The Voices Beneath Pen-y-Ffin

I stared at the framed photograph on my desk, the one Eleanor had insisted I display instead of leaving buried in storage. Four faces grinned back at me from the bonnet of Callum's battered van: Callum Price, Harriet Shaw, Mateo Ruiz and me, Tom Mercer. The Cairngorms, or perhaps the north-west Highlands, stretched behind us beneath a cloudless sky.

The locations blurred together after enough abandoned mines and ghost settlements. Seven years. It was hard to believe it had been that long since I had done anything more adventurous than walking the waymarked routes in the Peak District. Eleanor liked those weekend trips: predictable paths, clear signs and designated campsites.

Safe. Nothing like the places we used to find.

Our urban exploration group had begun simply enough. Callum and I met in our first year at Manchester Metropolitan University, bonding over a shared fascination with abandoned buildings. He had grown up sneaking into old warehouses. I just liked photographing decay and rust.

We made a good team. His boldness was balanced by my caution, though Callum would have called it paranoia. Harriet joined us in our third year, when she and Callum started going out.

Where he saw adventure, she saw stories. She spent hours researching each place before we visited, arriving with notebooks full of dates and names.

"Every abandoned place was someone's home," she would tell us, running her fingers along dusty windowsills. "Someone's whole life happened here."

Mateo joined us last. He was a postgraduate history student who overheard us planning a trip to an abandoned asylum. He appeared with Ordnance Survey maps and a folder of property records, explaining exactly which buildings were structurally sound and which approaches would keep us away from security patrols.

Callum rolled his eyes at first, but even he had to admit that Mateo's research kept us out of trouble more than once.

For three years, we explored everything we could find across northern England, Wales and the Scottish Borders. Abandoned hospitals with empty operating theatres. Factories where machinery stood frozen in mid-production. Hotels where guest registers still lay open on reception desks, names from decades past waiting to check out.

We documented everything. My photographs, Harriet's stories, Mateo's maps, Callum's videos.

Then Callum found the settlement.

He had been browsing an obscure urbex forum when he came across a single post, scarcely three lines long. Someone claimed to know of an intact mining settlement in the remote, exposed uplands of mid Wales, completely abandoned since the early 1960s. It gave one name, Pen-y-Ffin, a grid reference and coordinates, along with a warning that the access track appeared on no modern map.

"This is it," Callum said, his laptop open on my coffee table. "This is the one we've been looking for."

I was sceptical. Anonymous posts usually led nowhere, or worse, to places crawling with security guards or other explorers. But Mateo did what he always did, cross-referencing the coordinates with old survey maps, geological records and mining claims.

He found traces. Pen-y-Ffin had been a lead-and-zinc settlement in the Cambrian Mountains. Its records stopped abruptly in October 1961.

"No insolvency proceedings and no formal closure," Mateo explained, adjusting his glasses. "A settlement does not simply vanish from the records like this."

Harriet had been quiet throughout the planning, which should have been my first warning. She normally came alive during the historical research, but for this trip she merely nodded along. When I asked whether she was all right, she gave me a strange look.

"Do you ever think some places want to be forgotten?" she asked.

I did not know how to answer.

The overnight drive from Manchester took about six hours, lengthened by narrow mountain roads and wrong turns. We left on a Thursday night, taking turns behind the wheel of Callum's van while the others slept among our equipment: sleeping bags, camping stoves, enough food and water for a week, cameras, torches, head torches, first-aid supplies, rope and bolt cutters.

We had learnt to prepare for almost anything.

The coordinates led us past Shrewsbury and into increasingly empty country. By dawn, we were crossing peat-dark slopes broken by abandoned forestry, scree and low cloud. Signs warned of exposed military-training land beyond the road. Somewhere after sunrise, we turned from the tarmac onto an unmapped forestry track that my mobile phone insisted did not exist.

For nearly two hours we crawled deeper into the Cambrian Mountains. The track deteriorated into twin muddy ruts. Twice we had to get out and walk ahead to make sure the van would not slide into a concealed ditch or off a crumbling edge.

Then we crested a rise and saw Pen-y-Ffin.

The settlement occupied a natural bowl between rust-coloured hills. Perhaps thirty buildings clustered around what had once been the high street. Even from a distance, I could see the chapel steeple leaning at an impossible angle, like a finger pointing accusingly at the low grey sky.

"Christ," Callum breathed. "It's perfect."

Perfect was not the word I would have chosen. Preserved, perhaps. Waiting.

We descended slowly, the van engine sounding far too loud in the morning stillness. The buildings grew larger as we approached: two-storey structures with false fronts intended to make them appear grander, miners' cottages with roofs half-collapsed, and what might once have been the village shop, its windows dark and empty.

Callum parked outside the largest building, a three-storey former coaching hotel with HOTEL still visible in faded paint above the entrance. We sat there for a moment without moving.

"Well," Mateo said at last. "We're here."

The silence outside was complete.

No birds. No insects. No wind. Only our boots pressing into wet grit and the soft ground of a place that looked as though rain should never leave it. The pale morning light formed pools of darkness between the buildings, shadows that seemed too deep for the hour.

"Let's establish a base first," I suggested, lifting my camera bag from the van. "We can check the hotel and see whether it's stable enough to sleep in."

The front door hung open, revealing a lobby thick with dust. Our torch beams cut through the gloom, illuminating a reception desk with its register still in place. Chairs stood arranged as though waiting for guests who would never arrive. A staircase curved upwards into darkness.

"Looks solid," Callum announced after inspecting the main beams. "Better than sleeping outside."

We carried our equipment into a large ground-floor room that might once have been a dining room. The tables were gone, but marks in the floor showed where they had stood. Harriet spread her sleeping bag in one corner while Mateo immediately began sketching the settlement's layout.

I could not shake the need to document everything at once, as if the place might disappear whenever we looked away.

While the others arranged the camp, I wandered through the hotel with my camera. Guest-room doors stood open on the first floor. Beds remained made beneath quilts grey with dust. In one room, clothes still hung in the wardrobe: a woman's dress, a man's work clothes and a child's shoes lined up neatly underneath.

The second floor felt different. It was colder, despite the mildness outside. Its corridor extended farther than seemed possible within the building's dimensions. Doors stood open on identical rooms.

At the far end, one door remained closed.

I reached for its handle, then stopped. Something about that door made me want to leave it undisturbed.

Downstairs, I found the others examining a stack of newspapers Mateo had discovered behind the reception desk. They were copies of The Radnor Gazette, dated throughout 1961. The headlines became stranger as the dates advanced.

"THIRD FAMILY DISAPPEARS WITHOUT TRACE," Harriet read. "POLICE SEEK FRESH WITNESSES."

Mateo lifted another edition. "MINE FOREMAN REPORTS VOICES IN LOWER WORKINGS. COMPANY DENIES SAFETY CONCERNS."

The final newspaper was dated 15 October 1961. Its headline asked only:

"WHERE IS EVERYONE?"

"That is deeply unsettling," I said, photographing the front page.

Callum laughed, but the sound was forced in the empty lobby.

"Come on. It was probably economic collapse. The mine ran out. People moved away. It happens."

"Leaving everything behind?" Harriet asked. "Even their clothes?"

"Perhaps they were in a hurry." Callum shrugged, though I caught him looking towards the stairs. "We wanted authentic. We got authentic. This is what we came for."

We spent the remainder of the day exploring in pairs. Callum and Harriet took the eastern part of Pen-y-Ffin while Mateo and I went west.

Every building told the same story: lives interrupted, possessions abandoned and dust settling over scenes that felt staged rather than inhabited.

The chapel was the worst. Hymn books remained open on the pews at "Nearer, My God, to Thee". Children's drawings covered one wall: crayon pictures of families, houses and something else. Dark shapes with too many angles, painful to look at directly.

"Perhaps there was a mining accident," Mateo suggested as he studied them. "Trauma expressed through the children's art."

I photographed everything, trying to capture whatever felt wrong. In the afternoon light, shadows fell in directions that did not correspond with the sun. Doorways appeared to lead farther into buildings than their dimensions allowed. Beneath it all was the sensation of being watched, making me glance repeatedly over my shoulder.

By evening, we had regrouped at the hotel. Callum had found the mine entrance at Pen-y-Ffin's northern edge, although a partial collapse prevented exploration. Harriet had discovered the village school, with lessons still written on its blackboard. The arithmetic did not quite add up.

We prepared dehydrated stew on our camping stoves. Its smell seemed peculiar in the dusty hotel. As darkness approached, we went outside to escape the oppressive atmosphere and set chairs around a brazier Callum had made from a rusted oil drum in the high street.

"To the discovery of a lifetime," he said, raising a bottle of ale.

We clinked bottles, but the toast felt hollow.

The cloud had thinned by then. Stars emerged above the black outlines of the buildings and I set up my tripod for several long exposures, using the crooked chapel steeple as a foreground.

"I don't like it here," Harriet said suddenly.

We all turned. She was hunched in her chair, her arms wrapped around herself despite the warmth of the brazier.

"What do you mean?" Callum asked.

"Can't you feel it? As if we're being watched? As if Pen-y-Ffin doesn't want us here?"

Mateo nodded slowly. "I have felt it too. It may simply be the isolation and the silence. Our minds are not accustomed to this degree of quiet."

"It isn't only that." Harriet stared into the fire. "When I was in the school, I could have sworn I heard... I don't know. Whispering. Like children talking in the next room, except there was no next room."

"It could have been air moving through the boards," I offered, although I had noticed the complete absence of wind throughout the day.

"Yes. Maybe." She did not sound convinced.

Callum reached across and squeezed her shoulder. "We've explored dozens of places. They all feel strange at first. By tomorrow, this will be another dead settlement with a sad story."

I wanted to agree. This was what we did. We found places forgotten by time, documented them and shared their stories.

But Pen-y-Ffin felt different. The abandonment was too complete and too sudden. There was something else as well, something I could not name.

We remained beside the brazier until the cold drove us indoors. In the hotel, we laid out our sleeping bags in the dining room. Nobody suggested separating into the guest rooms. Callum and Harriet curled together near one wall. Mateo chose a corner from which he could see both entrances, and I settled near the windows.

"First one awake makes coffee," Callum called as we bedded down.

"Agreed," I replied, although I doubted I would sleep.

The hotel creaked as the temperature fell, contracting timbers producing sharp cracks that made all of us jump. Our torches created a small island of light within the vast darkness. Outside, the abandoned settlement waited.

I lay awake for hours, listening as the others' breathing gradually deepened into sleep. Every noise seemed amplified: Mateo's occasional snore, Harriet murmuring something unintelligible, the rustle of sleeping bags when somebody shifted.

Then, at 03:26, I heard crying.

It was distant and muffled, like someone weeping behind closed doors. I sat upright and strained to locate it.

The sound seemed to come from above. Perhaps the first floor, perhaps farther away. It rose and fell, profoundly human in its grief. I gripped my torch but did not switch it on.

The crying continued. Words joined it, though I could not make them out.

My rational mind supplied explanations: air moving through broken windows, animals, the acoustic tricks of an empty building. My instincts knew better.

The sound gradually faded, leaving me wide awake and painfully alert. I wanted to wake the others, but what would I say? That I had heard someone crying in an abandoned hotel? They would think Harriet's unease had infected me.

I lay down again, keeping the torch in my hand. The hotel settled into silence, but now it felt expectant rather than empty.

Whatever had made that sound, I was certain of one thing. We were not as alone as we had believed.

The rest of the night crawled past. I dozed fitfully, jerking awake at every creak and crack. When pale light finally filtered through the dusty windows, I had never been so grateful for dawn.

Mateo woke me by shaking my shoulder. His face looked exhausted. The thin light coming through the hotel's filthy windows suggested it was only just past sunrise. My back ached from the hard floor and my mouth tasted as though I had been chewing the dust coating the room.

"Coffee," Mateo croaked, gesturing towards the camping stove he had set up beside our equipment.

I sat up. Harriet and Callum remained tangled together in their sleeping bags. She had eventually fallen asleep perhaps an hour earlier, after spending most of the night shifting restlessly. The crying I had heard at 03:26 continued to repeat in my head, though I had not told anyone about it.

While the water heated, I went outside to stretch.

Pen-y-Ffin looked different in the early light, less threatening and more melancholy. The tilted chapel steeple caught the first watery brightness. For a moment, I could almost imagine the settlement alive: miners walking to their shifts, children playing in the muddy street.

Mateo joined me with two cups of instant coffee. It tasted like burnt rubber but felt like salvation.

"Did you sleep?" I asked.

He shrugged. "Some. I kept thinking I could hear things."

"What sort of things?"

"Nothing specific. Just sounds that shouldn't have been there." He adjusted his glasses, a nervous habit I had noticed over the years. "This place has dreadful acoustics. Sound carries strangely in the hills."

I nodded, though both of us knew that was not quite the truth.

The silence was unnatural. Too complete, as if Pen-y-Ffin existed inside a sealed pocket, separate from the rest of the world.

By the time Callum and Harriet emerged, the daylight had strengthened and the morning chill had begun to ease. Harriet was pale, with dark crescents under her eyes that made her appear fragile. She managed a faint smile when I handed her coffee, but her hands trembled as she curled them around the cup.

"Right, team," Callum announced, stretching theatrically. "Day two in paradise. I think we should split up and cover more ground. Tom, you and Mateo take the administrative buildings - the council offices, perhaps a bank if they had one. Harriet and I will inspect the residential area and see what stories the houses have to tell."

Harriet's face tightened, but she did not object.

I wanted to suggest that we remain together, but Callum was already checking the batteries in his camera. That focused energy meant he had made up his mind.

Mateo had sketched a rough map based on the previous day's exploration, marking each building according to its probable purpose. The administrative quarter clustered around what might once have been a small central square, although any fountain or memorial had long since collapsed into rubble.

"Meet back here for lunch," Callum suggested. "At 13:00."

We agreed, though something in Harriet's expression made me want to alter the arrangement. Before I could speak, she followed Callum towards the residential streets, her camera bag over one shoulder.

Mateo and I went in the opposite direction, our footsteps unnaturally loud in the morning quiet.

The first building we entered had probably contained the council offices. It was a two-storey structure with tall windows and the remains of official-looking furniture. Desks stood in orderly rows in the main room, papers still stacked upon several of them.

"Look at this," Mateo called from behind one desk.

He held up a ledger, its pages yellow and brittle.

"Rates and local accounts, I think. They continue all the way to October 1961."

I photographed him holding the book, then took close-ups of the pages, capturing names and sums written in fading ink. It was the mundane business of a settlement that did not know it was about to die.

The upper floor contained offices, each a frozen image of interrupted work. In what must have been the clerk's room, a calendar still displayed October 1961. Somebody had crossed off the days up to the 14th.

The 15th, the date of the final newspaper, remained unmarked.

"Tom."

Mateo's voice came from farther along the corridor, tightened by something I could not identify.

I found him in a small room at the back of the building, staring at the wall behind an overturned desk. Words had been carved deeply into the plaster in uneven, desperate letters:

THEY COME FROM BELOW. THE CHILDREN HEAR THEM FIRST. GOD HELP US ALL.

Beneath them, scratched in what appeared to be a different hand, was another warning:

DON'T LET THEM TAKE YOU DOWN.

"A mining accident," Mateo said, although his usual academic certainty had deserted him. "It must have involved gas. Hallucinations, perhaps."

I photographed the wall from several angles, trying to capture the raw terror in the carved words. The room felt colder than the others. Without intending to, I found myself retreating towards the door.

We spent the rest of the morning documenting Pen-y-Ffin's administrative buildings. The bank vault stood open, with pre-decimal notes and coins still in its drawers - another indication of how quickly everybody had left.

Or been taken, a voice whispered in my mind.

I forced the thought away.

The post office was stranger still. Letters remained sorted in pigeonholes, waiting to be delivered. I removed several and felt like a grave robber.

Most were ordinary: bills, personal correspondence and a Littlewoods catalogue. But an envelope addressed to someone in Shrewsbury had been opened and resealed. Inside was a single sheet of paper bearing one line:

IF YOU'RE READING THIS, DON'T COME LOOKING FOR US.

By the time we returned to the hotel for lunch, weak sunshine had broken through the cloud. Mateo and I compared notes as we walked, attempting to construct a timeline from the documents we had discovered. Everything suggested a gradual escalation through September and early October, followed by abrupt silence.

Harriet and Callum were already at the hotel. Harriet sat on the front steps with her knees drawn to her chest while Callum paced in front of her.

"Are you all right?" I asked, sitting beside her.

She looked at me. Her green eyes, normally bright with curiosity, appeared haunted.

"I heard them again."

"Heard what?"

"Children laughing." Her voice was scarcely above a whisper. "We were inside this perfectly preserved cottage. Toys were still on the floor, as though the children had only just left. Then I heard them, Tom. Clear as anything. Children playing in the next room."

Callum stopped pacing. "I checked every room. There was nothing there."

"I know what I heard." Harriet's jaw set in the stubborn way I recognised. "It wasn't wind. It wasn't the building settling. It was children."

Mateo sat on her other side. "The mind can deceive us in places like this. Pareidolia - perceiving meaningful patterns where none exist. It can happen with sound as well as images."

Harriet shook her head but did not argue further.

We ate lunch in relative silence, each of us lost in private thoughts. The sandwiches tasted like cardboard. Even Callum's usual enthusiasm seemed diminished.

Afterwards, we decided to inspect the mine entrance together.

The walk to the northern edge of Pen-y-Ffin took us past more abandoned houses, their empty windows watching us pass. The ground opened as we climbed a shallow rise, revealing a scarred hillside where mining had carved into the earth.

The main entrance was exactly as Callum had described it: a timber-framed opening partially blocked by fallen rock. Rails emerged from the darkness and vanished into the collapse roughly 6 metres inside. Faded warning notices remained legible in three languages.

"Typical arrangement for the period," Mateo explained as he examined the entrance. "There would have been several levels descending along the ore veins. They may also have connected with natural cave systems."

I took photographs, careful not to approach the unstable rocks. The darkness beyond the collapse seemed absolute, swallowing our torchlight whenever we attempted to peer farther inside.

"Do you think we could clear some of these?" Callum asked, already reaching for a smaller stone.

"Don't." Harriet's voice was sharp. "Please, just don't."

Callum withdrew his hand and frowned. "It's only rock, Hattie."

"No, it isn't." She stared at the mine entrance as if it might swallow us whole. "Can't you feel it? Something is wrong here. More wrong than the rest of Pen-y-Ffin."

I felt it as well, although I could not have explained it. The entrance radiated wrongness, like an optical illusion that refused to resolve. The air around it felt heavier and colder despite the daylight.

"Mining disasters were common," Mateo said, though he had retreated several steps. "Especially in operations of this scale. Collapses, gas pockets, underground water. Any number of things might have gone wrong."

"All at once?" Harriet challenged him. "The whole settlement abandoned because of one accident?"

"Perhaps it was particularly severe," Callum suggested, though even he seemed subdued by the oppressive presence of the mine. "Perhaps they broke into something they shouldn't have."

The words hung in the air, uncomfortably close to my own thoughts.

We remained there for several minutes. Nobody wanted to approach the entrance, yet none of us seemed willing to leave. At last, Harriet turned and began walking back towards the settlement. The rest of us followed, although Callum looked over his shoulder at the mine one final time.

The afternoon passed quietly. We explored several more buildings together, but the energy had left our investigation. Every shadow appeared deeper and every empty room more oppressive. Even Callum's jokes fell flat.

As evening approached, we collected wood for another fire. The simple task was reassuring, something ordinary in a place that was anything but.

We had only just lit the brazier when the chapel bell sounded.

Four clear strokes rang across the abandoned settlement.

We froze. I watched the crooked steeple above the rooftops but saw no movement.

After a pause, the bell sounded four more times, then fell silent.

"Wind?" Mateo suggested weakly.

"There is no wind," Harriet whispered.

She was right. The air was perfectly still and the brazier's smoke rose in a straight column.

I had photographed the bell the previous day. Its mechanism was rusted solid and its rope had rotted away. There was no possible way for it to ring.

But it had.

"All right," I said, surprised by the steadiness of my voice. "I think we should consider leaving tomorrow. We've documented enough."

"One more day," Callum interrupted. "Only one. We need to inspect the chapel properly, and there may be more to find around the mine."

"Callum," Harriet began.

"One day," he insisted. "We drove through the night to get here. We can't leave without exploring it properly. When will we ever find another place like this?"

I wanted to argue, but I knew that expression. Once Callum entered this stubborn state, he was immovable. Part of me - the part that had spent years searching for abandoned places - wanted to know what was inside that chapel as well.

"Fine," I said. "But tomorrow we stay together. No splitting up."

"Agreed," Callum replied quickly, probably recognising the best compromise he was likely to receive.

We went inside as darkness fell and arranged our sleeping bags in the same positions as the night before. Nobody proposed using the guest rooms. The hotel felt even less welcoming. Its shadows seemed deeper and its silence more oppressive.

Mateo volunteered to keep the first watch.

"I'm not tired anyway," he said, although the dark crescents beneath his eyes suggested otherwise.

I lay in my sleeping bag with my camera beside me, listening as the others settled. Callum and Harriet whispered to one another, too quietly for me to distinguish the words. Eventually, their breathing deepened.

That was when the walkie-talkies began.

We had brought them for emergency communication and left them switched on in case we became separated. They lay in a pile with the rest of our equipment, all tuned to the same channel with the volume low.

Static came first, rising and falling in waves.

Then, beneath it, came voices.

They were not clear enough to understand, but they were unmistakably human. Several people were speaking, their words buried within the electronic hiss.

Mateo was already moving towards the radios when I sat up. He picked up one unit and adjusted the squelch, trying to clean the signal.

The voices became clearer but no more comprehensible. Sometimes they spoke in unison. Then they separated into what sounded like a conversation.

The language was wrong. Not foreign, exactly, but distorted, like English played backwards and forwards at the same time.

"Radio interference," Mateo muttered, but his hands shook as he tried another channel.

The voices followed him. They grew louder.

I seized another walkie-talkie and switched it off. The voices continued through the remaining units. Mateo and I stared at one another, then hurriedly shut down every radio.

Silence returned.

"Atmospheric conditions," Mateo said. "Signals bouncing from somewhere else. Mountainous country can play havoc with radio waves."

I nodded, believing him no more than he believed himself.

We sat in the darkness. Neither of us suggested attempting to sleep. Somewhere within the hotel, timber creaked. Outside, Pen-y-Ffin waited.

Hours passed. Mateo and I took turns dozing, ensuring that one of us remained awake and alert. The hotel's noises seemed louder in the darkness: settling wood, a faint whisper through broken windows and, beneath everything, something that might have been breathing.

It was probably our imagination.

Sometime after midnight, the sounds began. They did not come from one direction but from several, as if the settlement itself were sighing. Low, mournful notes moved through the buildings. They might have been air passing through empty rooms, yet they sounded far too much like voices.

They rose and fell, almost becoming words but remaining just beyond understanding.

Harriet woke and sat upright.

"Can you hear that?"

"Only the buildings," Callum mumbled, still half asleep. "Old timber. Temperature changes."

Harriet was already crying. Silent tears ran down her cheeks.

I moved closer, unsure what comfort I could offer. The sounds surrounded us, as though the whole settlement were mourning something lost long ago.

"It's so sad," Harriet whispered. "Whatever happened here, they're still sad about it."

I wanted to tell her it was only noise, merely the natural sounds of an old, empty place. But as I sat in the darkness listening to those grief-stricken voices, I could not force myself to lie.

Mateo maintained his watch, his face grim in the glow of his torch. Callum held Harriet and whispered reassurances that sounded hollow. I sat with my camera beside me, wondering what we had found and whether Callum's insistence upon one more day would become something we all regretted.

The sounds continued until dawn, rising and falling like a tide of grief. When the first light crept through the windows, we were all awake, exhausted and deeply troubled.

One more day, I told myself.

Only one more day, and then we could leave Pen-y-Ffin to its ghosts.

But when I looked at my friends' drawn faces, I wondered whether one more day might be one too many.

Morning brought dense hill mist. It pressed against the hotel windows like something alive, reducing visibility to roughly 6 metres. I stood on the front steps with my camera, trying to capture the way it transformed the abandoned buildings into vague, hulking shapes.

The mist muffled sound even further, producing a silence so complete that I felt pressure inside my ears.

The others were finishing breakfast indoors. The instant porridge tasted like cardboard but at least filled our stomachs. Callum had been unusually quiet since waking, studying Mateo's hand-drawn map with an intensity that made me nervous.

He had already ventured out once that morning, returning with damp hair and an excited gleam in his eyes that I recognised from previous discoveries.

"I found something interesting," he announced, tapping one section of the map. "There is a house on the eastern edge, set apart from the others. Mateo, you haven't marked any cellar entrance."

Mateo leant over the map and adjusted his glasses. "I recorded only what I could see from outside. Some of the foundations have shifted so much that -"

"This one is different," Callum interrupted, already packing his equipment. "The foundation is actually sinking into the ground. It looks as though the whole house is being swallowed. But here's the interesting part. I saw hinges. Metal hinges fixed to what should be a solid foundation."

Harriet set down her coffee cup harder than necessary. "We agreed to inspect the chapel today. Together."

"We will. This won't take long." Callum was already approaching the door. "I only want to see what's underneath."

I caught Harriet's expression, a mixture of fear and resignation I had seen too many times. She knew that arguing with Callum when he was in exploration mode was pointless.

Mateo folded his map and prepared to follow. After a moment, Harriet picked up her jacket.

The mist made navigation difficult. We moved slowly through Pen-y-Ffin's streets, using the tilted chapel steeple as a landmark whenever it emerged through a gap in the whiteness.

The houses at the eastern edge stood farther apart, as if their builders had wanted distance from their neighbours - or from something else.

Callum's discovery stood alone at the boundary, where the settlement yielded to peat, scree and abandoned forestry. The house itself was unremarkable: a single-storey timber-framed cottage typical of a Welsh mining community.

But Callum was right about its foundation.

The entire building leaned to one side, its base vanishing into earth that appeared disturbed, almost churned.

"A sinkhole," Mateo suggested, although his voice lacked conviction.

"Look at the angle," Callum said, already circling the cottage. "And here. Do you see?"

He pointed to what I had initially mistaken for decoration among the foundation stones. Metal hinges, green with age but still solid, were attached to a section of the foundation itself. The edges were too regular to be natural and too deliberate to be accidental.

"It's a door," I said, lifting my camera. "Built into the foundation."

"Hidden," Harriet corrected from well behind us. "Hidden for a reason."

Callum had already taken out his pry bar. The door possessed no visible handle or lock, only those hinges and a barely discernible seam between the stones. He forced the bar into the gap and put his weight against it.

"Perhaps we should think about this first," Mateo suggested. "Document it and research the structure."

The door sprang open with a grinding noise that made all of us recoil.

Cold, stale air rushed out, carrying the smell of wet copper. Beyond the opening, wooden steps descended into darkness.

"A cellar," Callum said, though even he sounded uncertain.

The steps were wrong. They were too steep and too narrow, descending much farther than an ordinary cellar required. I directed my torch into the opening. For roughly the first metre the walls were stone, after which they became packed earth braced with wooden beams. The construction differed from the rest of Pen-y-Ffin. Despite the age-blackened timber, it seemed newer.

"Those bolts," Harriet said, pointing to the inner face of the door.

Heavy iron fixtures had been fitted there, several of them, designed to secure the door from within.

"Somebody wanted to keep people out," I said.

"Or keep something in," Mateo finished.

Callum was already descending, his head torch cutting into the darkness.

I followed, partly to document whatever we discovered, but mostly because I did not want him going alone. The steps creaked beneath our weight but held.

Behind me, I heard Mateo trying to persuade Harriet to remain outside. Then his footsteps followed us down. A moment later, so did hers.

The staircase ended in a small chamber roughly 3 metres square. Newer timbers reinforced its walls, resembling the supports in a mine shaft.

But this was not the mine.

The floor was packed earth except in one corner, where somebody had installed a metal grate.

"A storage cellar," I suggested as I photographed the room.

Callum was already inspecting the grate.

"No. Look at this."

The metal covered an opening roughly 1 metre square. Darkness lay beneath it, deeper than our torch beams could penetrate. That was not what made my skin crawl.

Three padlocks secured the grate. They were modern and appeared no more than fifteen years old.

Somebody had visited Pen-y-Ffin long after it was abandoned.

"We need to see what's beneath it," Callum said, already applying his tools to the locks.

"Callum, stop." Mateo's voice was sharp. "This isn't like the other buildings. Somebody went to considerable effort to seal this opening."

"Exactly why we need to look."

The first lock snapped open.

"This is what we came for. Real mysteries, not merely empty houses."

I wanted to agree with Mateo, but curiosity overcame caution. Whatever was down there, somebody had considered it important enough to secure decades after Pen-y-Ffin died.

The second lock fell away, then the third.

Callum lifted the grate, revealing rough stone walls descending into blackness.

"It's a tunnel," he breathed.

It was more than a simple tunnel. A passage cut through solid rock sloped sharply downwards. Crude tool marks scarred the walls, as though it had been excavated in haste or desperation. Wooden supports stood every few metres. Some appeared original; others had plainly been added later.

"A mining tunnel," Mateo suggested, though he sounded unconvinced.

"Wrong direction," Callum said, already lowering his legs through the opening. "The mine is north of here. This passage runs east, towards nothing."

Harriet had come fully into the chamber despite Mateo's warning. Her face looked colourless in the beams of our head torches.

"There is nothing out there but open upland," she said.

"Only one way to find out." Callum dropped into the passage and landed with a thud. "Solid ground. Come on."

I looked at Mateo. He gave a resigned shrug. We had already come this far.

I lowered myself through the opening, protecting my camera bag. The tunnel was only just high enough to stand in and scarcely wide enough for one person. Mateo descended next, then helped Harriet down despite her obvious reluctance.

The passage sloped more steeply than I had expected. Our head torches made a small bubble of light, rendering the darkness ahead even more absolute. Rough walls caught at our clothes as we moved. At intervals of roughly 6 metres, timber supports groaned beneath the weight of the earth above.

"This isn't safe," Mateo muttered as he inspected a badly warped beam.

"It has held for this long," Callum called from nearly 9 metres ahead.

The temperature dropped as we descended. My breath began to mist in the beam of my head torch. The smell changed as well: less dust, more mineral, with an organic undertone I could not identify.

Sulphur, perhaps, though that made no sense there.

We had descended roughly 400 metres when the first sound reached us.

It was distant and muffled, yet unmistakably deliberate: a wail rising and falling in patterns too regular to be natural.

Harriet seized my arm.

"We need to go back. Now."

"It's only moving air," Callum said, though he had stopped walking. "Pressure differences in the tunnel system."

"That isn't wind," Harriet insisted. "Listen to it. Those are voices."

She was right.

The wailing had a quality that suggested words, though they belonged to no language I recognised. It came from ahead, from deeper within the tunnel, rising and falling like a conversation or argument conducted through inhuman throats.

"We're going back," Mateo decided. "This is beyond anything we're equipped for."

"Five more minutes," Callum bargained. "Just to see what's making that sound. Then we leave."

"Callum," I began.

"Five minutes," he repeated, already moving forwards. "We've come this far."

I followed, hating myself for it. Behind me, Mateo swore, but kept pace. Harriet's breathing had become shallow with fear, yet she stayed with us.

The tunnel continued downwards, and the wailing grew louder without becoming any clearer. If anything, the sounds became more distorted as we approached, as though whatever produced them had not been made for human ears to understand. The sulphurous smell intensified. Even in the cold, it made my eyes water.

The timber supports showed greater damage here. Some had cracked almost completely through, while others bulged inwards as though the earth were trying to reclaim the passage.

"Look at this." Callum's voice came from ahead, tight with either excitement or fear.

The tunnel opened into a broader space. It was not quite a chamber, but rather a natural cavity into which someone had broken. Our torch beams passed over walls that had not been carved but formed, their smooth curves and mineral deposits belonging to a natural cave system.

That was not what stopped us.

The far wall was covered in writing. It had not been scratched into the stone like the desperate message in the council offices, but painted in something dark that had endured for decades. The symbols were not Welsh or English, nor anything else I recognised. Their angles seemed to shift when I tried to focus upon them. Looking directly at them hurt, as though my mind could not process their shape.

"What is that?" Mateo whispered.

Before anyone could answer, the wailing ceased.

The silence struck with such force that my ears rang. Then, from somewhere deeper in the cave system, came another sound.

Footsteps.

Slow and deliberate, drawing closer.

"Out," Harriet said. "Out now."

For once, Callum did not argue. We turned together and hurried back towards the tunnel entrance.

We had covered only a few yards when the first timber support cracked. It happened in an instant. The wood splintered with a report like a gunshot. Earth trickled from above, then began to pour.

The tunnel shook. A deep rumble passed through my chest.

"Run!" Mateo shouted.

We ran.

Behind us, more supports failed in sequence, every sharp crack followed by the thunder of falling earth. The beam of my head torch bounced wildly as I sprinted, offering fractured glimpses of tunnel walls and the backs of the others. Harriet was ahead of me, Mateo behind. Callum led, as he always did.

Another support failed directly above me. I flung myself forwards as timber, stone and earth crashed down where I had been standing. Dust filled the passage, reducing the world to less than a metre of choking grey. The rumbling became louder. It no longer came solely from behind us, but from every direction, as though the entire tunnel system were collapsing.

"Keep moving!" Callum's voice was scarcely audible above the destruction.

I stumbled, caught myself and ran on. Dust and exertion scorched my lungs.

Somewhere behind us, the inhuman wailing began again, as though the collapse had awakened whatever made it.

Then it happened.

The section of tunnel ahead of Callum gave way all at once. There was no warning, no gradual failure. One moment he was running. The next he had vanished beneath tonnes of earth and stone.

"Callum!"

Harriet's scream cut through the rumbling.

I skidded to a halt just short of the collapse. Where Callum had been, there was now a wall of shifting debris. Through the dust, I could make out a gap near the floor, perhaps half a metre high.

Something moved within it.

"Help me."

Callum's voice was muffled and desperate.

"I can't move my legs."

I dropped to my knees and clawed at the debris. Stones came away in my hands, but others shifted immediately into their place. Through the gap I could see Callum's face, contorted by pain and terror. Blood ran from a gash across his forehead.

"My legs," he gasped. "Something's on my legs. Get it off."

Mateo was beside me now, and we dug frantically together. For every stone we removed, the pile settled further, threatening to close the gap entirely.

Behind us, more of the tunnel was failing. The wailing had risen into screams, much closer now, as though whatever produced them were racing the collapse towards us.

"We have to go," Mateo said, gripping my shoulder. "The whole thing's coming down."

"We can't leave him."

I tore myself free and reached through the gap. Callum's hand found mine and closed around it with desperate strength.

"Please," he begged. "Don't leave me here. Please."

As my eyes adjusted, I saw more. The rocks had not merely pinned his legs. They had crushed them. Blood pooled around his lower body. Far too much blood. Even if we could have shifted the debris, I did not know whether he would survive.

"Tom." Mateo's voice was urgent. "We have to go now."

Another section of tunnel collapsed behind us.

Harriet was sobbing as she dragged at the stones with bleeding fingers. The gap narrowed while the debris settled. Callum's grip weakened around my hand.

"I'm sorry," I said. The words tore themselves from my throat. "I'm so sorry."

"Don't," Callum whispered. "Don't leave me. Not here. Not with them."

The wailing was almost upon us.

In the darkness beyond the collapse, something moved. Its shape was not quite right. Neither was its size.

Callum saw it too. His eyes widened, and he screamed, not from pain but from absolute terror.

Mateo seized me and pulled with all his strength. This time I let go of Callum's hand. I allowed Mateo to drag me away as the gap closed and cut off Callum's screams.

We ran, with Harriet between us, while the tunnel died behind us.

The collapse pursued us, always only a few yards back, bringing darkness and that dreadful wailing with it. Among the inhuman voices, I thought I could hear Callum screaming.

We reached the roughly 3-metre vertical shaft as the final supports began to fail. Mateo boosted Harriet upwards, then me. I hauled myself out of the tunnel as the rumbling reached a crescendo.

Mateo's hands appeared over the edge. I caught them and pulled with strength I had not known I possessed. He came up just as the tunnel mouth collapsed completely, blasting dust and the stench of sulphur into the cellar.

We lay on the floor, gasping, coated in dirt and Callum's blood. Beneath us, the rumbling continued for several long seconds before fading.

Then there was silence, broken only by Harriet's hysterical sobbing.

Callum was gone, buried under tonnes of rock in a tunnel that should never have existed, beneath a settlement that wanted to be forgotten. As I lay there trying to comprehend what had happened, I could still hear those inhuman wails echoing up from the depths, carrying Callum's screams with them into the darkness.

I stumbled out of the cellar, my legs scarcely supporting me.

The hill mist had lifted while we were underground. Hard afternoon sunlight now fell across the wet, peat-dark slopes and made me squint. Harriet collapsed on the dead grass beside the house. Her entire body shook with sobs that came from somewhere deep and broken.

Mateo stood motionless at the cellar entrance, staring down at the sealed shaft as if he might will it open again.

My hands were torn and bleeding from digging at the rocks. Callum's blood had mixed with the dirt beneath my fingernails, forming dark crescents I could not stop looking at. The image of his terrified face through the gap replayed endlessly, especially the moment he realised we meant to leave him.

"We need help," Mateo said. His voice was flat and mechanical. "Emergency services. Cave rescue."

I took out my mobile phone with shaking fingers. There was no signal. Of course there was not. We were in the remote uplands of mid Wales, in a settlement that did not officially exist.

I tried anyway, walking in circles and holding the phone above my head, desperate for a single bar.

"Nothing," I said.

Harriet's sobs had subsided into ragged breathing. She sat up, tears cutting tracks through the dirt on her face.

"We have to go back down. We have to try again."

"Harriet," Mateo began.

"We can't leave him."

She was already on her feet and moving towards the cellar.

"He's still down there. What if he's still..."

"He's not," I said, hating the sound of the words. "You saw how much blood there was."

"You don't know that."

She spun towards me, her eyes wild.

"You let go of his hand. You left him."

The accusation struck like a physical blow because she was right. I had let go. I had chosen to save myself while Callum screamed for help.

"The tunnel was collapsing," Mateo said quietly. "We would all have died."

"Then we should have." Harriet's voice cracked. "We should have stayed with him."

I wanted to argue, to defend myself, but no words came. Instead, I looked at the house and the disturbed ground surrounding its foundations. Whatever we had found below, whatever had produced those sounds, it felt as though Pen-y-Ffin itself had swallowed Callum whole.

"The nearest sizeable town is Llandrindod Wells," Mateo said, unfolding his map with unsteady hands. "About 50 kilometres away. They'll have emergency services and proper equipment."

Harriet was already heading back into the cellar.

I caught her at the entrance and grabbed her arm as she began descending the steps.

"Harriet, wait. We need to be sensible about this."

"Sensible?"

Her laugh sounded more like another sob.

"We were never sensible. We came to this place. We opened that door. We went down that tunnel. And now Callum is..."

She could not finish.

"Let me go back down," I said. "Just me, to check."

Mateo appeared beside us.

"Not alone. We stay together."

We descended the cellar steps again, moving slowly this time.

The small chamber looked exactly as we had left it: the open grate, our tracks through the dust. But when I directed my torch into the shaft, my heart sank. The tunnel entrance was completely blocked. It was not merely collapsed as before, but sealed by debris packed so tightly that it resembled solid stone.

"Callum!" Harriet screamed into the shaft. "Callum, can you hear me?"

Only silence answered.

We tried regardless. We found lengths of timber in the house and attempted to shore up the edges of the shaft. Mateo and I took turns climbing down and digging at the blockage, but every stone we removed caused others to shift. After an hour, we had scarcely made an impression.

"It's getting worse," Mateo said after his third attempt. "The whole chamber is unstable. If we keep digging, we'll bring the rest of it down."

I made one final descent and pressed my face against the debris, listening for any sound.

There was nothing. No wailing, no footsteps, no Callum. Only the occasional groan of settling earth.

When I climbed back up, Harriet was sitting against the wall, staring at nothing.

"He's gone, isn't he?"

I could not speak. I merely nodded.

"We need to get help," Mateo said. "Real help. Recovery equipment. People who know what they're doing."

The walk back to the former coaching hotel felt like a funeral procession.

We packed in silence, throwing everything into the van without any attempt at organisation. Harriet sat in the back with Callum's camera bag clutched to her chest. I drove, my bloodied hands shaking on the steering wheel.

The 50 kilometres to Llandrindod Wells seemed endless. Peat-dark slopes, abandoned forestry, scree and stretches of exposed military-training land blurred past beneath low cloud, but all I could see was Callum's face within that gap and the terror in his eyes when he saw whatever had approached through the darkness behind him.

What had he seen? What had made those sounds that no human throat could produce?

Llandrindod Wells appeared like a mirage. A petrol station, a retail park and a late-opening chip shop stood beneath ordinary street lights. Normal life continued as though our world had not just broken apart.

I pulled into the petrol station and asked for directions to the police station. The Dyfed-Powys Police station was a practical, modern building. We entered covered in dirt and blood, probably looking as though we had crawled from our own graves.

The desk officer took one look at us and summoned the duty inspector and paramedics.

Inspector Gareth Morgan was a weathered man in his fifties who listened with professional composure. We told him about Pen-y-Ffin, the concealed cellar and the tunnel collapse. We omitted the voices, the writing on the cave wall and the conviction that something else had been underground with Callum.

We described it simply as a tragic accident during an urban exploration trip.

"This settlement," Inspector Morgan said, studying the Ordnance Survey map. "You said it's roughly 50 kilometres south-west?"

"The track isn't marked," Mateo explained. "We followed directions from an urbex forum."

Morgan's expression tightened.

"I need the exact coordinates or a grid reference, if you have either."

I opened the location on my phone and showed him the pin I had dropped when we arrived. He studied it, then made several calls. I caught fragments of the conversations.

Recovery operation. Unstable mine passage. One casualty.

"I'm assembling a response," he said after putting down the phone. "Dyfed-Powys officers, Mid and West Wales Fire and Rescue Service, a regional cave-rescue unit, and somebody from the Health and Safety Executive Mines Inspectorate. We'll leave at first light."

"First light?"

Harriet stood so abruptly that her chair overturned.

"He's down there now. He could still be alive."

"I understand how distressed you are, but sending people into an unstable, uncharted mine passage at night could cost more lives. We will go at dawn with the appropriate personnel and equipment."

Harriet looked ready to continue arguing, but Mateo rested a gentle hand on her shoulder. She crumpled, tears pouring down her face again.

Inspector Morgan took our statements separately and asked for every detail of the collapse. When he interviewed me, I nearly told him about the sounds and what Callum had seen in the darkness. Yet, faced with Morgan's practical, no-nonsense expression, I kept silent. He would not have believed me.

He recommended a hotel on the edge of town, gave us his direct number and promised to ring with any development. We drove there without speaking and took two rooms, one for Harriet and one for Mateo and me.

I stood under the shower for twenty minutes and watched Callum's blood spiral down the drain.

When I came out, Mateo was sitting on his bed and staring at his hands.

"We left him," he said quietly.

"We had to."

"Did we?"

He looked up, and I saw my own guilt reflected in his eyes.

"Or did we panic?"

I had no answer.

We sat in silence until somebody knocked. Harriet stood in the corridor, looking small and lost.

"I can't be alone," she said.

We made room for her on one of the beds. She curled between us like a child and occasionally shook with renewed sobs.

None of us slept. We lay staring at the water-stained ceiling, waiting for dawn.

The telephone rang at 05:47. Inspector Morgan told us that the teams had assembled and were preparing to leave. We could follow if we wished, although he recommended that we remain in Llandrindod Wells.

Harriet was dressing before he finished speaking.

The convoy consisted of two Dyfed-Powys Police vehicles, appliances and support vehicles from Mid and West Wales Fire and Rescue Service, a regional cave-rescue van and an HSE vehicle. We followed in Callum's van.

The sunrise brought only a thin, cold light to the wet uplands.

Finding Pen-y-Ffin again proved more difficult than expected. Without the hill mist, the landscape seemed altered, and overnight rain had partly erased the tyre marks along the twin muddy ruts. Eventually the chapel tower appeared against the sky, leaning at an impossible angle.

The rescue teams worked with disciplined efficiency. They established a command point near the house and unloaded equipment I did not recognise.

Priya Shah, an HM Inspector of Mines, examined the cellar with a critical eye.

"This isn't standard construction," she said after her initial assessment. "That passage isn't connected to any registered mine workings in our records."

"Does that matter?" Harriet asked desperately. "Can you get through?"

Priya's expression was grim.

"We will try. But from what I can see, the collapse is extensive, and we don't know the structure of the workings beyond it."

They worked for hours. They installed supports and brought in drilling equipment, as well as a compact excavator. Mateo and I watched from a distance while Harriet paced, sometimes calling out suggestions or pleading with them to work faster.

Every report was the same. The farther they dug, the more unstable the surrounding earth became.

It was afternoon when Priya drew Inspector Morgan aside. I was close enough to hear them.

"It's too dangerous," she said. "The whole system has been compromised. If we continue, we could trigger a much larger collapse. We might lose the house and the cellar, or destabilise more of the workings beneath the settlement."

"So we leave him?" Morgan asked.

"I'm not saying that. I'm saying we need specialist national mine-rescue resources and a proper engineering assessment. This is beyond what we can safely manage with the information and equipment available."

Inspector Morgan found us sitting on the steps of the former coaching hotel, Harriet between Mateo and me. His face told us everything before he spoke.

"I'm sorry. The collapse is worse than we had hoped. We've managed to clear roughly 3 metres, but..."

He paused, choosing his words carefully.

"We've located your friend. He is visible through a gap in the debris."

Harriet made a sound as though all the air had been driven from her lungs.

"He's dead," Morgan continued gently. "He has been for some time. I'm very sorry."

"You have to bring him out," Harriet whispered.

"We're trying, but the passage is extremely unstable. The cave-rescue team leader and the mines inspector agree that continuing could cause a catastrophic collapse. We need specialist national mine-rescue resources and support from the Health and Safety Executive."

"How long will that take?" Mateo asked.

"The site isn't shown on current plans. The land ownership is complicated, and we don't yet know how extensive the unrecorded workings are." Morgan rubbed his face, looking exhausted. "I've made the necessary calls, but organising a safe recovery will take time."

"How much time?" I asked.

"Days. Possibly weeks."

Harriet rose slowly and walked towards him until only inches separated them.

"You're telling me," she said, her voice lethally quiet, "that you're going to leave him down there?"

"Harriet, don't," I said.

She began screaming.

"Don't you dare stand there and tell me Callum is going to rot in that hole because of procedures and paperwork."

Inspector Morgan met her fury with professional calm, but I saw the sympathy in his eyes.

"I understand that you're grieving, but I will not risk more lives. Your friend is gone. The best thing you can do now is allow us to proceed safely and through the proper channels."

Harriet slapped him.

The sound cracked across the abandoned high street like a gunshot. Morgan did not react. He simply stood there as she collapsed against him, sobbing.

"I'm sorry," he said quietly. "I truly am."

The teams packed their equipment as the light began to fail. Priya gave us her card and promised to press for specialist resources, but her expression suggested that she held little hope of a successful recovery.

One by one, the vehicles departed, leaving us in the empty settlement while Callum remained below.

"We can't leave him," Harriet said, staring at the house.

"We have to," Mateo replied. "For now. We can come back with more people and better equipment."

"You don't understand."

She turned towards us, and something in her eyes made my skin crawl.

"He's not merely dead down there. Something has him."

"Harriet," I began.

"You heard those sounds. You saw what was written on the wall. This place, this settlement... it's wrong. And now Callum is part of it."

I wanted to argue. I wanted to offer rational explanations. But in the dying light, with the empty windows of Pen-y-Ffin watching us, I could not.

Deep down, I knew she was right. Whatever inhabited those tunnels, whatever had made those inhuman noises, had Callum now.

We returned to Llandrindod Wells in silence, checked into the same hotel and went through the motions of ordering food that nobody ate. Harriet sat beside the window, staring into the darkness and whispering Callum's name like a prayer.

That night, I made a decision. We would return to Manchester, tell Callum's family that he was dead and leave the recovery to the authorities. We would never speak of what we had truly heard below Pen-y-Ffin.

It was the rational choice. The safe choice.

But as I finally drifted into sleep, I could still hear those wails rising from the depths. Worse, I could have sworn Callum's voice was among them, calling for help that would never come.

The drive back to Manchester took more than six hours, lengthened by the narrow mountain roads and two wrong turns. I stopped only for petrol, forcing myself onwards through exhaustion because stopping meant thinking, and thinking meant seeing Callum's face in the gap again.

Mateo sat in the passenger seat and occasionally offered to drive, but I could not release the wheel.

Harriet had not spoken since we left Llandrindod Wells. She lay curled in the back of the van with Callum's camera bag pressed against her chest as though she were holding him.

Manchester emerged through morning drizzle, waking to another ordinary day. I could not understand how everything could look so normal when our world had been fundamentally broken.

I dropped Mateo at his flat first. He paused before getting out, searching for words that did not exist.

"We should..." he began, then stopped. "I'll ring you."

Harriet lived in a converted warehouse flat in Ancoats with two other people. When I pulled up outside, she finally stirred.

"I can't," she said without moving.

"Can't what?"

"Any of it. I can't go in there and pretend. I can't ring his parents. I can't."

Her voice broke.

"We have to tell them something."

She looked at me then, properly looked at me for the first time since the collapse.

"Tell them what? That we left their son to die in an illegal tunnel beneath a settlement that doesn't exist? That we heard things down there? That he saw something before..."

"Tell them there was an accident," I said quietly. "That's all."

She laughed, bitterly and brokenly.

"An accident."

I helped her inside, carrying Callum's other equipment because she refused to surrender the camera bag. Her flatmates took one look at us, filthy, exhausted and plainly traumatised, and asked no questions.

I left Harriet in her room and drove to my own flat in south Manchester. I sat in the van for twenty minutes before finding the strength to go inside.

Calling Callum's parents was the hardest thing I had ever done. His mother answered on the second ring, her voice bright with the expectation that her son was calling.

That brightness died as I stumbled through an explanation.

A collapse. An accident underground. Recovery efforts ongoing. I was so sorry.

His father took the phone when she began sobbing. A former Royal Engineer, he asked precise questions I could not fully answer. What were the coordinates? What was the tunnel construction? What had caused the collapse? Which emergency services had attended, and why had nobody yet recovered Callum? Why had the police not contacted them directly?

I gave him Inspector Morgan's number and ended the call feeling like a coward.

The funeral took place a week later, on a grey Manchester morning that felt fitting. It was held at a crematorium and centred upon a sealed, empty coffin, though only Mateo, Harriet and I knew with certainty that there was no body inside.

Callum's parents had pressed the authorities relentlessly and even engaged a private specialist team, but every assessment reached the same conclusion. The workings were too unstable. Recovery was impossible without placing more lives at unacceptable risk.

I stood between Mateo and Harriet as the minister spoke of tragedy and God's plan. Harriet swayed on her feet, medicated but present. She had lost weight in the space of a week. Her face was thin, her eyes sunken.

Mateo stared straight ahead with his jaw clenched, holding himself together by force of will alone.

Callum's university friends filled the chapel. There was a former girlfriend from his second year, colleagues from the climbing and walking equipment shop where he worked part-time, and people who knew him as the adventurous one, always planning the next journey or discovery.

None of them knew what that spirit had finally cost him.

At the gathering after the service, Callum's cousin cornered me and asked about the accident. I muttered something about unstable ground, then excused myself and escaped to the lavatory, where I gripped the basin and fought the urge to be sick.

My reflection in the mirror looked like a stranger: hollow-eyed and haunted.

Our group disintegrated after that. Callum's gravity had held us together. Without him, we spun away in different directions.

Harriet stopped going to work at the local heritage trust. She stopped answering messages. Two weeks after the funeral, one of her flatmates rang me because she was worried.

I drove over and found Harriet's room in chaos. Books and papers were scattered everywhere. Maps of mid Wales covered the floor, with red circles marking the area where Pen-y-Ffin should have been.

"She hasn't slept in days," her flatmate whispered. "She just sits there studying those maps and writing in that journal."

I found Harriet at her desk, scribbling frantically. She looked up when I entered and, for a moment, did not appear to recognise me.

"I can hear him," she said. "At night. He's calling for help."

"Harriet, you need to sleep. You need to..."

"You don't understand."

She grabbed my wrist. Her fingers were ice-cold.

"He's not gone. He's still down there, but he's different. Changed. In my dreams he tells me things about what's beneath Pen-y-Ffin. About what took the people in 1961."

I tried to find help for her. I rang therapists and investigated grief counselling, but she refused everything, insisting that she did not need treatment. She needed to return. She needed to find Callum and understand what had happened.

A month after the accident, I went to check on her again. The flat door was unlocked. Her room was empty apart from a single sheet of paper on the desk.

Her handwriting, normally so neat, was barely legible.

I can't stay. He calls for me at night. Never contact me again.

Her flatmates had not seen her leave. She had taken nothing except her journal and research. Her mobile phone remained behind, along with everything else connecting her to her Manchester life.

I reported her missing.

But what could I tell the police? That she had gone in search of her dead boyfriend beneath a settlement which had been erased from the maps?

Mateo lasted another month before he broke. He arrived at my flat one evening carrying a bottle of whisky.

"I'm going home," he said without preamble.

"Home?"

"Barcelona. My sister's been asking me to come back for years and help with the family business."

He drank directly from the bottle.

"I can't be here any longer. Every street, every cafe... I see him. I see us planning trips and arguing about routes."

We drank in silence for a while.

Then Mateo said, "I dream about it too. The tunnel. Those sounds. Sometimes I wake and swear I can still hear them."

"Mateo..."

"Don't."

He cut me off.

"Don't rationalise it. We both know that what we heard down there wasn't natural. It wasn't human."

He left the following week. He sent one email to say that he had arrived safely, then nothing.

Like Harriet, he had severed every connection to what had happened.

That left me alone with the weight of it.

I attempted to resume an ordinary life. I went to work at the technology start-up where I debugged code, met friends for drinks and pretended everything was fine. The pretence exhausted me.

I would stare at screens filled with code and see instead the writing upon the cave wall. During meetings, my colleagues' voices would fade into that inhuman wailing.

Three months after the accident, I broke. I suffered a full panic attack in the middle of a sprint-planning meeting. My manager was understanding and suggested that I take leave. The company offered good mental-health support, he said. I should use it.

Dr Helen Barlow specialised in trauma and bereavement counselling. Her consulting room was warm, with plants and soft lighting intended to put patients at ease.

I told her that I had lost a friend in an underground accident. I omitted the erased settlement, the unnatural voices and my certainty that something else had been below us. Even sanitised, the account was enough.

"Survivor's guilt is common after events of this kind," she said. "You did what you had to do in order to survive. That is not something of which you should be ashamed."

But I was ashamed.

Every night I saw Callum's hand reaching through the gap and heard him begging us not to leave him. I saw his final expression of terror when he noticed whatever was coming through the darkness.

Between sessions, I researched. I was not obsessive, as Harriet had been, but cautious and methodical.

Information about Pen-y-Ffin was far harder to find than it should have been. Most abandoned mining settlements left extensive historical traces, yet this one appeared to have been deliberately erased.

At last I found it in the National Library of Wales digital archive.

Pen-y-Ffin had been established in 1894 and produced lead and zinc until its records stopped in October 1961. Its population at abandonment was listed as 183. The official account blamed exhausted ore veins and unsafe mine workings.

I dug further.

Issues of The Radnor Gazette from neighbouring communities told a different story. In September 1961, residents had suffered strange illnesses. There were reports of unexplained noises from the mine shafts. Children claimed that voices were calling them underground.

Then, over three days in the middle of October, seventeen people died. The paper described the deaths as mining accidents, but the details did not fit. Bodies were found inside houses and lying in the high street. Every corpse bore signs of having been underground, although many of the victims had never entered the mines.

The final local newspaper was dated 15 October 1961.

A later government-closure report dated 20 October 1961 consisted of only two short paragraphs. Investigators had declared Pen-y-Ffin unsafe for habitation. All surviving residents had been relocated. The settlement was to be left undisturbed.

Undisturbed.

We had certainly disturbed it.

In April 2019, six months after the expedition, I returned home to find a parcel outside my flat. There was no return address, but the postmark was from Penzance, Cornwall.

Inside, wrapped in brown paper, was Harriet's journal.

I nearly threw it away unopened, but curiosity prevailed. I sat at the kitchen table and read it, my hands trembling more with every page.

The early entries were what I had expected: grief, guilt and fury at Mateo and me for abandoning Callum. As they progressed, however, they became something else.

Harriet described dreams that felt more like visions. Callum appeared in her room, his body broken but still moving. He spoke in the layered, multi-toned voice we had heard beneath Pen-y-Ffin.

She had written:

He says something took him. It did not kill him. It took him.

It is old. Older than the settlement. Older than human beings.

It lives in the spaces between, in the darkness beneath the earth. The miners found it in 1961. They broke through into its domain.

It took them, changed them and sent them back to collect the others.

Callum says it still wants us. We saw too much and went too deep. It allowed us to leave that day, but only for a time.

He says it is patient. It can wait.

Sometimes I see them in crowds. People who are not quite right. They move wrongly. They smile wrongly.

Are they like Callum now? Hollowed out and filled with something else?

The final entry had been written only three days before the journal reached me.

He is not merely dead. He is something else now. I understand that. I have accepted it. Perhaps that is why he comes to me. Perhaps that is why I hear him when Tom and Mateo cannot, or will not.

I am going to find answers. Not at Pen-y-Ffin. That is only where it broke through.

I need to go deeper. I need older places, places where the barriers are thin.

Do not look for me. Do not follow.

Some doors, once opened, can never be closed.

Tell Mateo I am sorry. Tell yourself that you did the right thing.

But know this: Callum is still down there, and he is not alone. He is part of something vast and patient and hungry.

It is waiting.

I stared at the final line until the words blurred.

Then I went to the fireplace, tore the journal apart and burnt the pages one by one. I watched Harriet's words become ash and drift up the chimney. It seemed the only sane response to insanity.

Yet even as the final page blackened, I knew it would not help. Her words were already inside my head, joining the images and sounds that haunted my sleep: Callum's face in the gap, the wailing from the depths and footsteps approaching through the darkness.

I had survived Pen-y-Ffin, but I had not escaped it.

None of us had.

We had left Callum's body in that tunnel, but carried something else away with us. Knowledge that could not be unlearnt. Memories that refused to fade.

Late at night, when sleep would not come, I sometimes thought I heard his voice carried on the wind or echoing from drains. He might have been calling for help that would never come.

Or perhaps he was calling for something else entirely.

Something patient.

Something waiting.

By October 2019, I had moved roughly 320 kilometres from Manchester to London. The distance was modest on a map, but I needed an emotional gulf between myself and everything connected to Pen-y-Ffin.

Dr Barlow had called it geographical therapy: an attempt to flee trauma by changing one's surroundings. She warned me that it rarely worked, but I needed to try. I needed distance from the familiar streets where every corner held some reminder of Callum, Harriet or Mateo, and from the northern landscapes that concealed too many abandoned places.

The move did help, at least for a while.

London was all hard angles, crowds and purposeful movement. There was no room for the aimless exploration that had defined my twenties.

I rented a studio flat in Clerkenwell, close enough to walk to work, and threw myself into debugging code and building APIs for a London fintech firm. Clean logic. Predictable outcomes. Nothing like the chaos of 15 October 2018.

I even began taking photographs again, although I confined myself to urban architecture and city life. Safe subjects, present in daylight, documented, mapped and known. I no longer climbed through broken windows in pursuit of the abandoned and forgotten. My new camera remained firmly trained upon the living city.

The exhibition happened by accident.

A colleague had seen my carefully curated photographs of the London skyline, architectural details and street scenes. She mentioned that a friend was organising a group exhibition at a small gallery in Shoreditch. The theme, she said, was emerging perspectives on urban life.

I nearly refused, but there was something appealing about its sheer normality. Ordinary people doing ordinary things. No concealed doors. No passages descending beneath the ground.

The opening night was a Thursday in November 2021. The gallery was crowded with the usual art-world gathering, drinking wine from plastic cups. I stood beside my section, six large prints of London architecture photographed during the golden hour, and tried not to look as uncomfortable as I felt.

Making small talk about apertures and composition seemed surreal after all I had experienced.

"These are beautiful," a voice said beside me.

I turned and found a woman studying my favourite piece, a photograph of the Hackney Empire sign reflected in a rain puddle. She had shoulder-length blonde hair and wore a black dress with an emerald scarf that made her eyes appear impossibly blue.

"Thank you," I managed.

"The reflection creates a kind of duality," she said, tilting her head. "It's as if another city exists beneath this one."

My chest tightened.

I had thought precisely the same thing when taking the photograph, then tried very hard not to consider what might exist beneath cities, in those dark spaces human beings were never meant to enter.

"I'm Eleanor Grant," she said, extending her hand. "I work at Tate Modern, in Contemporary Collections."

"Tom Mercer."

Her handshake was firm and confident.

"I just work in technology."

"Just?"

She smiled.

"These suggest otherwise. How long have you been photographing London?"

"About two years," I said.

Two years since I had arrived. Two years since I had decided to document only what existed in the light.

We talked for twenty minutes about photography, London and other safe subjects that felt like stepping stones across dangerous water. Eleanor had an easy laugh and opinions about art that went far beyond appearances. When she said she would love to see more of my work, I surprised myself by agreeing. Our first coffee date lasted three hours.

Eleanor Grant was originally from York. She had studied art history at the Courtauld Institute of Art and spent a year in Florence examining Renaissance techniques. She approached everything with intellectual curiosity and genuine warmth. When she laughed at my terrible joke about database architecture, I felt something in my chest loosen for the first time in years.

We took it slowly. Coffee became lunch. Lunch became dinner. Dinner became long walks beside the Thames and along Regent's Canal, talking about everything except the things I could not discuss. She did not press when I said I had moved roughly 320 kilometres from Manchester to London for a fresh start. It was not the physical distance that mattered. I had wanted an emotional distance no map could measure.

She did not question me when I occasionally fell silent and stared into shadows. Four months after we met, she invited me to Tate Modern after hours for a private tour of a new acquisition. Walking through the empty galleries, listening to her voice carry across the polished floors as she explained the history of each piece, I felt safer than I had since Pen-y-Ffin. Here was someone who understood the importance of preservation and documentation, but only of things that were meant to be seen.

"You know," she said, stopping in front of a contemporary installation, "you never talk about your work from before London."

My throat tightened. "There isn't much to tell."

"You said you used to explore abandoned buildings. Urban exploration, right?"

I nodded, not trusting my voice.

"But you don't do it any more."

"No."

She studied me with the attentive eyes of an art historian, noting details without making judgements. Then she took my hand.

"All right. When you're ready, if you want to tell me, I'm here."

The relief almost knocked me over. There was no pressure, no demand for an explanation, only an acceptance that some stories took time to tell.

Eight months into our relationship, I finally told her about Callum. We were in her flat in Canonbury, rain pattering against the windows, when something in the sound brought back the water dripping in that tunnel. I went rigid on her sofa. When she asked what was wrong, the story came spilling out. Most of it, at least.

I told her about my best friend, who had died in a tunnel collapse during an urban exploration trip on 15 October 2018. I told her how we had tried to save him, but the earth had kept falling, and how I sometimes still heard his voice as I drifted towards sleep, begging us not to leave him. I told her about the guilt, the therapy and the reason I had fled Manchester.

I did not tell her about the sounds that had pursued us up the tunnel. I did not mention the writing on the cavern wall, or Harriet's journal and its warnings about patient, hungry things. Some truths were too heavy to share and too dangerous to speak aloud.

Eleanor held me as I talked, occasionally wiping away tears I had not realised were falling. When I finished, she remained quiet for a long moment.

"You did what you had to do to survive," she said at last. "That isn't abandonment. It's being human."

"His parents had to hold a funeral at a Manchester crematorium with an empty coffin."

"And if you'd stayed, they might have had to bury you as well. Would that have been better?"

It was the same logic I had heard from Dr Helen Barlow and Mateo, and from the rational part of my own mind. Somehow, in that rain-softened moment, hearing it from Eleanor made me almost believe it.

Our relationship deepened after that night. She understood why I sometimes froze beside construction sites where deep foundations were being excavated, why I avoided the Tube whenever possible and preferred buses or walking, and why I needed lights left on in the flat even when I slept. She never made me feel broken. She adapted. She put nightlights in the hallway, suggested restaurants with outdoor tables and planned trips to museums, galleries and theatres - all above ground, all in the light.

Two years became three, and as our fourth anniversary approached, her flat became home in my mind. We developed routines. Saturday mornings at Islington Farmers' Market. Sunday afternoons at Tate Modern. Wednesday dinners at the Thai restaurant where the staff knew our order by heart. It was a normal life, the sort I had thought I would never have again.

In October 2025, over champagne at a restaurant overlooking the Thames, Eleanor drew a key from her handbag.

"I've been thinking," she said. I could tell she was nervous from the way she turned her wine glass by the stem. "My tenancy ends next month. There's a beautiful flat to rent in a converted Victorian townhouse in Canonbury. Two bedrooms, so you could have a proper office. Original wooden floors and masses of light."

"Are you asking me to move in with you?"

"I'm asking whether you want to build something together. A real home."

I thought of my small Clerkenwell studio flat, which still felt temporary after six years. I thought of waking beside her every morning rather than only at weekends. I thought of having someone there when the nightmares came.

"Yes," I said. "God, yes."

She laughed - that bright sound which had first drawn me to her - and kissed me there in the restaurant.

The flat was perfect. It occupied the second floor of the converted townhouse, with huge windows flooding every room with light. Original Victorian details sat comfortably beside modern fittings. The second bedroom would indeed make an ideal office, with built-in bookshelves and east-facing windows for the morning sun.

We moved in on a crisp Saturday in October. Friends helped us carry boxes up the stairs. I had accumulated more than I realised during my years in London: photography equipment, books and clothes that were not merely jeans and flannel shirts. Evidence of a life rebuilt.

While unpacking my office that evening, I found something at the bottom of a box I did not remember packing. My old exploration journal.

Its leather cover had been worn soft by years of handling. I sat on the floor holding it as if it might bite me. I had not opened it since before Pen-y-Ffin. I had never been able to throw it away, but neither could I bear to look inside.

It had travelled with me from Manchester to London, hidden inside boxes within boxes like a secret tumour.

"What's that?" Eleanor asked from the doorway. She was carrying two mugs of tea.

"An old journal," I said. "From before."

She put down the tea and sat beside me. She did not touch the journal, but she did not draw away from it either.

"Your exploration notes?"

I nodded. Inside were maps, location details and photographs fixed to the pages. They recorded all our adventures before the final one: Callum's handwriting in the margins suggesting routes, Harriet's sketches of architectural details, Mateo's historical notes in his precise script.

"I should throw it away," I said.

"Should you?"

I looked at her. "It's the past. We're building a future."

"The past is part of you. It shaped who you are." She touched my hand gently. "But if you need to let it go, I understand."

I stood with the journal and carried it to the kitchen bin. For a full minute I remained there. Then I lifted the lid and dropped it in.

It landed with a soft thud on top of coffee grounds and takeaway containers.

"All right?" Eleanor asked.

"Yes. I think so."

We returned to unpacking, arranging our new life in rooms filled with light. By evening, the flat was beginning to feel like home. We ordered a takeaway curry and ate it on the sitting-room floor among the boxes, tired but happy.

That night, in our new bedroom, with boxes still stacked against one wall, I dreamed of Callum for the first time in more than a year.

He stood at the foot of the bed, still wearing the clothes in which he had died. Something was wrong with him. His body was twisted, the bones set at angles that made no sense. His skin was grey, like old meat, and his eyes were flat and black and empty.

His mouth formed words I could not hear. He gestured frantically, pointing at something behind me. I tried to turn, but I could not move.

Trapped in the paralysis of the nightmare, I watched Callum's silent screaming become more desperate and his movements more frantic. Then I noticed what lay beneath his skin.

Things were moving there. They writhed and pressed against the surface as if he were filled with snakes.

His mouth opened wider, impossibly wide, and I could see down his throat into a darkness that continued for ever.

I woke gasping, the sheets soaked with sweat. Eleanor stirred beside me but did not wake. My heart hammered as I stared at the foot of the bed where Callum had stood.

It was empty, of course. There were only boxes waiting to be unpacked and shadows cast by the street lamp outside. The strain of moving, I told myself.

The journal had stirred old memories. That was all. I had thrown it away and symbolically released the past. The dream was simply my subconscious processing the act.

I got up for water and padded barefoot into our new kitchen. The wooden floor felt cold and unfamiliar beneath my feet. I filled a glass at the tap and stood by the sink, looking down at the quiet street.

A normal neighbourhood on a normal night. A cat crossed the road. A television flickered in a window opposite.

When I turned, I saw the water on the floor.

A trail of wet footprints led from our front door through the sitting room. I followed them with my eyes, the glass trembling in my hand. They continued along the hallway, paused outside the office and then went on towards our bedroom.

My first thought was that I had made them myself, perhaps after stepping in something wet outside. But I had been in bed for hours. The prints were too large to be mine as well.

They were wrong. The toes were too long and splayed at unnatural angles.

I followed them to the bedroom doorway. Eleanor was still asleep, breathing steadily. The footprints led to the foot of the bed, exactly where Callum had stood in my dream, and then vanished.

No. They had not vanished.

They went beneath the bed.

I stood frozen, the water forgotten in my hand. Every rational part of my mind insisted it was impossible. Wet footprints did not simply appear. Things did not hide beneath beds except in children's nightmares. But Pen-y-Ffin had taught me that rational explanations were not always the correct ones.

Slowly, I knelt beside the bed. My hand shook as I reached for the edge of the valance. I had to look. I had to know.

"Tom?"

Eleanor's sleepy voice made me jerk backwards.

"What are you doing?"

I stood too quickly and nearly spilt the water. "I thought I heard something. I was just checking."

She squinted at me in the dimness. "Come back to bed. It's probably the radiator. Old buildings make strange noises."

"Yes. You're right."

I climbed back into bed and pulled her close. She fell asleep again almost at once, but I lay awake staring at the ceiling. The glass of water sat forgotten on my bedside table. I tried not to think about the wet footprints I could no longer see in the darkness, or about what might be waiting beneath our bed.

I would look in the morning, I told myself, when sunlight filled the room, Eleanor was awake and the world made sense again. I would find nothing. Perhaps there was a leaking pipe or condensation from the radiator. There would be a perfectly reasonable explanation.

Deep within me, in the part that remembered inhuman wailing in the tunnels, I knew better.

Some doors, once opened, could never truly be closed. Some things, once seen, followed you no matter how far you ran. I had thrown away the journal, but I could not discard what had happened at Pen-y-Ffin. I could not forget that we had left Callum in that tunnel with something that should not exist.

Seven years later, in a beautiful London flat filled with light, love and new beginnings, the wet footprints beneath our bed suggested that Callum - or whatever Callum had become - had not remained buried after all.

One week after the dream, I stood in the bathroom doorway and watched Eleanor at the basin as she went through her nightly routine. She caught my eye in the mirror and smiled. Half her face was covered in an expensive cream that smelt of lavender.

"You're staring," she said, reaching for a flannel.

"Just admiring the view."

She laughed and flicked water at me. "Charmer. Will you check that I locked the front door? I can't remember whether I did when we came back from dinner."

I padded along the hallway, passing the office where I had been editing photographs earlier. The floorboards creaked at that particular spot near the kitchen. We had been meaning to have it repaired.

Beyond the sitting-room windows, Canonbury lay quiet beneath the street lamps. A few people were walking dogs before bed.

The deadlock was already secured. Of course Eleanor had locked it. She always did. I was the one who sometimes forgot, a habit left over from an easier life in Manchester, before I learnt what doors were meant to keep out.

I was turning away when the doorbell rang.

It was 23:38. The green digits on the microwave caught my eye as I passed the kitchen. Who the hell would ring our bell so late?

"Probably Neil," Eleanor called from the bathroom.

Our downstairs neighbour had locked himself out twice in the past month, both times after what he called networking events at the pub along the road.

"Tell him he really ought to hide a spare key somewhere."

I switched on the landing light and looked through the spyhole. The fisheye lens distorted everything, but I could see no one outside. Perhaps it was children playing a prank, though it was very late for that.

I released the deadlock and opened the door.

The landing was empty. Cold October air moved in, carrying the smell of dead leaves and something else - wet copper and freshly disturbed earth.

My hand tightened around the door handle.

"Hello?"

Something moved at the edge of the landing light.

A figure stepped out of the shadows beside the stairs. It moved wrongly, its gait halting and uneven, like someone walking on broken bones. Then it came fully into the light and my legs nearly gave way.

Callum.

But not Callum. Not any more.

His body was twisted at angles my eyes struggled to comprehend. One shoulder stood higher than the other. His entire torso canted sideways, as if his spine had been dismantled and put back incorrectly. His flannel shirt and jeans - the clothes he had worn that day - hung in tatters, caked with earth and darker stains. His exposed skin had turned grey, the colour of meat left too long at the back of a refrigerator.

His face was the worst. It still bore Callum's features, but they were slack and empty. His eyes were entirely black. There were no whites, no trace of life, only two holes that seemed to swallow the light.

"You left me," he said.

The sound came from his throat, but it was not his voice. Several voices spoke at once, Callum's layered with others and harmonising in ways no human vocal cords could produce. The sound made my teeth ache.

I slammed the door and threw the deadlock. Then I stumbled backwards until I struck the wall.

This was not happening. It could not be happening.

Callum was dead, crushed beneath tonnes of rock in the Cambrian Mountains. I had attended his funeral at a Manchester crematorium and watched his family mourn over an empty coffin.

The door swung open.

It was not kicked or forced. It simply opened as if the deadlock were not there, as if solid wood were merely a suggestion.

Callum stepped into our flat. Every footfall left behind earth mixed with a black, viscous substance that moved by itself, creeping away from his prints like living oil.

The smell intensified: decay, copper and something chemical that burnt my nostrils.

"Tom?" Eleanor called from the bathroom. "Who was it?"

I could not answer. I could not move.

Callum tilted his head to an angle that would have broken a living person's neck and studied me with those empty black eyes.

"You left me in the dark," he said in that dreadful choral voice. "But the dark was already full."

Things moved beneath his skin. They pressed against the surface like fingers seeking a way out. His face rippled and its features shifted as whatever lived inside rearranged itself. A bulge travelled up his neck, distorting his throat before disappearing behind his jaw.

"What are you?" I whispered.

"I'm your friend. Your friend whom you left to die. But I didn't die, Tom. I became."

Eleanor came into the hallway, still patting her face dry with a towel.

"Seriously, who..."

The towel fell from her hands. The scream torn from her was pure, instinctive terror. She pressed herself against the wall, eyes wide, unable to look away from the thing wearing Callum's body.

"Hello," Callum said, turning his terrible attention towards her. "You must be the new girlfriend. The one who helped him forget."

"Eleanor, run!" I managed to shout. "Get out now!"

She could not move. She stood frozen like an animal caught in headlights.

Callum took one step towards me, then another. Each movement was jerky and unnatural, like a puppet operated by someone who did not understand the human body. More black fluid dripped from him and pooled on our wooden floor.

"The tunnel went deeper than you knew," he said. "It connected to places older than Pen-y-Ffin, older than human beings. The miners broke into its domain in 1961. It had waited so long. It was so hungry. It took them first, made them its vessels and sent them up to collect the others."

He came closer. I could see that parts of him remained crushed, still bearing the damage of the collapse. Ribs projected through tears in his shirt at impossible angles. One arm bent in too many places. Whatever animated him had no concern for the body's limitations.

"It's patient," Callum continued. "It can wait decades between feedings. But you three - you four - came straight to it. You delivered yourselves like an offering. It needed only one at first. To test. To taste. To learn."

"You're not Callum."

I pressed myself harder against the wall, wishing I could pass through it.

"Callum is dead."

"Yes."

That terrible smile appeared.

"Callum died screaming in the dark. He felt it crawl inside him, reshape him and make him useful. But his memories are still here. His love for you. His trust. The trust you betrayed when you let go of his hand."

The lights flickered. The hallway fitting dimmed, brightened and dimmed again. In those pulses of light, Callum's body seemed to alter, offering glimpses of something else beneath it - something vast, dark and patient.

"Now it wants the rest of you," he said. "The ones who saw too much. The ones who know about the door we opened."

He smiled more widely.

"Harriet understood first. She went searching for me, following the dreams I sent her into older, thinner places. Mateo took longer, but Barcelona was not far enough to run."

"No."

The word emerged cracked and feeble. "They escaped. Harriet disappeared. Mateo went home."

"Mateo came home," said a new voice behind Callum.

The front door still stood open. Two more figures waited on the landing, silhouetted against the light. They moved forwards with the same broken gait, and at last my legs failed me.

I slid down the wall as Mateo and Harriet entered our flat.

Mateo's scholarly appearance was gone, replaced by something that had crawled out of a nightmare. His skin had the same dead grey colour. His clothes, different from those he had worn at Pen-y-Ffin, were stained with soil and darker substances. One lens of his spectacles was cracked, and the eye behind it was entirely black. His head hung at an unnatural angle. His neck was plainly broken, yet it still bore the weight.

Harriet was worse.

Her body moved with a dancer's grace, but wrongly. Each gesture was too smooth, too precise, too inhuman. Her hair hung in matted clumps. When she smiled, I saw that her teeth had been replaced by something resembling black glass.

"Hello, Tom," Mateo said. His voice possessed the same many-toned resonance. "Barcelona was lovely, but the thing below found me all the same. It's everywhere, you see. Waiting beneath every city and every town. All the deep places connect if you go down far enough."

Harriet tilted her head and studied Eleanor through her empty eyes.

"She's pretty," she said. "Alive. Full of light. It will enjoy draining that from her."

The lights went out completely.

In the absolute darkness, Eleanor cried out. It was a short, sharp sound, cut off far too quickly. Then there was silence, except for breathing from too many throats, in rhythms that did not belong to human lungs.

"Eleanor!"

I pushed away from the wall and stumbled forwards, my hands extended into the darkness. My fingers met nothing but empty air.

A hand closed around my wrist. It was cold - far too cold - and had too many joints.

"Time to go, Tom," Callum's chorus whispered directly into my ear. "Time to go down. Time to join us in the dark where you left me. Where you left all of us."

More hands seized me and pulled. I fought them, straining against grips like iron wrapped in rotting flesh. In the darkness I heard them moving around me. I smelt earth, decay and that chemical taint which made my head swim.

"Eleanor!"

I screamed her name, but only silence answered.

Then Callum spoke again, so close that I felt the wrongness of his breath against my face.

"She'll join us soon. Everyone does, eventually. But first you need to understand. You need to see what you condemned me to. What waits beneath every place human beings believe is safe."

The hands pulled harder, dragging me towards the door, or perhaps towards somewhere else. In the complete darkness, direction ceased to mean anything. Harriet hummed a tuneless melody that seemed to emerge from several throats within her body. Mateo whispered in languages older than human speech.

My feet could find no purchase on the floor. The hands lifted and carried me.

Then, with mounting horror, I understood that we were going down.

Not down the stairs. Not down to the street. Down in a way that should have been impossible from a second-floor flat.

Down into the interconnected darkness beneath London.

Down to where patient things waited.

Down to where Callum had waited seven years to show me what I had left him to become.