued for another hour, pleading, weeping and begging. It knew things. It used my childhood nickname. It recited the little bedtime rhyme Mam had made up when I could not sleep, a rhyme known only to the two of us.

At 03:00, its tone changed.

"You're really not going to help me? Your own mother?"

Anger crept into the familiar voice.

"I raised you better than this. What sort of son leaves his mam to die in the cold?"

I stayed silent, staring into the darkness. My hands shook as I wrote in the logbook.

03:00. Unusual auditory phenomenon beyond perimeter. No visual contact. Fence secure.

The voice became colder.

"I'm not the only one out here, Daniel. The others aren't as patient as I am."

A laugh drifted through the trees. It was not my mother's warm chuckle but something that made every hair on my arms rise. It started low and climbed, multiplying until it sounded as though a dozen throats were laughing in harmony.

The sound circled the tower, drawing closer, then receding, then closing in again. I gripped my rifle and checked that a round was chambered, although I had no idea what I might shoot.

The laughter continued until dawn. Sometimes it formed words I could not understand. Sometimes it became screams, sobs or noises that were not quite human.

When the first pale light touched the ridges, the laughter stopped halfway through a note, as though someone had thrown a switch.

I sat shaking, sweat soaking through my undershirt despite the cold. The forest looked ordinary again, nothing but trees, shadows and morning mist. Birds began to call. The wind returned.

At 06:00, Tariq arrived to relieve me. He took one look at my face and nodded.

"First rule?"

I nodded, not trusting my voice.

"That one usually comes first."

He poured coffee from a flask and handed me the cup.

"It gets easier. Not better, but easier."

"What was it?" My voice came out rough.

"I don't know. I don't want to know. Follow the rules and you might get through your six months."

I handed him the logbook and returned to the accommodation block on unsteady legs. In my room, I unfolded the list and read it again.

This time I did not read it as a joke or a new-starter initiation. I read it as a warning. As survival instructions.

I memorised every word.

About two weeks passed. By then, the fence had stopped feeling like a precaution and begun to feel like the only thing between us and whatever lived in the forest.

I adapted to the routine faster than I expected. I woke at 14:00 and ate in the cookhouse while the day shift had their evening meal. Equipment checks began at 16:00, followed by either watchtower duty or perimeter security patrols until 06:00. The rota kept us moving and focused. It stopped us thinking too much about what we heard after dark.

On the night of 24 October, I was assigned to patrol the perimeter, checking the fence for damage and confirming that every gate was secure. The temperature had fallen by another ten degrees since my arrival.

My breath clouded in front of me as I walked, boots crunching over frozen ground. I was halfway around my second circuit when I saw him.

A man stumbled out from between the Scots pines about 45 metres from the main gate, moving as though every step hurt. Even at that distance, I could see that his clothing was torn. His walking trousers were ripped at the knees and his checked shirt hung open despite the cold.

He lurched forwards, one hand pressed to his ribs. When he saw me, he raised the other.

"Hey! Thank God. Hey!"

His voice carried across the open ground, hoarse and desperate.

"Please, I need help."

I stopped. My hand moved instinctively towards my rifle, not aiming it at him, merely ready.

He continued across the rough ground between the trees and the perimeter. As he came closer, I saw blood on his shirt, dirt ground into his face and a cut on his forehead that had bled into his right eye.

He collapsed against the gate and wrapped his fingers around the weldmesh.

"Please. You've got to let me in. I've been lost for three days."

"How did you get here?"

"I was hillwalking with friends. Fog came down near the ridge and we got separated. I fell, or there was a stag... it charged out of nowhere. I don't know. I think my ribs are broken. I've been walking for hours trying to find help."

His story sounded possible. Black Crag was isolated, but Scottish long-distance paths and estate tracks crossed the wider region. Hillwalkers and wild campers sometimes strayed from them. People became lost in sudden fog. Accidents happened.

I moved closer but kept about 6 metres between us. Up close, he looked worse. His lips were cracked and bleeding, perhaps from dehydration. The blood on his shirt had dried to a rusty brown. His hands shook against the fence.

"Where is your kit?"

"Dropped it. Yesterday, maybe. It was slowing me down and I had to keep moving." He pressed his forehead to the mesh and closed his eyes. "Something was following me."

He swallowed.

"Look, I know this is some sort of military site, but I'm badly hurt. Please."

I reached for my radio, then hesitated.

Something about him felt wrong.

No. That was paranoia. The man was clearly in distress. He needed warmth, water and medical attention. Compassion and every instinct drilled into me during training demanded that I help him.

My hand moved towards the gate release.

Rule Two.

Do not allow anyone inside the perimeter who arrives on foot. No exceptions.

I stopped.

"I'll radio the operations room," I said. "We can request a military CASEVAC helicopter. The weather and distance may delay it, but help will be sent."

"What? No. Just open the gate."

He rattled the fence. Desperation sharpened his voice.

"I'm right here. Let me inside, then call whoever you need. I'm freezing."

"I cannot do that. I can radio for CASEVAC and mountain rescue support."

"How long?"

"I don't know."

"I could be dead before they arrive. What the hell is wrong with you?"

I unclipped my radio without taking my eyes off him.

"Operations, this is Mercer on perimeter. I require-"

The change happened so quickly that I nearly missed it.

His face shifted. The bones beneath the skin moved as if the flesh had become soft clay. His jaw thrust out and kept extending, revealing teeth that lengthened into points. The fingers gripping the fence stretched. His nails became slate-grey, hooked blades. His eyes turned glossy black, each marked by a narrow vertical pupil.

It snarled, producing a noise no human throat could make, and hauled on the fence hard enough to shake the entire section. Metal groaned but held.

Those elongated hands thrust through the gaps and slashed at me.

I stumbled backwards and dropped my radio.

"Let me in."

The hillwalker's voice remained within the sound, but other tones now layered it, deeper and hungrier.

"I'm so tired of waiting. So tired of asking nicely."

The thing pressed its distorted face against the mesh. Its tongue was too long and too dark, protruding through the gaps. It dragged at the fence with impossible strength, and I heard metal beginning to tear.

I brought my rifle to my shoulder and stepped back again.

"Stop or I'll fire."

It laughed like glass being ground beneath a boot.

"Yes. Make noise. Bring the others running. They will have to open the gate then, won't they? They will have to help their injured friend."

The logic struck me cold.

If I fired or raised a general alarm, the others would come. In the darkness and confusion, they might see only a wounded civilian at the gate. Would they remember Rule Two, or would their training take over - help the casualty first and ask questions later?

The creature seemed to read my hesitation. It pulled harder, and a support post groaned. Another minute might have brought the section down.

Then, as suddenly as it had begun, it stopped.

The thing released the fence and stepped away. Its hideous features were already flowing back into a human arrangement. Within seconds it resembled the injured hillwalker again, although something in its eyes remained wrong.

"Clever lad," it said in a normal voice, which somehow made it worse. "You're learning. But you cannot watch every gate every night. Winter is coming, and the cold makes us so much hungrier."

It turned and walked towards the forest. There was no stumbling now. Its stride was purposeful and smooth.

Just before it reached the trees, it looked back over its shoulder.

"Tell the Staff Sergeant his fence will not hold for ever. Tell him we remember every face that has denied us entry."

Then the forest swallowed it.

I stood for a long time with my rifle half raised, staring at the place where it had vanished. My hands would not stop shaking.

At last I recovered my radio and resumed the patrol. I checked every centimetre of the section it had pulled. The weldmesh was stretched in several places, and a support post bore a hairline crack.

I reported the physical damage but said nothing about the encounter. What could I have passed up the chain of command? Injured hillwalker transformed into an inhuman creature and threatened future attacks? I would have been removed from duty and sent for psychiatric assessment.

Over the following week, I threw myself into work. Maintenance, stores checks, inventory - anything that kept me occupied. Sleep became more difficult. Whenever I closed my eyes, I saw the face changing and those hands reaching through the fence.

But the rules had saved me. Obeying them, even when every instinct had screamed at me to help, had kept that thing outside.

The following week, during an afternoon inspection of the stores, I heard barking.

A Border Collie sat outside the fence, its tail wagging and its tongue hanging out in what looked like a friendly smile. It was a beautiful animal, with a thick black-and-white coat and alert ears. It looked like a trained mountain-rescue dog, the sort of animal that might appear on a rescue charity poster or alongside a police dog unit.

I ignored it and returned to the inventory.

The barking continued, punctuated by small whines. After several minutes, I made the mistake of glancing through the window.

The dog had moved closer to the fence. It sat with the perfect posture of a trained working animal. When it saw me looking, it tilted its head and wagged its tail harder.

"Hello there, soldier."

I nearly dropped the clipboard.

The voice came from the dog, clear as ordinary speech, although its mouth did not move as it should have. The words simply emerged from it.

"I know this is strange," it continued, "but I need help. I'm lost. I caught the scent of a red deer and bolted after it. Lost my owner on the hill. Stupid, I know. I've been out here for days and I'm so hungry."

I turned back to the inventory and gripped the clipboard.

Rule Three. If any animal speaks, do not acknowledge it and continue with assigned duties.

"I can see you," the Border Collie said. "I know you can hear me. Look, I understand. A talking dog is fairly odd, isn't it? But I'm not a monster. I'm a pet that was dealt a strange hand. A research experiment that went wrong, if you want the truth."

I counted the ammunition.

"My owner works at a research facility outside Aberdeen. Please. Just some food and water."

The voice was reasonable and genuinely pitiful. It reproduced in sound the expression dogs used when begging beneath a dining table. Every word pulled at the human instinct to help an animal in distress.

I forced myself to continue.

Twelve crates of 5.56 mm rounds. Eight crates of 9 mm rounds. I marked the figures on the form.

"You're frightened. I understand. This place isn't normal, is it? I've seen things outside. Horrible things. They hunt at night. They take the weak and the lost. I've been hiding, but I cannot keep running."

I checked the next shelf.

"Let me in. I'll be good. I can help you watch for them. Dogs hear things humans cannot."

Signal flares. First-aid packs. Generator spares.

"Please."

Its voice broke as if it were crying.

"I'm so tired of being alone. Do you know what it is like to have thoughts, to be able to speak, but have nobody listen? My owner probably thinks I'm dead. I only want to go home."

I finished with the ammunition and moved on to the medical supplies.

The Border Collie kept talking as I crossed the stores, its voice following me through the building. Sometimes it begged. Sometimes it chatted as though we were old friends.

It told me about its owner, Dr Imogen Shaw, a research scientist who loved hillwalking. It described its favourite toys and how much it missed sleeping on a proper bed instead of frozen ground. Every detail was perfectly chosen to make me want to help.

To make me forget that dogs did not speak, regardless of what might have happened in a laboratory. To make me ignore the exact danger covered by Rule Three.

After twenty minutes, its tone changed.

"You're really not going to help me, are you?"

The warmth drained from its voice.

"That is cold, mate. Truly cold. What sort of person ignores a talking dog? Do you know how special I am? How valuable? Dr Shaw would pay thousands of pounds to get me back. Any scientist would."

I finished the inventory and headed for the door.

The dog paced back and forth along the fence.

"But no. You are going to let me starve because of a stupid rule. Fine. Be that way. But you are making a mistake. I could have been an ally. I could have warned you about what is coming, because they are coming."

I stepped outside and walked towards the operations building without looking at it. The Border Collie followed on the far side of the fence, matching my pace.

"Those things that pretend to be people are only scouts. They are testing your defences. The real hunters are much worse."

I kept walking.

"Do you think that fence will protect you? Do you think those rules mean anything to the old ones? They are amused by you, playing your little games and following your little lists. But when the storms come and the daylight shortens, that is when they feast."

The dog stopped at the corner of the perimeter, unable or unwilling to follow farther.

As I reached the door, it called one final time.

"When you hear them crying inside the walls, remember that I could have helped. I would have been a good dog."

I went inside and shut the door firmly behind me.

Through the window, I watched the Border Collie sitting at the corner of the fence, staring at the building. After several minutes it stood, shook itself like an ordinary dog and trotted into the forest.

That evening in the cookhouse, I sat opposite Tariq while we picked at reconstituted eggs. He took one look at me and raised an eyebrow.

"Which rule today?"

"Three."

He nodded slowly.

"The dog?"

"Border Collie."

"That is the form most people see. Rule covers any animal, though. That one is difficult. It sounds so real, doesn't it? So ordinary, apart from the obvious."

"What are they?" I asked quietly. "What do they want?"

Tariq pushed the eggs around his plate.

"Does it matter? They are outside and we are inside. The rules keep it that way. That is all we need to know."

But I could see that he had asked the same questions. He had lain awake wondering what kind of world we inhabited, where creatures wore human faces, animals spoke with human voices and a mother's perfect imitation called from an impossible distance.

We finished eating in silence.

Outside, the wind strengthened and rattled the windows. Something howled in the distance. It might have been a fox or a dog.

Or it might not.

I no longer wanted to know. I wanted only to reach 10 April 2027 with my sanity intact.

I could not stop checking locks.

After the Border Collie, I developed a routine that bordered on ritual. I tested my door handle three times before bed. I checked the deadbolt twice, then once more for good measure. Tariq had caught me doing it a few nights earlier and merely nodded. He understood without an explanation.

Everyone at Black Crag had a way of coping.

The paranoia arrived gradually. During shifts, I counted the rules in my head and matched each one to a finger like a child learning arithmetic.

One: do not answer voices beyond the fence after dark.

Two: nobody arriving on foot enters the perimeter.

Three: if any animal speaks, do not acknowledge it and continue with assigned duties.

Four: lock the door before 00:00 and keep it shut until dawn.

Five: do not investigate screams at night.

Simple, precise and lifesaving.

I began carrying a notebook and recording anything unusual. It was not intended for official reports. It was for me alone: patterns in the sounds outside, unexplained falls in temperature and sections of fence showing the greatest wear.

I thought that if I understood the logic, I might predict what came next. Perhaps knowledge would make it less frightening.

It did not.

Three days after the Border Collie, Staff Sergeant Hargreaves assigned me to a full maintenance inspection of the stores and generator shed. Every item had to be inspected, cleaned and catalogued before the Highland winter worsened.

I spent fourteen hours stripping generators, checking fuel lines and testing backup batteries. My hands became black with grease and my back ached from bending over machinery.

Tariq brought coffee at around the tenth hour.

"You look dreadful, Dan."

"I feel worse." I wiped sweat from my forehead and left another streak of grease. "How many of these ancient generators do we have?"

"Too many. But they are what keep the lights on when the main supply fails." He leant against the workbench. "Trust me, you do not want to be here in the dark."

By the time I finished, my thoughts had turned to mush. Every joint ached. My eyes burned from fluorescent light and diesel fumes.

I stumbled back to my room shortly after 22:00, so exhausted that I could barely direct my feet. The narrow bed, thin mattress and scratchy wool blanket looked like heaven.

I kicked off my boots without lining them up. I stripped off my grease-stained PCS shirt and combat trousers and let them fall on the floor. The pillow was cool against my cheek when I collapsed face-first onto the bed.

Sleep took me before another thought could form.

Cold woke me.

It was not the ordinary chill of a Highland night. It was deeper, like the air rushing from a freezer that had not been defrosted for years. My breath misted above the blanket. Ice crystals formed in the wool.

I opened my eyes to darkness.

The clock read 00:17.

Something moved at the edge of my vision.

My body went rigid. The primitive part of my brain recognised danger before my conscious mind understood what it had seen.

Slowly, resisting every instinct to close my eyes and pretend I was asleep, I turned my head.

It stood beside my desk, perfectly still.

The figure had to bow slightly beneath the ceiling. It was more than 2 metres tall, with limbs stretched far beyond human proportions. Its skin was so pale that it seemed to shine in the dark. Its fingers hung below its knees, each divided by too many joints.

Its face was worse.

Where its eyes should have been, there was only smooth skin. It was neither scarred nor sewn shut, simply a continuous plane of pale flesh from forehead to cheekbones. Its mouth was a thin line, barely visible until it opened.

"You forgot."

The whisper filled the room despite being softer than breath. Each word came from everywhere at once: the walls, the ceiling and the inside of my skull.

I could not move. My muscles had locked. Fight or flight had become absolute stillness.

The thing tilted its head as if studying me with senses that had no need of eyes.

"Rule Four," it whispered. "Such a simple thing. Turn a handle. Slide a bolt. But you were tired. So very tired."

It took a step closer. The vinyl flooring creaked beneath it. Its impossible fingers traced the edge of my desk and left trails of frost across the metal.

"Do you know what usually happens when someone forgets?"

Its head tilted in the other direction, owl-like.

"Would you like me to tell you?"

My throat worked, but no sound emerged.

The creature began circling my bed with slow, deliberate steps.

"First they take the small things. Childhood memories. The taste of your mother's cooking. The name of your first dog."

It paused at the foot of the bed.

"You do not notice at first. The mind fills the gaps. It invents explanations. Stress, the doctors say. Fatigue."

It resumed its circuit.

Now it stood on the other side of me, and I could smell wet stone, mouldering paper and stagnant cellar water.

"Then come the faces. Your sister becomes a stranger. Your best friend's features alter when you are not looking. You know something is wrong, but the words needed to explain it dissolve before they reach your tongue."

Its fingers brushed my locker, leaving frost patterns on the metal.

"The doctors call it Capgras syndrome. They give you pills that do not work."

It completed the circuit and stopped beside the desk. In the darkness, its pale form seemed to pulse with a sick light.

"Finally, when you are hollow, when everything that made you human has been carved away, they use you. A shell that walks and speaks but serves their purpose. Nobody notices because the outside still looks the same."

It bent down, bringing its eyeless face closer to mine. The cold intensified until my teeth chattered.

"But I am not like them. I remember when this glen held only trees, stone and snow, before your kind raised fences and wrote rules."

Its whisper became almost wistful.

"I am curious about you. About why you follow the rules so carefully... except tonight."

My voice returned as a dry croak.

"I was tired. I forgot."

"Yes."

It straightened until its head nearly touched the ceiling.

"Exhaustion. Such a human weakness. But perhaps a blessing. The others, the hungry ones, would already be wearing your memories like stolen clothes. I merely wanted to see."

"See what?"

"Fear."

The thin mouth stretched into something that might have been a smile.

"Pure, honest fear. It has been so long since I felt it. I wanted to remember."

The creature moved towards the corner. Its long limbs folded and adjusted in ways that hurt to watch.

"Lock your door, Daniel Mercer. Every night, without fail. The next visitor may not share my nostalgia."

It stepped backwards into the wall, not through a door or window but through the solid surface as though plaster and metal were mist. The wall showed no trace of its passage.

The frost on my desk and locker remained for several seconds, then evaporated. The room warmed so abruptly that my skin prickled.

I sat in the dark with the blanket pulled to my chin like a child hiding from monsters. Except the monsters at Black Crag did not live beneath beds. They passed through walls, spoke in whispers and remembered the world before people had names for it.

The clock read 00:34.

Seventeen minutes. The encounter had lasted seventeen minutes, although it had felt like hours.

Moving like an old man, I left the bed and crossed to the door. My hands shook as I tested the handle.

Once. Twice. Three times.

The deadbolt slid into place with a solid clunk. I checked it again and put my full weight against the door. It was firm. Secure. I had finally obeyed the rule.

I dragged the chair across the room and wedged it beneath the handle for good measure.

Then I sat on the bed with my back against the wall and waited for dawn.

Sleep was impossible. Every shadow concealed pale limbs. Every small noise threatened to become a whisper.

My notebook lay open on the desk, and I considered recording what had happened. But no words could capture the sensation of something ancient and wrong standing inside my room, calmly explaining how my memories, face and identity might be stolen piece by piece.

At 06:00, pale daylight crept through the window. I dressed in yesterday's uniform and went in search of coffee. My hands still trembled, though less visibly.

Several members of the day shift nodded to me in the cookhouse. Ordinary greetings. Ordinary routine, as though things did not walk through solid walls at night.

I never forgot to lock the door again.

Not once during the remaining months.

However heavy my eyelids became, however fiercely my body demanded sleep, I stood at that door and performed the ritual. Handle three times. Deadbolt twice, then once more.

The frost marks on the desk never entirely disappeared. Sometimes I ran my fingers over their faint patterns and wondered what would have happened if I had broken another rule. If I had answered my mother's voice on the first night. If I had opened the gate to the false hillwalker. If I had spoken to the Border Collie.

The visitor had called my exhaustion a blessing. It said the others would have been worse.

I believed it.

At Black Crag, I would accept seventeen minutes of terror over whatever alternative awaited those who failed Rule Four.

Lock your door before 00:00 and keep it shut until dawn. Do not open it for any reason.

Such a simple thing. Turn a handle. Slide a bolt.

I never forgot again.

By early November, checking locks, counting rules and jumping at shadows had become ordinary life. I had begun to sleep a little better, if four hours of restless turning could be called sleep. The memory of the pale creature had faded from sharp terror into a dull ache, like a bruise that hurt only when pressed. Some nights I reached morning without waking in a cold sweat.

Then, one night, screaming tore me from sleep.

It was high, piercing and desperate. A woman's voice, shredded by panic.

I rolled out of bed and struck the floor hard. Reflexes from training took over before my mind was fully awake.

"Help me! Oh God, somebody help me!"

The voice rebounded along the corridor and seemed to come from everywhere. It might have been near the eastern end of the accommodation block or outside by the stores and generator shed. The acoustics of the prefabricated buildings made its source impossible to judge.

All I knew was that somebody needed help.

Now.

I dragged on my boots without socks and snatched my rifle from the rack. I chambered a round. My PCS shirt hung over the chair, but there was no time. An undershirt and combat trousers would have to do.

"Please! He's trying to kill me! Somebody... anybody!"

The final word broke into sobs that made my skin crawl.

I had heard people cry out in pain during training and genuine medical emergencies. This was different. It was the voice of someone who knew she was about to die.

I reached the door at a run, rifle held at low ready. Beyond it, the corridor extended in both directions beneath harsh fluorescent lights that never quite reached the corners.

Empty. But the screaming continued, louder now that I was outside my room.

"Where is everyone?"

The woman's voice rose to a shriek that made my teeth ache.

How was no one else responding? There were twelve of us at Black Crag, yet I was the only person in the corridor. I started towards the east wing, where the sound seemed strongest.

A door opened behind me.

I spun, bringing my rifle up automatically.

"Dan, stop."

Corporal Tariq Rahman stood in his doorway wearing boxer shorts and a faded Royal Marines charity T-shirt left by a former flatmate. His hair stuck up at odd angles, but his eyes were alert and focused. He held his own weapon loosely at his side.

"Someone's in trouble," I said.

The words came out more harshly than I intended.

"We need to find out where she is."

He stepped into the corridor and blocked my path.

"Help me, please. He's coming."

The screams echoed between us. Tariq did not even flinch. He stood there as though we were discussing the weather while someone died nearby.

"Get out of my way."

I tried to step around him. He moved with me, still blocking the corridor.

"Tariq, I'm serious."

"Someone needs reminding of Rule Five."

His voice cut through another wail.

When you hear screaming in the night, do not investigate.

"I don't care about the bloody rules right now."

Even as I said it, my hands tightened around the rifle.

The rules. Always the rules. They had saved me from my mother's voice, from the thing at the gate and from the speaking Border Collie. But this was different.

This was human. This was real, and it was happening while we stood arguing in our underwear.

"Get away from me."

"No."

Something crashed. Glass shattered. Furniture overturned. The woman's screams took on a different quality, wet and gurgling, as though she were choking on something.

I pushed past Tariq, or tried to. For a lean man, he was stronger than he looked. He caught my shoulder, shoved me backwards and planted himself squarely in the centre of the corridor.

"You go out there, you don't come back."

There was no anger in his voice. He spoke as if stating a fact.

"How can you just stand there?"

My voice cracked. I sounded young and frightened, which was exactly what I was.

"She's dying."

"She's not dying."

Tariq lowered his weapon completely and let it hang from its sling.

"Come on. My room. Now."

"I'm not going to-"

"Dan."

He used the same tone Staff Sergeant Hargreaves had used on my first day, the one that permitted no argument.

"My room. Now."

The screaming changed again. There were several voices now, making sounds that turned my stomach. The original woman's voice layered itself over and over, creating a chorus of pain that seemed to press against my eardrums from within.

I let Tariq guide me into his quarters. He shut the door behind us and locked it, checking the handle twice and the deadbolt once. His room was identical to mine except for the personal touches: photographs taped to the wall, a framed family picture above the bed and a half-empty bottle of whisky on the desk.

"Sit."

He pointed to the desk chair. I remained standing, clutching the rifle in both hands. He shrugged and sat on the bed with his weapon across his lap.

"First time?"

"First time what?"

The screaming continued outside, muffled by the door but still audible. Still dreadful.

"The screamers." He rubbed his face with both hands. "Usually start on someone about this point. You're right on schedule."

"Somebody, anybody, please."

I flinched. Tariq did not. He had heard this before, many times, judging by his complete lack of reaction.

"Two years," he said quietly. "I've been at Black Crag for two years. Heard them perhaps thirty times. Forty. I stopped counting after a while."

"And you've never once..."

The unfinished question hung between us.

"My third week, just like you. I heard someone screaming, grabbed my weapon and went to help. Made it halfway to the stores and generator shed before Corporal Ellis tackled me and dragged me back inside. Saved my life."

The screaming outside changed position. Now it appeared to come from directly above us, although I knew the roof was empty. There was no way up without a ladder, and the access hatch was locked from within.

"Ellis rotated out four months later," Tariq continued. "But before he went, he told me about the ones who didn't listen. Private Callum Reid vanished about six months before I arrived. Heard screaming near the cookhouse and went to investigate. They found his rifle the following morning. Safety off, full magazine, no blood and no sign of a struggle. He was simply gone."

"Maybe he deserted."

The words sounded hollow even to me. Black Crag lay many miles from the nearest inhabited settlement or all-weather road, across empty moor, forest and mountain ground, and winter was closing in.

Tariq shook his head.

"Then there was Lance Corporal Aisha Khan, about eighteen months ago. Same thing. Screaming from the perimeter. She radioed the operations room to say she was going to check it. That was the last anyone heard from her. Search parties found her bootprints in the snow leading towards the fence. They stopped about six metres from the trees. Just stopped, as if she'd vanished in the middle of a step."

The woman's voice climbed to an impossible pitch and then split into three separate screams. One came from above, another from below and a third from somewhere to the east. The same voice, the same pain, arranged in impossible directions.

"Who's doing this to me?"

I put down my rifle and gripped the edge of Tariq's desk. My knuckles turned white. Every instinct told me to help, to do something, anything. But Tariq's words held me in place.

Reid. Khan. Gone.

"How long does it last?"

"An hour. Sometimes two."

He reached for the whisky bottle.

"Want some?"

I shook my head.

The screaming continued in a rhythm, rising and falling. A woman sobbed and begged, then shrieked in pain, over and over again.

"Why doesn't anyone else come out? Why aren't they responding?"

"They know the rule."

Tariq took a mouthful straight from the bottle.

"They've been here long enough to know what happens. They're probably lying in bed with pillows over their heads, waiting for it to stop. Anyone on duty will have radioed the operations room and stayed at their post."

"Help me. Help me. Help me. Help me."

The words ran together into one long wail. I wanted to cover my ears, but that felt like surrender. I was beginning to understand that there was no woman, only another thing wearing a human voice.

"Talk to me," I said. "About anything. Just talk."

Tariq nodded.

"My sister's getting married next month. December wedding. Mad, isn't it? Who gets married in December? She says the church looks beautiful with all the Christmas decorations."

He kept going, telling me about venues, catering and dress shopping. Normal things. Human things. Anchors to reality while the impossible moved through Black Crag.

The screaming changed. Several voices became a dozen, then more. They all belonged to the same woman at different ages. A child screamed for her mam. A teenage girl begged for help. An elderly woman croaked, "Please."

An entire lifetime of one person's pain had been compressed into a single simultaneous sound.

I gripped the desk harder.

Tariq continued talking about his sister's wedding, the DJ she had hired and the colour of the bridesmaids' dresses. His voice remained steady and calm, as though we were sitting in the cookhouse rather than hiding from whatever hunted through our corridors.

Then came silence.

It did not fade. The screaming stopped in the middle of a wail, leaving only the hum of the heating system and the sound of our breathing.

I checked my watch. It was 01:47. We had been in Tariq's room for fifty-three minutes.

"Is it over?"

"Wait."

Tariq raised one hand.

A single scream erupted directly outside his door. It was so close that I heard the intake of breath beforehand.

The handle rattled.

"Why won't you help me?"

The woman's voice was broken now.

"I can hear you in there. Two of you. Armed. Strong. Why won't you help me?"

Neither of us moved.

The handle rattled again, more violently.

"Fine."

The voice changed. It became something deeper and angrier.

"Fine. Let me die. But I won't be the last. I won't even be the worst."

Footsteps moved along the corridor. They did not sound like walking. Wet slaps struck the lino, like raw meat hitting the floor. They receded until I could no longer hear them.

After five minutes of silence, Tariq finally relaxed.

"Now it's over."

I stood on shaking legs. My rifle felt heavier than it should as I picked it up.

"Everyone who investigated vanished?"

He put the cap back on the whisky bottle.

"No bodies. No explanation. Just gone."

"Senior command must know."

"They have to. But what are they going to do? Close Black Crag? Admit that something here takes people who break the rules?"

"So we just let them scream."

"We follow the rules."

Tariq stood and checked his weapon automatically.

"That's how we make it home. That's the only way."

I moved towards the door, then stopped.

"The woman, the voice. Is it always the same?"

"No." He shook his head. "Sometimes it's a man. Sometimes children. Once I heard my mother, a perfect match down to her accent, screaming that someone was hurting her. That was a bad night."

I understood. If the thing had used my mother's voice again, screaming instead of calling from beyond the fence, I did not know whether Tariq could have stopped me.

"Thanks," I said. "For stopping me."

"Pass it on."

Tariq unlocked his door, deadbolt once and handle twice, reversing the order in which he had secured them.

"When the next new starter comes, you stop him. That's how it works."

I stepped into the corridor. Everything looked normal. There was no blood, no broken glass, no overturned furniture and no evidence that someone had been screaming for her life only minutes earlier.

There was a smell, faint and already dispersing: copper, ozone and something organic and wrong.

"Dan."

I turned back.

Tariq stood in his doorway, looking older than twenty-nine.

"Check your locks," he said. "Every night. No exceptions. And when you hear screaming again, because you will, remember that whatever makes those sounds isn't human. Never was. The ones who forget that are the ones who don't make it home."

I nodded and returned to my room.

It was early November. Five months remained. Five months of rules, monsters and things that screamed with human voices. But I would make it. I would obey every rule, no matter how hard my instincts fought me and no matter who appeared to need help.

Tariq was right. The only way home was to remember that nothing at Black Crag was what it seemed. Mercy and compassion could get you killed. Sometimes the most human thing you could do was nothing at all.

I locked my door, checked the handle three times and the deadbolt twice, then checked both once more for good measure. I sat on the bed with my rifle across my lap. Sleep was not coming back that night.

Outside, the wind howled through the mountain ridges, and every gust sounded like someone calling for help.

The remainder of the Highland winter passed without another direct test, but it was never peaceful. Short days gave way to long nights. Severe wind chill, snow and prolonged storms battered the four principal buildings, the watchtowers and the aerials. I followed every rule, completed every shift and checked every lock. The routine became vigilance, and vigilance became instinct.

On 10 April 2027, exactly six months after I arrived, I folded my last PCS shirt and placed it in my kitbag. The movements were automatic after years in the Army.

My quarters looked almost exactly as they had on 10 October 2026. Bare walls, standard-issue furniture and the single window overlooking the 3.6-metre weldmesh fence, the Scots pine and birch beyond it. Only the faint frost marks on the desk and the worn patch in the floor where I had checked the lock each night showed that I had ever been there.

The Puma was due in two hours. Two hours until I could leave Black Crag behind and pretend it had been another posting, another job completed.

I heard boots in the corridor, eager, quick steps of the sort only new arrivals made. Everyone else had learnt to move carefully there, conserving energy for when it mattered.

The footsteps stopped outside my door.

"Lance Corporal Mercer?"

The voice was young and energetic.

"I'm Private Owen Price. Staff Sergeant Hargreaves said you'd show me round before you leave."

I opened the door to find a lad who looked fresh from training. He had bright green eyes, a uniform so new that the creases had not yet softened and boots polished to a mirror shine. He stood rigidly, as though awaiting inspection.

"Dan is fine."

I stepped aside to let him enter.

"You can ease off the formality."

Owen relaxed slightly, although he retained that eager energy as he entered my room. His gaze swept over the sparse furnishings.

"They weren't joking about this place being remote. That helicopter flight was something else. Nothing but moor, mountains and trees, and they said the nearest proper road is hours away."

"That's right."

I took out my notebook, the one in which I had tracked patterns, recorded observations and tried to make sense of the impossible. Its pages were filled with notes about temperature drops, strange sounds and fence damage that had somehow disappeared by morning. I had reported the damaged section after the false hillwalker tried to enter, but never what had caused it. The way the damage seemed to repair itself remained a private observation.

None of those notes would help Owen. Experience was the only teacher at Black Crag.

I turned to a blank page and began to write. The rules came easily now, burnt into my memory by repetition and necessity.

1. Do not respond to any voice calling to you from outside the perimeter after dark, no matter who it claims to be.

Owen watched over my shoulder, curiosity plain on his face.

"What's that?"

"Standing survival orders for security duties and general conduct."

I kept writing, forming every letter clearly. There could be no room for misunderstanding.

2. Do not admit anyone who arrives at the perimeter on foot. No exceptions, regardless of apparent injury or claimed identity. Only personnel arriving by authorised helicopter or vehicle may enter, and only after verification.

"Perimeter security procedure," Owen said. "Seems fairly standard for a restricted installation."

I continued without answering.

3. If any animal speaks, do not acknowledge it and continue with assigned duties.

Owen laughed. It was a bright, genuine sound that bounced from the walls.

"Right. Now I know you're winding me up. Speaking animals? What is this, some new-starter initiation?"

"The Border Collie is the one people see most often," I said. "That doesn't mean it's the only one."

His smile widened, but I finished the final two rules in silence.

4. Lock your door before 00:00 every night and keep it shut until dawn. Do not open it for any reason.

5. If you hear screaming at night, do not investigate. If you are on duty, radio the operations room and remain at your post. If you are off duty, stay locked in your room.

I tore the page from the notebook and handed it to Owen. He accepted it with the same amused expression, reading the list as though it were a joke whose point he had not yet grasped.

"Come on, mate. Speaking animals and voices in the dark?"

He folded the paper and slipped it casually into his breast pocket.

"I understand. The new lad pays his dues. But between you and me, what's this place really like?"

I wanted to seize him by the shoulders and make him understand that every word on that paper could save his life. I wanted to tell him that I had heard my living mother's voice call to me from the darkness in the soft Geordie inflection I had known since childhood. That it had called me pet when it pretended to be frightened and recited a bedtime rhyme known only to the two of us, although my mother was safe in her flat in Newcastle upon Tyne.

I wanted to tell him that I had watched an injured hillwalker's face stretch and reform, its jaw extending too far, slate-grey hooked nails tearing at the fence while glossy black eyes with narrow vertical pupils fixed on me. That I had spent seventeen minutes paralysed while an eyeless visitor circled my bed and explained how it could steal my memories, my face and my identity.

Instead, I closed the zip on my kitbag.

"Follow the rules. They are standing survival orders, Price. Every one of them. That's all you need to know."

Owen's smile widened. He plainly thought I was committing fully to the wind-up.

"Follow the rules. Understood."

I shouldered my bag and looked around the room one last time. Six months of my life reduced to bare walls and standard furniture. Six months spent learning that the world contained things that should not exist, things that wore familiar faces and spoke with the voices of people we loved.

Owen followed me out, still talking about his training, his hometown and his excitement about the posting. It was the same eager confidence I had felt when I stepped off the Puma on 10 October, before I knew what waited in the dark and understood the exhaustion in Staff Sergeant Hargreaves's eyes.

We crossed the compound towards the marked military landing site. Owen asked about the rota, equipment maintenance and the quality of the food. Ordinary concerns for an ordinary posting.

I gave him basic answers, enough to satisfy him without repeating everything he had already dismissed. His first test might come that night in Watchtower Two, when the wind dropped and a voice called his name from beyond the fence.

The Puma appeared above the trees, its rotors beating through the cold air. I had never been so glad to hear that sound.

"Any advice?" Owen asked while we waited for it to land. "You know, from someone who's done the post to someone who's just starting it."

I looked at him properly and saw myself six months earlier: confident, sceptical and certain that training had prepared me for anything. Words alone could not easily penetrate that certainty, but I had to try.

"Keep that paper on you. Treat every rule as an order. Lock your door before midnight and keep it shut until dawn, no matter how tired you are and no matter what asks you to open it."

He laughed again, but something in my expression reached him. The sound faltered.

"It really matters to you lot, doesn't it? The whole rules business."

"You have no idea."

The Puma touched down, and a member of the aircrew signalled me forwards. I climbed aboard without looking back and settled into the webbed seat as the rotors gathered speed.

Through the window, I watched Owen shield his face from the rotor wash. He was already turning towards the accommodation block, his new home for the next six months.

Black Crag shrank below us as we gained height: four principal buildings within a fence that could not keep out the things that truly mattered, with watchtowers and aerials reaching into the sky. Twelve personnel remained inside the perimeter. Beyond it lay many miles of empty moorland, Scots pine, birch, forestry plantations and mountain ground where old things waited.

I understood why postings lasted only six months and why communication with the outside world was restricted. I understood why official reports never mentioned the real dangers.

Some truths could not be passed up the chain of command and analysed by people who had never heard their mother's voice calling from an empty forest. Some knowledge carried a price that could not be measured in pounds or personnel-hours.

The Puma banked south, carrying me back towards a world where animals did not speak and injured hillwalkers were merely injured hillwalkers. A world where locks protected property rather than memory and identity, and where screaming in the night meant somebody needed help.

Owen would face his first test soon, perhaps that night or perhaps the following week. He would hear something impossible and have to choose between his training, his compassion and five handwritten rules. Part of me hoped he would remember the urgency in my voice, that some instinct would make him pause before opening a door or answering a call from the dark.

But I knew how certainty worked. He would question and doubt. He would probably come close to dying before he learnt that the rules were not suggestions, initiation rites or regimental tradition.

They were the only defence between us and whatever waited in the darkness.

Black Crag disappeared behind the mountain ridges. I closed my eyes and tried not to imagine Owen alone in Watchtower Two, its searchlight sweeping the fence line as the wind suddenly fell silent and a familiar voice called his name.

He had the rules. That would have to be enough.

The Puma carried me south over moor, forest and mountain, towards roads, towns, crowds and ordinary human problems. Yet I knew I would never truly leave Black Crag behind.

Whenever I locked a door, I would check it three times. Whenever I heard an animal make an unusual sound, I would wait for words. Every scream in the night would make me freeze and count to five.

Some postings left you unchanged. Others left marks that never appeared on medical assessments or psychological reports, scars hidden where nobody could see them but you.

Six months at Black Crag had taught me that the world was stranger and more dangerous than I had imagined. It had taught me that survival could require ignoring every human instinct, and that there were things in the dark that knew our names and wore our memories like masks.

Owen would learn all of it, or he would not. In six months another authorised Puma would bring another replacement, and someone who had survived would hand over another list of five rules.

The cycle would continue. It had to.

Because somewhere among those mountain ridges, beyond the fence, beyond the rules and beyond the illusion of safety, things waited for someone to forget to lock their door.