The Voices Beneath Blackthorn Hospital

I never thought I'd end up best friends with someone like Callum Vane. It began during our final year at Millcombe Academy sixth form, when I was still convinced he was just another loud bloke desperate for attention. Callum had a way of taking up all the space in any room he entered, cracking jokes that were not always funny and telling stories in which he somehow always emerged as the hero. Most people either loved his energy or could not bear being around him for more than five minutes.

I fell firmly into the second camp.

My opinion changed on an ordinary Thursday afternoon in October. I was sitting alone in the library, working on a photography project about local architecture, when Callum dropped into the chair opposite me. He had been watching me leaf through photographs of old buildings in Millcombe town centre for about ten minutes before he finally spoke.

"You know there's an abandoned engineering works about twenty minutes outside town, don't you?" he said, keeping his voice low enough that Mrs Cartwright would not throw him out. "Built in the 1930s. Made railway components. Most of the original machinery is still inside."

I looked up from my photographs, ready to brush him off with some polite excuse about being busy, but there was something different about his face. His usual manic grin had vanished, and he seemed genuinely interested. He was actually studying my work instead of merely waiting for his chance to speak.

"How do you know what's inside?" I asked.

"Because I've been there."

He leant forwards and lowered his voice further.

"Last weekend. Found a way in through a loading bay door that doesn't lock properly any more. The place is incredible, Jamie. Like stepping back in time."

I studied his face, trying to decide whether this was an elaborate joke. Callum Vane did not seem like someone who would care about old buildings or industrial architecture, but he carried on describing the works in extraordinary detail. He told me where the machinery stood, how the overhead cranes crossed the roof space and how sunlight shone through the broken upper windows onto rows of belt-driven lathes.

"Want to see it?" he asked. "This Saturday. I could show you round."

Looking back, I should have said no. I should have stuck to photographing buildings from outside, where breaking and entering was not involved. But something about the way he described the place made me curious. The thought of seeing industrial history preserved exactly as the workers had left it decades earlier fascinated me, particularly because I already spent hours reading about local historical sites.

"What if we get caught?" I asked.

"We won't." His confidence was infectious. "The place has been empty for fifteen years. Nobody checks it any more."

That Saturday, I met Callum at the abandoned Millcombe engineering works, a vast brick complex surrounded by chain-link fencing and waist-high weeds. He had been right about the loading bay. The metal door had warped so badly over the years that it no longer sat flush in its frame. We squeezed through the gap, and I found myself standing in a cavernous workshop filled with rusting machinery, overhead cranes and shadowy ranks of lathes.

The place was everything Callum had promised and more. Decades of dust covered the workbenches, where someone had left tea mugs and hand tools as though the workers had simply gone out for lunch and never returned. We spent most of the afternoon photographing everything, from the immense overhead cranes to the belt-driven lathes and the clocking-in machine still fixed beside the entrance, with employees' cards scattered across the floor beneath it.

Callum turned out to be the perfect exploration partner. He knew how to move quietly through unstable areas and had a knack for finding the most interesting rooms. More importantly, he understood why such places mattered. While I concentrated on photographing small, telling details, he researched the people behind them. He had found old newspaper reports about the works' closure and knew which Millcombe families had worked there for generations.

"These buildings are time capsules," he said as we climbed a metal staircase carefully towards the first floor. "Everyone drives past them on the main road, but they're full of stories nobody can be bothered to learn."

That afternoon changed everything between us. The irritating attention-seeker from sixth form turned out to be someone who genuinely cared about recovering forgotten pieces of history. His energy, which had seemed so obnoxious in the corridors at school, became infectious enthusiasm whenever he focused it on exploring and documenting a place.

Over the following months, we became unofficial partners. Callum would research possible sites online or hear about them through the loose network of urban explorers he had somehow joined. I brought the photography skills and historical research that made our trips feel like something more worthwhile than trespassing for the thrill of it.

We visited a derelict lace works in a neighbouring district in Nottinghamshire, where unfinished pattern cards remained on the benches, thread was still mounted on the frames and staff ledgers from the late 1970s lay scattered around the front office. A closed village primary school outside Millcombe became our largest project, with three floors of classrooms frozen in time. Chalkboards still bore fragments of lessons, faded work covered the display boards, and exercise books remained inside wooden desks.

Each place taught us something new about the region's industrial past and the communities that had built their lives around buildings that now stood empty. More than that, they taught us how to work together.

Callum's willingness to take risks balanced my tendency to overthink every decision. My careful documentation complemented his instinct for finding the most interesting spaces inside larger structures. By the time we left sixth form, we had explored more than a dozen sites across Derbyshire, Nottinghamshire and South Yorkshire. What had begun as curiosity had become a proper hobby, something we both anticipated eagerly despite the risks.

Even when we went to different universities, we made time for weekend trips whenever we were both home during the holidays.

The call came on Tuesday, 12 December 2023, while I was editing photographs from our latest expedition to some disused riverside maltings and grain silos that had stood empty since the late 1990s. Callum's name appeared on my mobile just after 20:00.

"I found it," he said without bothering to say hello. "The one we've been waiting for."

"Found what?"

"Blackthorn Hospital. The secure psychiatric wing on the hill. I've been trying to get into that place for two years."

I knew the building he meant. Everyone in Millcombe did. Blackthorn Hospital was a four-storey Victorian mass of dark brick standing on Blackthorn Hill above the town centre and the Derwent valley. You could see it from almost anywhere in Millcombe. The original infirmary had opened in 1911, and its secure psychiatric wing had been added in 1936. It had stood empty for decades, but unlike our usual targets, it came with stories that went far beyond those of an ordinary abandoned building.

"Callum, that place is supposed to be haunted."

I kept my voice neutral, reluctant to encourage what would probably become an argument about supernatural nonsense.

"Come off it, Jamie. You know that's local folklore meant to keep people away from a structurally unsound building." His laugh crackled through the phone. "Although I'll admit the stories are imaginative. Patients who never died. Voices calling from empty rooms. Mysterious disappearances. Classic small-town ghost tales."

He was right, of course. Every abandoned building acquired its share of ghost stories, particularly places with histories as bleak as Blackthorn's.

Still, I had to admit that the hospital interested me. It was enormous, with intricate architectural details visible even from a distance, and I often wondered what remained inside after so many years.

"How would we even get in?" I asked. "That place has been locked up tight since the regional health authority closed it after the inquiry."

"Leave that to me. I've been studying the layout for months. Found some old plans online, along with maintenance records from its final years. There are definitely ways in if you know where to look."

Excitement was building in his voice, the same tone he adopted whenever he found a promising new site. Yet something about this felt different. It was bigger and more complicated than our usual weekend trips.

"When were you thinking?" I asked.

"Friday night. That gives us time to do proper research and gather all our equipment. I'm talking about a serious expedition, not a quick look round."

The timing suited me. I had no other plans for the weekend, and I had to admit that photographing the interior of Millcombe's most infamous abandoned building would make a significant addition to my portfolio.

But Callum had not finished selling the idea.

"You're not getting cold feet, are you?" he asked. "Because I remember when you used to be excited about pushing boundaries and discovering places nobody else had documented. You've been playing it rather safe lately."

That stung more than I wanted to admit. He was not entirely wrong. Our recent explorations had been fairly tame: buildings that were easy to enter and unlikely to bring serious legal consequences if we were caught. I had been choosing places that were interesting but safe, while Callum continued to press for more challenging sites.

"I'm not getting cold feet," I said. "I just think we should be sensible about how we approach something this big."

"Fair enough. But this is our chance to document something genuinely important. Think about it. Blackthorn has been sealed for years. Whatever's inside is probably exactly as they left it when the official inquiry forced the place to close."

He had a point. The hospital offered a unique opportunity for our historical project. It was an immense building that had stood empty for decades, and its grim reputation had deterred most vandals and explorers from going inside.

"All right," I said. "Friday night. But we do it properly. Full research, the right equipment, and care at every step."

"Absolutely. I'll start gathering what we need. Cameras, spare batteries, high-powered torches. Might bring bolt cutters as well, in case we find any locked doors worth opening."

After we ended the call, I sat in my flat looking at the photographs from the maltings. Each image preserved details that would otherwise be lost because nobody had taken the time to record them. That was what gave our hobby meaning for me. We were saving stories that might otherwise disappear for ever.

Blackthorn was the greatest challenge we had attempted, but it also promised the greatest reward. If we could enter safely and photograph its interior, we would create a record of a building most people would never see.

I spent the rest of the week researching everything I could find about Blackthorn Hospital: its history, its layout and the reason it had been abandoned. The original infirmary had opened in 1911. The psychiatric wing followed in 1936. In December 1987, an official inquiry had led the regional health authority to close the entire institution and withdraw its authority to operate. By Friday afternoon, I had filled three notebooks and prepared a complete equipment list.

Callum had been right about one thing. This would be our biggest exploration yet.

At exactly 20:30 on Friday, 15 December 2023, I drove my ageing Vauxhall Astra onto the forecourt of a petrol station on the edge of Millcombe. Callum's battered Ford Fiesta was parked near the boundary beneath a flickering lamp. He was leaning against the driver's door with a manila folder tucked under one arm and his familiar grin spreading across his face as I approached.

"Right on time," he said, straightening as I took my camera bag from the passenger seat. "You ready for this?"

The weight of the equipment across my shoulder was reassuring: camera body, spare lenses, backup batteries and the small tripod I had packed in case we found something worth documenting properly. Callum looked as if he had dressed for a military exercise. His combat trousers bulged with what I assumed were lock picks and various exploration tools, while his waxed jacket probably concealed more equipment than I wanted to know about.

"Show me what you found," I said, nodding towards the folder.

He opened it and spread several sheets of paper across the bonnet of his Fiesta. The floor plans looked authentic enough, although repeated photocopying had blurred some of the detail. I examined the layout by torchlight, making out the main corridors, offices and what appeared to be patient wards radiating from a central hub.

"These came from Derbyshire Record Office," Callum explained, indicating various sections with one finger. "But look here. The basement is marked as storage and utilities, with no detailed layout at all. Just blank space where the room specifications ought to be."

He was right. The footprint of the building suggested a substantial basement, but the plans showed almost nothing beneath ground level. I had seen similar gaps in records before. Architectural files were often incomplete, particularly for large buildings with complicated mechanical systems.

"Perhaps they never deposited the detailed basement plans," I said. "Or the records were lost over the years."

"Maybe. But I've studied satellite images, and the foundations suggest there's far more space underground than these show."

Callum folded the papers and returned them to the folder.

"I suppose we'll find out once we're inside."

Blackthorn Hospital towered against the night as we followed the winding road up the hill in my Astra, my headlights occasionally catching sections of its vast brick frontage through the trees. Even from a distance, I could see broken windows and places where portions of the roof had collapsed. It looked precisely like what it was: a place abandoned and forgotten for decades.

We parked roughly 180 metres away, behind a stand of Scots pine that concealed both my Astra and Callum's Fiesta from the road. The December air was bitter when I stepped out, and our breath formed white clouds that vanished quickly in the wind.

"Temperature's dropping fast," I said, adjusting my jacket and shifting the camera bag higher on my shoulder.

"Good. Fewer people out tonight to notice us nosing about."

Callum switched on his torch and tested the beam. Then he drew out another and handed it to me.

"These are the high-powered ones. They should give us plenty of range inside."

A strong mobile signal showed on my phone before I put it away.

We approached on foot, our boots crunching over patches of snow that had survived in the shadows beyond the reach of the afternoon sun. Blackthorn looked still more imposing at close quarters, its dark walls rising four storeys above us and its wings stretching away on either side of the main entrance. Most ground-floor windows had been boarded decades earlier, though time and weather had loosened many of the boards.

The silence felt absolute in a way that seemed unnatural. Millcombe lay across the valley below, street lamps tracing the residential roads, yet no sound carried up the hill. There was no traffic, no distant voices, not even the electrical hum one would expect near a building of that size.

"Dead zone," Callum said, following my gaze towards the town. "Sound doesn't travel well up here. Something about the position of the hill."

We circled the hospital, testing loose boards and looking for a way in that would not require us to break anything. Most of the ground-floor windows were secure, but on the south side we found what we needed. A window opening about 1.2 metres above the ground had lost all its glass, leaving a space large enough to climb through. The wooden frame was rotten, and beyond it I could see what appeared to be an office, with a desk pushed against one wall.

"Administrative wing," Callum said after checking his floor plans. "It should connect to the main corridor system from here."

I hauled myself through first and dropped carefully onto the debris-covered floor. The smell struck me at once: mould, damp plaster and something else I could not identify. Perhaps it was decay, or simply the accumulated stench of a building that had remained sealed and neglected for decades.

Callum climbed in after me, and we switched on our torches for our first proper look at the interior.

The room had plainly once been an office. A metal desk leant at an angle against one wall, and filing cabinets lay toppled around the room. Dark water stains spread across the ceiling. Strips of wallpaper hung down, exposing damaged plaster beneath. Papers covered the floor, mixed with fallen plaster and pieces of insulation from the ceiling.

I picked up one sheet. Water had damaged it too badly to read, although I could just make out the structure of what might have been a patient admission form.

"This is incredible," Callum said.

He took out his camera and began documenting the scene. His flash lit the office in harsh bursts, revealing details our torches had missed: layers of graffiti covering one wall, some of it clearly recent, and furniture piled in corners as though someone had once tried to barricade the windows from within.

I took out my own camera and worked methodically through the room. I photographed the desk with its drawers hanging open and papers spilling out, the overturned filing cabinets, and the peeling paint that had probably once been green but now resembled old moss. Each image captured a fragment of the building's story: the speed of its abandonment, the slow progress of its decay and occasional signs that other explorers had entered before us.

Yet the office felt different from the industrial sites we usually photographed. It was more personal, somehow, as if the people who had worked there had left something of themselves behind.

"Look at this," Callum called from what had once been the reception area.

He was photographing a ward diary lying open on a small table. Its pages were yellow but still legible.

"It ends on 22 December 1987."

I joined him. The diary contained a full schedule of meetings, appointments and ward business, with handwritten notes in the margins showing an ordinary working day continuing right up to the final entry. After 22 December there was nothing, only blank pages through the rest of the month and into the new year.

"They closed quickly," I said, taking photographs from several angles. "It looks as though they were operating normally and then simply stopped."

Once we began looking for it, evidence of sudden abandonment was everywhere. Tea mugs remained on desks, their contents long since evaporated or soaked into the papers beneath them. A coat hung from a hook beside the door. Family photographs, small decorations and a half-finished cryptic crossword lay around the office as if the staff had walked away from their work expecting to return the next morning.

Callum moved to the doorway leading further into the building. His torch beam cut through the darkness of what appeared to be a main corridor.

I finished documenting the office and joined him, looking into a passage that extended beyond the reach of our lights.

"Main administrative corridor," he said, checking his plans. "It should lead to the patient wards and the central hub. Ready to see what else they left behind?"

I adjusted my camera for the poorer light and checked that my spare batteries were within easy reach. Whatever waited in the deeper parts of Blackthorn, I wanted to document it properly. The corridor ahead was so dark that even our torches seemed inadequate, and I found myself wondering what remained in the rooms beyond.

Callum and I stepped into the main corridor together, our torch beams moving across the walls.

The passage ran in both directions, with open doorways spaced along it. Water damage had left long stains down the walls, and fragments of plaster shifted beneath our boots. The cold struck me immediately. It was not merely the December chill from outside, but something deeper that seemed to emanate from the building itself.

I pulled my jacket tighter and watched my breath cloud in the torchlight.

"It's getting colder," I said, checking the digital display on my watch. "The further in we go, the worse it feels."

Callum was already heading towards the nearest doorway with his camera raised.

"It's probably just the lack of heating. These old places don't hold warmth once the system is shut down."

He entered what appeared to be a patient room, and I followed.

Two rusted bed frames stood against opposite walls, stripped of their mattresses. A small window near the ceiling was boarded, but narrow gaps admitted thin strips of light from outside. Medical equipment I could not identify sat in the corners beneath dust thick enough to write in.

I began taking photographs, capturing the bed frames from different angles and concentrating on details that conveyed how long the room had stood empty. A call button hung from a cord beside one bed, its plastic yellowed with age. Someone had scratched initials into the wall near the headboard, and I wondered whether they belonged to a patient or a member of staff.

"Have a look at this," Callum called from across the corridor.

I found him in another patient room, this one containing three beds arranged in a semi-circle. Unlike the previous room, it still held personal belongings. A pair of slippers stood beside one bed, and magazines from the 1980s lay open near the window. A chipped ceramic robin rested on a bedside cabinet.

"They left in a hurry," Callum said, photographing the magazines with his flash. "Look at the dates. December 1987, just before the closure."

We spent the next hour moving from room to room, taking notes and photographs of what seemed to be an entire record of hospital life stopped in an instant. Each room revealed something new about the people who had lived and worked there. The patient rooms held abandoned clothes, books and letters. Staff areas contained clipboards with duty rotas still attached and tea mugs standing on desks as though their owners had only stepped away.

The nurses' station was particularly striking. Charts and paperwork covered the main desk, some held in place by a brass ward bell and a glass ink bottle. Patient files lay scattered across the floor, though damp had rendered most of the writing illegible. A large scheduling board occupied one wall, with patients' names written in different colours to indicate treatment programmes or dietary requirements.

I photographed it all systematically, trying to capture the human lives within the abandoned place. Behind the station, medication charts hung from metal hooks, listing dosages for patients whose names I could not always decipher and whose conditions sounded severe even to someone without medical training.

Callum concentrated on the administrative records, finding logbooks that tracked daily operations until the final entries.

"They were still processing admissions on 22 December," he said, pointing to a line in a bound ledger. "Then nothing. As if somebody switched off the lights and walked away."

The building's acoustics troubled me more as we moved deeper into the ground floor. Our voices sounded muffled, as though the walls absorbed sound. Even with rubble covering most surfaces, our footsteps were much quieter than they should have been. I began speaking more loudly than necessary simply to hear my own voice.

"It sounds wrong in here," I said, clapping my hands to test the space.

The sound vanished almost at once instead of echoing as it would have done in any of the other large buildings we had explored.

"Probably the water damage," Callum replied, although I noticed that he too had begun raising his voice without seeming aware of it. "Moisture changes how sound travels through a space."

We continued documenting patient rooms, supply cupboards and small offices that had served various medical purposes. Each told part of the same story: normal work interrupted without time for proper closure procedures. Equipment remained precisely where someone had last used it, and personal possessions lay abandoned as though their owners had expected to return the following day.

The pattern continued until we reached a corridor near the east wing.

This passage looked different from the others. Its walls were painted institutional white rather than the faded green found throughout the rest of Blackthorn, and the floor showed considerably less water damage. More strikingly, every door bore a sign restricting access to authorised personnel.

I counted eight doors, evenly spaced along both sides of the corridor. Seven stood open, revealing empty rooms with concrete floors and heavy-duty electrical sockets built into the walls. The eighth, at the far end, remained closed. A deadbolt far newer than any other fitting we had seen secured it.

"This section feels different," I said, aiming my torch down the corridor. "Look at the condition of the walls compared with everything else."

Callum was already examining the warning signs beside the doors.

"Authorised personnel only. Restricted access. Medical staff clearance required."

He photographed each sign carefully.

"These rooms were definitely kept off limits to ordinary patients."

I approached the closed door and felt a chill when I saw the paper fixed to it.

The sheet was white, the message handwritten in red ink that looked far too fresh for a building abandoned for thirty-six years.

"DO NOT OPEN. IT KNOWS YOUR VOICE."

The words had been printed in block capitals with what appeared to be a red marker pen. Unlike everything else in Blackthorn, the warning showed no age, water damage or fading. The paper looked new, as though someone had put it there recently.

"Callum, look at this."

He joined me and trained his torch on the handwritten message. For a moment his habitual confidence faltered as he studied the paper's perfect condition. Then he laughed, although the sound was forced.

"Classic scare tactic. Some local kids probably put it up to keep other explorers away from whatever they found in there."

I stared at the warning, trying to reconcile its condition with the decay surrounding us. Everything else bore the marks of decades of neglect: water damage, mould, faded paint and rotting paper. This could have been written the previous day.

"The ink's too fresh," I said. "Look at the paper. It doesn't match anything else here. Somebody might have put it up last week."

"That doesn't make it supernatural."

Callum was already taking his lock-pick set from his combat trousers.

"It's probably another explorer trying to claim the room as a private discovery."

I stepped back while he examined the deadbolt. The lock was plainly newer than the original door furniture, though the weathering suggested it had been installed months or perhaps years earlier rather than recently.

"We should respect the warning," I said. "Whoever left it may have had a reason."

"Come on, Jamie. You know better than that."

Callum selected two picks and began working on the mechanism.

"These places collect ghost stories. Every abandoned hospital in the country has somebody claiming it's haunted. It's folklore designed to keep people away from dangerous buildings."

He had a point. Every site we had visited came with supernatural rumours, generally founded on nothing more than a bleak history and the way empty spaces distorted people's senses. Yet this warning felt different. It was too immediate to belong to the usual local folklore.

I checked my watch and realised we had been inside Blackthorn for nearly two hours. The temperature had fallen still further, and my breath was clearly visible in the beam of my torch. The muffled acoustic quality that had troubled me earlier had become more pronounced, as though the building were swallowing every sound we made.

"Perhaps we should pack it in," I suggested. "We've documented plenty already."

Callum paused and looked at me.

"Since when have you wanted to leave early? This is exactly the sort of find that builds our reputation in the urban exploration community. A restricted area nobody else has accessed."

The lock clicked softly, and he smiled as he manipulated the picks with practised movements. I remained uneasy about the fresh warning, but I could not deny how much his lock-picking had improved over the years. He had progressed from clumsy fumbling to something approaching genuine skill.

"Besides," he continued, returning his attention to the lock, "whatever's behind here has been sealed for decades. The worst we'll find is more abandoned medical equipment and perhaps a few files they didn't want ordinary staff to see."

The deadbolt turned with a soft click that sounded unnaturally loud in the muted corridor. Callum pushed the outer door open.

I followed him into a maintenance room roughly 2.5 by 3 metres, with unpainted concrete walls and exposed pipes crossing the ceiling. The space felt cramped with both of us inside, but what struck me at once was the difference in temperature.

The room was warm.

It was not merely warmer than the corridor. It was genuinely comfortable, which made no sense given the condition of the hospital. I removed my gloves and raised my hands, feeling heat from a source I could not locate. The pipes overhead were cold when I touched them, and there was no obvious heating equipment.

"That's strange," I said, partly unzipping my jacket. "Where's the heat coming from?"

Callum was already inspecting a metal shelving unit fixed to the far wall, moving his torch across old supplies and tools.

"Residual heat from the boiler system, perhaps. Large old buildings sometimes retain warmth in odd places even after the main heating is switched off."

I was not convinced. The rest of Blackthorn had grown colder the deeper we went, and my breath had been visible in most rooms. Stepping into this place felt like entering another building altogether, one in which somebody had recently switched on a heater.

"Look at this," Callum said, with more excitement in his voice than I had heard all night.

I moved closer.

A hospital plan sat in a plastic sleeve on the shelving unit. It was far more detailed than anything we had found online. The plans Callum had shown me at the petrol station were rudimentary, but this one included precise room layouts, corridor measurements and utility lines throughout the hospital.

Most importantly, it showed the lower levels.

There was not merely one basement but several subfloors, distinguished by coloured markings and detailed room labels. I studied the plan in the beam of my torch, trying to reconcile it with everything I had learnt during the previous week. Every official document I had read described only a modest basement containing utilities and storage.

"This doesn't match anything I found at Derbyshire Record Office," I said, tracing the lower layout with my finger. "Look at the scale. There's almost as much space beneath the hospital as there is above ground."

Callum took out his mobile and photographed the plan several times, using the flash to capture details our torches might miss.

"The plans deposited for public access must have been simplified. This looks like an internal maintenance plan showing the real layout."

The lower levels were divided into distinct sections, and their labels made me increasingly uncomfortable. The eastern area contained a mortuary and what appeared to be refrigerated storage. The central portion was occupied by plant rooms and archive stores. To the west was a concealed section labelled "SPECIAL WARD", containing twelve rooms numbered SW-01 to SW-12.

I had never heard of a Special Ward in a psychiatric hospital. The fact that it lay apart from the ordinary patient floors, concealed beneath the western wing, suggested it had not been intended for routine care.

"Special Ward," I read aloud. "SW-01 through SW-12. What do you think that means?"

"Isolation rooms for patients needing closer supervision," Callum said, though his tone made it clear he was guessing. "Or experimental treatment rooms. Psychiatric care was very different in the 1980s."

The plan also carried coded notes around its margins, referring to utility systems, emergency procedures and staff access protocols. Most appeared to be ordinary institutional abbreviations, but several caught my eye because they resembled nothing I had encountered in my research into NHS hospital management.

"Look at these access codes," I said, indicating the markings beside the Special Ward. "Emergency lockdown procedure. Staff evacuation protocol. Containment system activation. This reads more like a prison than a hospital."

Callum examined the codes more carefully. His excitement grew as he grasped their implications.

"This is exactly what I meant. Official records only tell part of the story. The real history survives in documents like this, the ones that never reached the public archives."

At the rear of the maintenance room, I noticed another door. The shelving unit had partly concealed it until we moved closer to inspect the plan. It was made of thick metal, reinforced with brackets and fitted with several locking mechanisms. A faded sign read, "BASEMENT ACCESS - STAFF ONLY."

I counted five separate lock housings in the frame. Most had been cut or broken. Metal filings around them suggested that somebody had used power tools to force entry, probably years before, judging by the rust. Only one deadbolt remained intact, and its polished contact marks made it look as though it had been used recently.

"Someone's been down there," I said, examining the damage. "This isn't deterioration. Somebody deliberately cut through those locks."

"Previous explorers, probably," Callum replied, already taking the lock-pick set from his combat trousers. "Urban explorers have been active around here for years. It makes sense that somebody would eventually find this access point."

I stepped back from the inner basement door, properly frightened for the first time since entering Blackthorn. The fresh warning on the outer restricted-area door, the inexplicable warmth in the maintenance room and now evidence that someone had forced entry to basement levels that did not officially exist all pointed in a direction I did not like.

"Callum, we should pack it in," I said. I checked my watch and saw that we had been inside for more than two hours. "We've documented plenty. This is moving into territory we're not prepared for."

He looked up from the remaining deadbolt. His expression held the focused determination I had learnt to recognise over years of exploring with him. Once Callum decided to investigate something, logic rarely changed his mind.

"Are you joking? This is the discovery we've been working towards for two years."

He gestured at the plan in its plastic sleeve.

"Look at the discrepancies between this and everything we found online. The official floor plans show none of these lower levels, but this is detailed evidence that they exist."

I looked at the plan again, trying to understand why the records differed so completely. Buildings were altered over time, and changes were not always documented properly, especially in large institutions with complicated needs. Yet the basement plan seemed integral to the original structure rather than a record of later additions.

"Perhaps the files were deliberately incomplete," I said. "If they were carrying out controversial treatments down there, they might not have wanted detailed plans available in public records."

"Exactly."

Callum had selected two picks from his kit and was already working on the inner door's deadbolt. The other locks were older and bore the scars of having been forced years ago, but this one looked comparatively recent, its mechanism polished by use. Whatever lay beyond it could be evidence of practices concealed when Blackthorn closed. Psychiatric institutions in the 1980s had carried out procedures that would now be considered grotesquely unethical. His lock-picking had improved dramatically since our first explorations.

What had once taken him twenty minutes of fumbling now required only a few minutes of patient work. I watched him, feeling less certain by the second about going any deeper. The evidence suggested that we had stumbled upon something significant, exactly the kind of historical discovery that made urban exploration worthwhile. But my research into Blackthorn's closure had uncovered enough disturbing material to make me wary of areas deliberately sealed from public access.

"Think about it," Callum said, adjusting the angle of his pick to work around the deadbolt's internal mechanism. "We could be the first people to document whatever's down there since the official closure. This is the sort of material that ends up in urban exploration documentaries."

The lock clicked softly as the bolt retracted. Callum smiled, put away his tools and gripped the handle. Then he looked at me expectantly.

"You coming, or are you going to wait up here while I document the discovery of the decade?"

Against every instinct telling me that we had pushed our luck far enough for one night, I adjusted my camera bag and prepared to follow him into whatever lay below. Callum pulled the door open, and warm air flowed past us from the stairwell beyond.

The basement access opened on to a concrete landing, with steps descending into darkness. Our high-powered torches reached only a few metres ahead. I moved closer and aimed mine downwards, but the stairwell curved to the right after about ten steps, hiding the rest of the descent.

A mechanical drone rose from somewhere below, steady and rhythmic, as though machinery were operating by itself. The sound was strange. It was not quite electrical, but not entirely mechanical either. It reminded me of ancient equipment that had been running far beyond the point when anyone should have switched it off.

"Probably ventilation," Callum said, stepping on to the landing. "Buildings like this sometimes kept systems running to stop moisture damaging the lower levels."

The air rising from below was warm against my face. It carried a chemical smell that reminded me of hospitals, only sharper and more concentrated. It was not quite antiseptic, but something medical that had turned stale over time. I pulled my waxed jacket tighter despite the warmth, trying to identify it.

"Old cleaning supplies," I said, although that did not begin to describe it. "Maybe industrial disinfectant that's been sitting in containers for decades."

Callum was already descending. His torch beam bounced ahead as he tested each concrete step before trusting it with his full weight. His explorer's instincts had taken over completely, and I recognised the focused way he moved whenever a place captured his interest.

"I'll go first," he called back. "Stairwells can be dodgy in old buildings. Better to have someone who knows how to check for structural problems leading the way."

I stayed at the top and watched his light move steadily downwards, counting his footsteps as he passed around the curve. The mechanical drone continued below. Now and then I heard his boots scrape the concrete as he corrected his footing.

Fifteen steps. Twenty. Twenty-five.

The sounds of his descent gradually faded until I could no longer distinguish his footsteps from the noise filling the stairwell. His torchlight disappeared entirely beyond the bend, leaving me alone with the warm air and stale chemical smell rising from the darkness.

I waited for some indication of what he had found.

The drone seemed to alter slightly. It was not regular enough to be entirely automatic. At times it swelled for several seconds before subsiding again.

Three minutes passed, perhaps four. I checked my watch, trying to judge how long Callum should need to reach the bottom and begin examining whatever waited there.

"Callum," I shouted into the darkness.

My voice travelled down the stairwell, but the concrete walls seemed to swallow it, just as Blackthorn had swallowed every other sound that night. I waited for him to call back with his usual excitement about whatever he had discovered.

"Come down now."

His voice rose from below, but its tone stopped me at the head of the stairs. The words were flat, stripped of the excitement and curiosity that always coloured Callum's voice when he found something interesting. There was no inflection, no personality, only the sounds required to form the sentence.

"You all right down there?" I called.

"Come down now."

The same words returned with precisely the same timing and tone. They were not merely similar. They were identical, as if someone had recorded his voice and played it twice without changing a fraction of a second.

I stepped back from the stairwell, panic rising through me for the first time since we had entered the hospital. Something was wrong with the way Callum was answering. Wrong in a way that had nothing to do with unstable floors or abandoned equipment.

The mechanical drone grew louder. Its rhythm quickened, becoming harsher and more insistent.

Then, beneath it, I heard Callum scream.

The sound was raw with terror and pain. It carried up the stairs for several seconds before being cut off so abruptly that the silence afterwards felt like a blow.

His voice called again in the same blank tone.

"Help me."

The scream had sounded genuinely like Callum. The plea did not. Its absolute lack of emotion, and the way its cadence matched the earlier responses, made one thing horribly clear: whatever was calling to me from the lower level was not my friend.

I backed away, my hands shaking, as the flat voice repeated itself.

"Help me."

Nothing about it changed. It was a perfect copy played on a loop.

Then I heard the others.

Several voices spoke in unison from the darkness below. Every one of them had Callum's tone, inflections and vocal habits, layered together into a chorus of identical speakers.

"Come down now. Come down now. Come down now."

The drone rose until the concrete floor trembled beneath my boots.

Underneath that noise came footsteps climbing the stairwell. Not one person's tread, but several moving in perfect time, like a column marching upwards.

I counted as they drew closer.

Ten steps. Fifteen. Twenty.

Too many feet moved as one, striking the concrete simultaneously with every upward step. My torch shook in my hand as I retreated towards the maintenance-room door. Whatever was ascending was not Callum, and it was not human.

The chorus continued, adding phrases it had heard from us.

"You all right down there? You all right down there? Help me. Come down now."

Every word came in Callum's voice, assembled into a conversation that had never taken place. It was lifting pieces from our exchanges and repeating them as the footsteps climbed.

I ran.

I slammed the maintenance-room door behind me and sprinted along the corridor towards the administrative wing and the broken office window through which we had entered. My torch beam lurched wildly over fallen plaster and debris.

Behind me, the door burst open with tremendous force. Metal struck concrete in a crash that rang through the building. The footsteps followed at once, but they were no longer synchronised. They had become chaotic, like dozens of people running together. The noise filled the corridor and gained on me with every second.

Then the building itself began to change.

The corridor ahead was longer than it had been when we came that way. I recognised the water-stained walls and scattered plaster, yet the spaces between familiar landmarks appeared to have doubled. The nurses' station, which should have stood less than ten metres away, remained beyond my reach however quickly I ran.

Doors appeared where none had been before. Patient-room numbers contradicted the layout we had documented. Supply cupboards occupied positions that made no architectural sense.

My torch weakened as I ran, as though the darkness were consuming the beam before it reached the walls. I passed the same dented filing cabinet three times, with the same papers spilled across the floor in precisely the same pattern. A broken ceiling tile near the main junction repeated every few metres, multiplying ahead of me.

The temperature plunged. My breath clouded in sudden white bursts, and frost spread over the walls. Cold pierced my jacket and gloves until my fingers went numb around the torch. Behind me, the footsteps came closer.

I glanced over my shoulder and saw only darkness, yet the running continued, accompanied by a chorus calling my name.

"Jamie. Jamie. Come back, Jamie."

Every voice was Callum's, but each copy seemed to run at a fractionally different speed. They overlapped into a warped, churning mass of sound.

I reached a junction absent from the plans Callum had shown me. Three corridors branched in directions impossible within the building's rectangular footprint, each disappearing into total darkness. I chose the one that felt most familiar and prayed it would return me to the administrative wing.

The rooms along it had changed. The abandoned wards we had photographed, with their scattered belongings and decaying medical equipment, were gone. In their place stood rooms with fresh flowers in vases, beds made with crisp white sheets and personal possessions arranged as if the patients had stepped out only moments earlier. A warm glow filled each room, though I could not see its source.

My torch blinked twice and died.

I tried to open the battery compartment, but my numb fingers could not manage even that simple task. The light from the impossible patient rooms was just enough to keep me from walking into the walls.

The footsteps behind me stopped.

The silence frightened me more than the pursuit. I stood in the dark corridor listening to my breathing and the distant mechanical drone still rising from somewhere beneath the hospital.

Then Callum's voice spoke directly beside my ear, so close that I should have felt his breath against my neck.

"Where are you going?"

I bolted forwards, running almost blind with both hands outstretched. The patient-room glow allowed me to navigate, but it threw shadows across the corridor that moved independently of me.

At last, familiar landmarks appeared: the reception desk where we had found the ward diary ending abruptly on 22 December 1987, the overturned filing cabinets, and the office containing the broken window frame. I had never been so relieved to see ruin and decay.

The window was exactly as we had left it, roughly 1.2 metres above the floor, with no glass and only rotten wood around the opening. I hurled myself through without checking the ground beyond and struck the snow hard enough to empty my lungs.

Freezing air hit my face. I rolled away from the wall, staggered upright and looked back.

Every window in Blackthorn Hospital was dark and silent. No light shone inside. No sound escaped through the broken panes or gaps in the boards.

I ran towards the Scots pines where we had parked, my boots skidding on ice concealed beneath the snow. The distance seemed immense, far greater than the roughly 180 metres we had crossed earlier. My legs became heavy and uncertain, but I did not stop until I reached the trees.

Both cars were there: Callum's battered Ford Fiesta beside my ageing Vauxhall Astra. My keys remained in my pocket, and my camera bag was somehow still strapped across my chest after the escape.

I leant against the Astra, gasping in the freezing air and staring at the hospital.

From outside, it looked entirely ordinary. Its dark brick walls, boarded windows and collapsed stretches of roof appeared exactly as they had when we approached hours before. There was no sign of the chaos I had escaped, no suggestion that anything inside had shifted or pursued me.

My legs gave way, and I collapsed into the snow beside the car. The cold soaked through my combat trousers at once, but I could not find the strength to stand. Every muscle felt exhausted, as if I had run for hours rather than minutes.

I took out my mobile to call 999, report what had happened to Callum and bring a police search to the hill immediately. The screen showed no reception at all, despite the strong signal we had both had when we arrived.

Blackthorn's windows remained dark and empty. Even so, I felt something inside watching me, waiting to see what I would do next. Waiting to learn whether I would be foolish enough to return for my missing friend.

I knew I ought to go back for Callum. Every part of me understood that I could not leave him trapped with whatever had copied his voice and called from the stairwell. But my body refused to move towards the hospital. Some deeper instinct had taken control, holding me in the snow rather than allowing me to approach that building again.

The mechanical drone continued, so faint that I might have imagined it, drifting across the white ground from Blackthorn Hill.

My head hurt as if I had been unconscious for hours. When I opened my eyes, the glare above me made me regret it immediately. I tried to work out where I was and why every part of my body ached.

White ceiling tiles. Antiseptic and floor cleaner. Machines beeping steadily nearby.

A hospital room, clearly, but not the abandoned one through which I had been running. This place was clean, functioning and very much occupied. I attempted to sit up, then abandoned the effort. My muscles felt as though I had been struck by a lorry, and the room spun until I lay back on the narrow bed.

Through the window, I could see Millcombe spread across the Derwent valley. I was in Millcombe District Hospital on the southern edge of town.

A middle-aged police constable sat in a plastic chair near the foot of the bed, writing in a small notebook. When I moved, he looked up. His expression was professional without being unfriendly.

"Mr Mercer, I'm PC Daniel Hargreaves, Derbyshire Constabulary. How are you feeling?"

"Awful," I said. My voice was rougher than I expected. "What happened? How did I get here?"

PC Hargreaves rested the notebook on his lap and leant forwards.

"We were hoping you could tell us. Martin and Ruth Wilkes found you unconscious in a snowbank beside the A515 at 06:30 this morning, Saturday, 16 December. They were on their way to work when they spotted you, nearly a mile from Blackthorn Hill."

I stared at him. I remembered reaching the cars and collapsing in the snow, but the A515 was nowhere near where we had parked. I could not have covered that distance, certainly not in my condition.

"I was beside my car," I said slowly, trying to piece together what had happened. "Behind the pines near Blackthorn. Callum and I parked there before we went inside."

Hargreaves lifted his pen again.

"Tell me about Callum. When did you last see him?"

The question brought everything back at once: Callum disappearing down the stairs, his voice rising from the darkness, and the pursuit through corridors that stretched and repeated around me.

I told him the whole story, from meeting Callum at 20:30 on Friday, 15 December, on the petrol station forecourt at the edge of Millcombe, to my escape through the office window. He wrote steadily, occasionally interrupting to clarify a time, location or detail. I explained the concealed plan and the rooms marked SW-01 through SW-12. I described the outer restricted-area door with its relatively modern deadbolt and the fresh warning, "DO NOT OPEN. IT KNOWS YOUR VOICE." Then I described the inner basement door, with its old, broken locks and the one deadbolt that appeared recently used.

When I finished, he put down his pen and studied me.

"Mr Mercer, I need you to understand something. Officers searched the site after we were notified of your condition. They found your Astra near the hill, but there was no sign of Mr Vane or his Fiesta. There were no footprints around the building and no evidence of forced entry through any door or window. Blackthorn has been sealed for safety, and all known access points were secure."

"What about the south-side window?" I asked. "The office window with the missing glass. That's where we climbed through."

"Every ground-floor window is boarded. The boards show no recent damage or removal."

He consulted his notes.

"You also described a maintenance room and basement access. Neither appears on the plans available to us. Official records state that the hospital's lower levels were pumped full of concrete in March 1996."

The words struck harder than the cold had. Everything I remembered with absolute certainty apparently did not exist: the warm maintenance room, the laminated plan, the inner door with its defeated locks, and the stairwell descending into darkness.

"That's impossible," I said. "I was there. I saw the plan. It showed a mortuary, plant rooms, archive stores and a concealed treatment section. The Special Ward. SW-01 through SW-12."

Something shifted behind Hargreaves's neutral expression, perhaps concern, perhaps doubt.

"There is a verified history of abuse at Blackthorn," he said carefully. "The original infirmary opened in 1911, and the secure psychiatric wing was added in 1936. An official inquiry in 1987 found serious failures in patient care, and the regional health authority closed the hospital after its authority to operate was withdrawn. Some surviving records do refer to treatment spaces on lower levels. But those areas were sealed long ago, and nothing found during this morning's search supports the route you've described."

"So the basement did exist."

"Parts of it did. That doesn't mean they can be entered now."

He closed his notebook.

"When you're medically fit, we'd like you to accompany us back in daylight. It may help us establish where you were and what happened."

The visit did not take place until the doctors were satisfied that the hypothermia and exposure had not left me at immediate risk. By then, the council's estates department had authorised access and supplied keys. PC Hargreaves drove me up the winding road to Blackthorn Hill.

The building looked as it had on Friday night: four storeys of dark Victorian brick standing above Millcombe town centre and the Derwent valley, its windows boarded and parts of its roof collapsed.

We walked to the south side. Every window was covered. The timber looked old and weathered, with no sign that anyone had disturbed it recently.

"This is where we went in," I said, pointing to a window indistinguishable from the others. "There was no glass, and the frame was rotten."

Hargreaves examined the boards and ran his fingers along their edges.

"These haven't moved in years. The nails are rusted solid, and the timber has weathered evenly."

He unlocked the main entrance with the council keys. Inside, the administrative wing resembled the place I remembered, but small details were wrong. The office through which we had climbed possessed an intact window behind boards securely fixed from within. The reception area contained scattered papers and overturned furniture, but nothing lay where I remembered it.

When we reached the corridor where the maintenance room should have been, Hargreaves unfolded the authorised building plan. The passage ended at a plain brick wall.

No room occupied that position on the official layout. The wall itself was solid, with no lintel, seam or other evidence that a doorway had ever existed.

"The access you described isn't possible from here," Hargreaves said, tapping the plan. "This was built as a single-storey extension. There is no lower level beneath this section."

I stared at the brickwork, trying to reconcile it with my vivid memory of the warm room, the laminated basement plan and Callum bending over the deadbolt. Everything I remembered happening in that exact place was physically impossible.

Standing in the corridor, surrounded by evidence contradicting every recollection, I understood why the police had found no trace of Callum.

According to the building in daylight, we had never entered it at all.

On Friday, 5 January 2024, exactly three weeks after Callum vanished, I traced a finger along the edge of his missing-person appeal for what must have been the hundredth time. The paper had softened from handling and was creased where I had folded and unfolded it during sleepless nights, taking it out simply to confirm that the words remained.

Callum Vane, aged 24, last seen on Friday, 15 December 2023.

The report from Derbyshire Constabulary lay beneath it, its formal language making everything sound clinical and settled. The active missing-person inquiry had been suspended. There was no evidence supporting the circumstances I had reported, and my account was attributed to a psychological episode caused by hypothermia and prolonged exposure.

PC Hargreaves had remained professional when he explained the decision, but I recognised the guarded sympathy in his eyes. It was the look people gave someone they believed had lost his grip on reality.

My flat felt smaller than before. I spent most of my time there, avoiding university and the questions of people who had heard what happened. News travelled quickly through Millcombe, especially when it involved Blackthorn Hospital and a man found half-frozen beside the main road.

The private investigator's report had arrived the previous day. Helen Vane had hired him after the police suspended their active inquiry, desperate to learn what had happened to her son. His three pages of methodical findings were thorough and bleak in their simplicity.

Callum had told his flatmate on Friday afternoon that he was going urban exploring. He had packed his camera equipment and lock picks as usual. Then he had disappeared.

No one else could confirm seeing him that night. No road or petrol-station camera had reliably recorded his Fiesta travelling towards Blackthorn. His bank cards had not been used. His mobile had gone straight to voicemail since Friday evening. His online accounts had fallen silent around the time he was meant to have called me about the expedition.

His Fiesta had vanished with him. Only my Astra had been recovered near the hill.

I read the investigator's timeline again and again, searching for a gap where Callum's movements might have escaped notice. But the man was competent, perhaps too competent. He traced Callum until Friday afternoon and then found nothing. There was no evidence of where he went or what he intended to do that evening.

The disconnect between my memories and the documented facts had been eating at me for weeks. I could recall every detail of the night: Callum's excitement as he spread the plans across the bonnet of his Fiesta, the movement of his torch over Blackthorn's brickwork, and the soft clicks of his picks inside the deadbolt.

My camera offered no help. The memory card had been corrupted. A technician recovered only a handful of exterior photographs taken before we approached the hospital, none showing Callum, either car or anything that proved we had entered.

According to everyone else, none of it had happened.

I began questioning everything: our conversations about Blackthorn, the research I had done before the expedition, even Callum's telephone call on Tuesday, 12 December, when he first told me he had found a way inside. Perhaps I had imagined it all during some kind of breakdown, constructing an elaborate story to explain why I woke beside the A515.

But the timing did not fit.

If I had suffered a psychological break, when had it begun? The week before Friday remained full of ordinary interactions and routine work. A lecturer had complimented my latest photography assignment on Thursday. I had eaten lunch with my flatmate earlier in the week. Nothing had felt unusual until Callum's call.

What troubled me most was not the missing evidence or the sceptical looks. It was my certainty that the thing calling from the basement had not been Callum.

I replayed those moments hundreds of times, analysing every detail. Callum's voice saying, "Come down now," in that flat, emotionless tone. The repetition had been exact, not merely close, but perfect in the manner of a recording. People did not speak like that, least of all Callum, who had never delivered the same sentence identically twice in all the years I had known him.

The scream was different. That had been genuine, filled with terror and pain. But the pleas afterwards contained nothing. They were mechanical reproductions of his speech, without the slightest understanding of the words.

Late at night, when the flat was quiet, I sometimes heard the same voice call my name from outside. It drifted through the windows, faint but unmistakable, using exactly the tone and pronunciation Callum would have used.

The first few times, I rushed to the glass, believing he might have escaped and come looking for me. Yet the voice never came from any fixed direction. It seemed to rise from the darkness itself, passing over the car park and neighbouring streets without a visible source. If I called back to ask where he was or whether he needed help, it repeated my name once and then stopped.

I kept the windows shut and locked after that. The resulting heating bill was becoming unaffordable, but the sound still seeped through, muffled and persistent. It always came between midnight and dawn, when rational explanations were hardest to hold on to.

My research into Blackthorn consumed most of those three weeks. At Derbyshire Record Office, I found newspaper reports, Department of Health and Social Security inquiry files and surviving regional health authority records. Together they revealed far more than PC Hargreaves could reasonably have told me at my bedside.

Complaints from the 1960s and 1970s described appalling conditions in the psychiatric wing. Patient advocates had repeatedly challenged the hospital's treatment practices. Inspectors later documented unauthorised experimental procedures, systemic abuse and deaths that had never been adequately explained.

References to the lower treatment areas appeared throughout the documents, despite the official claim that those levels had been filled with concrete in March 1996. Internal memoranda consistently called the concealed section the Special Ward. Its twelve rooms were numbered SW-01 through SW-12, exactly as they had been on the laminated plan I saw that night.

Staff reports discussed containment protocols and subject-preparation procedures in language closer to a prison regime than medical care.

The most disturbing evidence lay in patient testimony sealed under a High Court order and only partly released in later records. Several patients described voices in the Special Ward. They claimed something there could imitate any person's speech with perfect accuracy. Familiar voices called them deeper into the lower levels, pleading for help from empty rooms or from spaces where no human being could have stood.

Dr Eleanor Pryce had taken a particular interest in the reports. Her notes argued that the patients were experiencing shared hallucinations caused by trauma and the stress of their treatment. Yet several members of staff had reported the same phenomenon. They described voices copying patients and colleagues with impossible precision.

The official inquiry ended with Blackthorn's closure in 1987, when its NHS authorisation and regional health authority approval were withdrawn. Staff dispersed to other institutions, and many patient files remained sealed. Dr Pryce disappeared after the closure. General Medical Council records contained no useful forwarding address or later place of practice.

I tried to trace former employees named in the reports, but most had died or moved away decades earlier. Those I reached by telephone usually ended the call when I mentioned the Special Ward.

One retired staff nurse spoke to me briefly. She had worked at Blackthorn from 1974 to 1981 and remembered the voice incidents clearly. She said they grew more frequent before she left, with patients and staff describing identical experiences involving flawless imitations of people they knew.

"It started downstairs," she told me before ending the call. "Whatever was there learnt to sound like anyone it wanted. Management explained it away, but we knew something was wrong. Some buildings collect darkness. Blackthorn had been doing it for years."

The hospital still stood above Millcombe, officially empty but never truly abandoned. I drove past it several times during those three weeks, always in daylight, when the rational part of my mind could maintain control.

It looked exactly as it had on the night we went inside: dark brick, boarded windows and no outward sign of change. But I could never shake the feeling that something waited within.

Perhaps it was calling to other explorers in voices they knew and trusted. Young people hungry for adventure would be drawn by the same stories that had attracted Callum and me. Blackthorn's reputation as a haunted hospital would only bring more of them into danger. They would dismiss every warning as a local tale until it was too late.

Callum was still missing. He had not been declared dead, had not moved away and was not hiding somewhere while he recovered. His flat, belongings, family and records proved that he had existed. Helen's grief proved it. Yet Blackthorn offered no physical evidence that he had ever crossed its threshold.

I folded the missing-person appeal and returned it to the folder with everything else: police reports, the investigator's findings, hospital plans, inquiry files and newspaper cuttings. Together they formed a paper trail proving that something had happened, even if no one could agree what it was.

The next day, I would probably drive past Blackthorn again. I would not go inside or attempt another search. I only needed to see that it remained on the hill, waiting for the next curious people to ignore the warnings and enter places that should have stayed sealed.

Whatever had taken Callum was patient. It had waited below the hospital for decades, learning to reproduce human voices and lure people deeper into forgotten rooms. It could wait longer. It would call in voices familiar to anyone foolish enough to listen and answer.

The voice outside my window had been silent for three nights, but I knew it would return.

It was practising Callum's voice. Each time, it sounded a little more like him. Soon it might reproduce him so perfectly that even I would believe my friend had found his way back from the darkness beneath Blackthorn Hospital.

And when it finally got every breath, hesitation and flicker of feeling right, it would ask me to come back.