The Thin Place Below

The helicopter's rotors slowed as we settled on the helideck. After three hours of rough air from Aberdeen to the northern North Sea, east of Shetland, my legs felt unsteady when I climbed out. The offshore installation spread before me, an immense industrial complex rising from black water beneath a ceiling of low cloud. In fifteen years of working on rigs, I had never seen anything so large.

It occupied roughly four times the footprint of an ordinary North Sea installation. I collected my holdall and walked towards what appeared to be a processing station. Two men carrying carbines blocked my path. Their faces were blank and professional. They belonged to the specialist armed security unit mentioned in the contract paperwork, but the weapons still looked startling on a British offshore installation.

The guns were not for show.

"Identification and authorisation."

The taller man held out his hand. I produced my credentials and transfer papers.

"Edward Mercer. New senior drilling engineer."

The guard checked the documents with a handheld reader, then studied my face, comparing it with whatever appeared on his screen. His colleague kept his attention on the horizon rather than on me. That was strange. On most installations, security watched whoever was coming aboard, not the surrounding water.

"Clear."

The first guard returned my papers.

"Follow the white-and-green markings to processing."

I followed the painted deck markings through corridors fitted with access-card scanners and cameras at every turn. It was excessive for an offshore energy installation. The place felt more like a secure laboratory or military facility. Steel doors with different clearance ratings stood everywhere, many bearing signs that read, "Authorised personnel only."

At processing, a woman sat behind ballistic glass. She took my fingerprints and scanned my irises before issuing an access card without looking directly at me.

"Level two clearance," she said. "Do not try any door marked level three or above."

I nodded and took the card. She also inspected my company-issued mobile, confirmed that it was locked in offline mode and returned it to me. Senior engineers were permitted to keep one for technical photographs and maintenance records, provided its wireless functions remained disabled.

"Who do I report to?"

"Installation manager Graham Strickland. East wing, operations." She pointed along another corridor. "Follow the white-and-green markings."

Graham Strickland was a hard-looking man in his mid-forties, with short grey hair and the straight-backed bearing of someone with a military background. He barely glanced up from his tablet when I entered his office.

"Mercer," he said. It was not a question. "Your credentials are impressive. Calder rigs, the North Sea, Kazakhstan. Why did you accept this posting?"

The question caught me off guard. Most managers did not care why you took a contract, only whether you could do the work.

"More than twice the pay of my last contract," I answered honestly. "And curiosity. The job description did not say much beyond specialised extraction techniques."

Strickland's eyes narrowed slightly.

"We value discretion here. Your contract contains an extensive non-disclosure agreement for a reason." He looked back at his tablet. "You'll share quarters with Callum Price. He's been aboard for three years, after two years at other installations. He'll show you the accommodation deck. Tomorrow at 06:00, you'll receive your full briefing and assignment. Questions?"

"What exactly are we drilling for out here?" I asked, testing him.

Strickland looked up, his face without expression.

"Hydrocarbons, Mercer. What else would we be drilling for?"

Something in his tone told me not to push. Not yet.

"No other questions."

"Good. Price will be in the canteen. East wing, deck three."

I followed more white-and-green markings to the canteen, a modern room with proper windows overlooking the sea. Most offshore facilities I had worked on had hardly any windows, but one entire wall here was glass. The food smelt better than anything I had encountered on a rig as well.

The canteen was about half full, with perhaps thirty people eating their evening meal. I collected a tray of fresh roast lamb, potatoes and greens instead of the usual reheated fare, then looked for somewhere to sit.

"You must be Mercer."

I turned towards the voice and found a man in his early thirties watching me with guarded eyes. He wore the same company-issued coveralls as everyone else, but carried himself differently. He seemed alert to every movement in the room, constantly assessing the people around him.

"Callum Price," he said, extending his hand. "I'm your bunkmate."

His handshake was firm but brief, almost reluctant. He indicated an empty table away from the others.

"How long have you worked offshore?" he asked once we were seated.

"Fifteen years. Started as a roughneck after university and worked my way up. What about you?"

"Two years at other sites, then three here. I work mainly on the eastern deck. Technical systems."

His answers were clipped and efficient.

I tried the lamb. It was perfectly cooked, nearer restaurant food than rig catering.

"The food is better than anywhere else I've worked offshore."

Callum nodded.

"The company believes in keeping people comfortable. The contracts are long. Six months on, three weeks off."

That was alarmingly long beside a normal North Sea rota. Most crews worked two or three weeks offshore, followed by a comparable period at home. Six months sounded less like a rotation than a sentence.

A quiet instrumentation technician sat alone at the next table, slowly eating whilst studying figures on a tablet. I had noticed him during processing because he avoided looking at the windows. The name strip on his coveralls read ASHDOWN.

Callum caught me glancing at him.

"Peter Ashdown," he said. "Instrumentation. Keeps to himself."

Peter looked up at the sound of his name. I introduced myself, and he gave me a distracted nod before returning to his figures.

Two other men approached our table. The older one nodded to Callum.

"This the new engineer?"

Callum nodded.

"Edward Mercer, meet Martin Hargreaves and Neil Bancroft. Martin runs production deck two. Neil is the senior technician."

Martin looked to be in his mid-thirties and moved with the confidence of someone who considered the place his own. Neil seemed slightly older, perhaps in his late thirties, with sharp eyes that missed very little.

"Welcome aboard," Martin said as he sat down. "How was the flight out?"

"Long. I saw a great deal of empty sea."

"You become accustomed to the isolation," Neil said, picking at his food.

His gaze kept moving towards Callum, then back to his plate.

"What are the production figures like?" I asked casually. "The briefing material was rather light on detail."

Martin and Neil exchanged a quick look. Something passed between them, perhaps a warning.

"Standard deep-water extraction," Martin said carefully. "You'll receive the full specifications tomorrow."

"We're meeting targets," Neil added. "That's the important thing."

I tried another approach.

"What about the drilling depth? Are we talking deep or ultra-deep?"

The table fell quiet. Even Callum seemed to tighten beside me.

"All operational details are covered in the morning briefing," Neil said at last.

His tone was polite but firm. The subject was closed.

The rest of the meal passed in small talk about Aberdeen FC, the Scottish Premiership and whether the satellite television reception would hold long enough to show the weekend football. Whenever I tried to discuss the installation or its work in any detail, they became vague or changed the subject.

They were hiding something, and they were not making much effort to disguise it.

After dinner, Callum led me to our quarters on the accommodation deck. The cabin was larger than a standard offshore room, with two decent beds, a small sitting area and an en-suite shower room with genuine water pressure. Like the canteen, it had a window. This one faced west, towards the last bruised light beneath the clouds.

"Lights out is recommended at 22:00," Callum said. "It isn't compulsory. Just don't make a racket if you stay awake."

He pointed to a panel on the wall.

"That's the communications system. Blue button for general announcements, red for emergencies. Don't touch the amber sealed button."

There was no label on the amber button.

"What does it do?"

"You don't have the clearance to know," he replied at once. "So don't touch it."

Callum chose the bed furthest from the door and took out a tablet. Our conversation was clearly finished.

I unpacked my holdall, stowed my belongings and took a shower. When I came out, Callum appeared to be asleep with his back to the room. I lay down but could not settle. The sounds of the installation were wrong.

I knew the usual noises of an offshore structure: metal creaking under strain, the distant throb of generators, waves striking the support columns. This place had all of them, but beneath them lay something else. A rhythm that seemed to rise from far below.

It did not sound mechanical. It was slow and steady.

I got up and went to the window. There was no moon, and only the installation's lights broke the darkness of the northern sea.

The water looked wrong. The powerful lamps should have painted the nearby waves with broken reflections, but the surface seemed to swallow the light instead. Nothing came back.

It formed a circle of darkness around the installation, as though the black water were soaking up every trace of illumination. As I watched, the pulse grew louder. It was not merely inside my head. Something beneath us, deep below the seabed, was making that rhythm.

Something vast.

I moved closer to the glass, trying to understand what was wrong with the darkness. For a moment I thought I saw something moving through the water. Not a wave, but a solid shape travelling with purpose.

Then it vanished.

Behind me, Callum's voice broke the silence.

"Don't look at the water for too long."

So he had not been asleep.

"It's against installation protocols."

I turned from the window.

"Why?"

In the dimness, I saw him sitting upright in bed.

"You should sleep. The morning briefing is early, and you'll need to be sharp."

He turned to face the wall again. I returned to my bed.

I lay awake in the darkness, listening to that unnatural rhythm below and wondering what was really happening here, and why no one would speak of it.

I barely slept. The pulse from beneath the installation kept me awake, along with the memory of that dark circle in the sea which reflected no light. Every time I closed my eyes, I pictured it widening around us.

Callum said nothing more after warning me away from the window, and I did not press him. When my alarm sounded at 05:30, I felt as though I had been struck by a lorry. Callum was already dressed and sitting on the edge of his bed, waiting.

"You look dreadful," he said.

"Thank you." I rubbed my face. "Is the coffee any good, at least?"

"Better than you'd expect. Get some on the way to the briefing."

I showered quickly, trying to clear the fog from my mind. The water pressure remained surprisingly strong. As I pulled on my company-issued coveralls, I caught Callum watching me in the mirror.

"What?"

"Nothing. Let's go. Strickland dislikes lateness."

The canteen was busy with the morning shift collecting breakfast. I filled a large insulated flask with coffee that smelt better than anything I had drunk offshore. Callum led me through a succession of corridors to a large conference room where roughly twenty people were already seated.

Strickland stood at the front, scrolling through his tablet. He looked up when we entered and made a point of checking his watch.

"Five minutes," he told the room.

I found an empty chair beside Martin, who acknowledged me with a nod. The coffee tasted as good as it smelt, dark and strong. As I took another drink, Strickland put down his tablet and faced us.

"Morning briefing," he announced without preamble. "Before assignments, a reminder of our unique operating parameters."

He pressed a control and the lights dimmed. A digital cross-section of the installation, the sea and the strata beneath the seabed appeared on the wall behind him.

"For our newest team member," Strickland continued, looking directly at me, "and as a refresher for everyone else, this installation occupies what the company designates an anomaly pocket. Standard physical behaviour can become unpredictable here. That is why our protocols extend beyond normal offshore health and safety procedures."

My fatigue disappeared. In fifteen years of offshore drilling, I had never heard anything like it. Martin must have noticed my reaction because he gave a minute shake of his head, warning me to remain silent.

Strickland touched his screen and the display changed to a list of rules.

"Rule one: no extended observation of the surrounding water. Thirty seconds maximum. This is not superstition. It is based on documented incidents."

He worked down the list.

"Rule two: no physical contact with seawater. If you drop anything overboard, report it. Do not attempt to retrieve it.

"Rule three: maintain continuous radio contact during all exterior work. If communications fail for more than sixty seconds, emergency procedures activate automatically.

"Rule four: report any unusual sighting immediately. Do not investigate it yourself."

Neil raised a hand from the other side of the table.

"Sir, regarding rule four, what qualifies as an unusual sighting?"

Strickland's face tightened.

"You know company policy on specifics, Bancroft. If you see anything that does not belong on an offshore installation or in the northern North Sea, report it."

The non-answer hung in the room. I studied the faces around me. No one appeared surprised by Strickland's evasion. They knew something I did not.

"Moving to today's assignments," Strickland continued. "Mercer, you're with Hargreaves on the eastern production deck. He'll show you our systems. Price, monitoring station three. Bancroft, continue calibration of the southern sensors. Everyone else, consult your tablets."

He dismissed us with a nod.

As people filed out, I caught fragments of conversation about pressure readings, equipment checks and shift times. Even after that extraordinary briefing, they sounded like ordinary offshore workers preparing for an ordinary day.

Martin tapped my shoulder.

"Ready for the tour?"

I followed him along more corridors to a lift. He scanned his access card and we descended.

"An anomaly pocket," I said as the lift hummed downwards.

Martin sighed.

"I know how it sounds, but strange things happen here. Follow the rules and you remain safe."

"What sort of strange things?"

The lift stopped. Martin stepped out without answering.

We entered a vast open area filled with drilling equipment: the eastern production deck. It resembled any advanced offshore operation, with control stations, banks of monitoring screens and heavy machinery. The familiar equipment was almost reassuring after everything else I had encountered.

"This is east production," Martin said. "One of four principal drilling sections. Your station is over here."

He led me to a control console overlooking the main drill shaft. The equipment was sophisticated, but it operated on principles I understood completely: pressure gauges, temperature monitors, torque readings and drill-string data.

"Your job is straightforward," Martin said. "Monitor these systems, maintain the optimum drilling parameters and report any anomaly directly to me or Strickland."

I ran my hands over the controls, feeling at home for the first time since my arrival.

"What's our present depth?"

"Twelve thousand four hundred and ten metres, and descending."

I looked up sharply.

"That's beyond what should be achievable with existing technology."

Martin's expression did not change.

"As Strickland said, anomaly pocket."

He showed me the modified safety systems: additional emergency cut-offs, redundant monitors and evacuation routes marked on every wall. Each workstation had a direct connection to security and medical personnel.

"This seems excessive for an energy installation," I said.

"Better to have it than need it."

Martin indicated several screens displaying underwater footage.

"These monitor the area around the support columns. If you see anything unusual, press the blue button."

The feed showed an apparently normal seabed around the enormous supports, but the image quality felt wrong. It was far too clear for underwater footage at that depth.

"What powers these cameras? The resolution is extraordinary."

"Proprietary technology," Martin said, employing what I soon realised was his standard answer to anything unusual.

We continued across the production deck. I noticed small details that did not fit: equipment modifications intended to defend against something beyond ordinary industrial hazards, abnormal reinforcement along every barrier beside open water, and symbols on certain doors which belonged to no safety code I recognised.

At about midday, Martin led me back to the canteen for lunch. I saw Callum sitting alone and joined him after collecting another tray of improbably good food.

"How was the tour?" Callum asked.

"Informative," I said, keeping my voice neutral. "Good equipment."

Callum moved his food around his plate.

"Did they give you the anomaly-pocket speech?"

"Yes."

"Do you believe it?"

"It doesn't matter what I believe. Rules keep people alive."

He lowered his voice.

"Crew turnover is high here. People are transferred without warning or explanation. Last month, five disappeared overnight."

I thought of the armed guards, the excessive security and the warnings about the water.

"Transferred where?"

Callum shrugged.

"Caledonian Deep Energy has facilities throughout its network. Some people volunteer for transfer after a few months. Others..."

He stopped, then forced a change of subject.

"The food is good, though, isn't it?"

After lunch, Martin continued the tour until our shift ended. By evening, my head was crowded with everything I had seen and been told. The installation violated so many accepted industry assumptions, and the explanations sounded absurd: an anomaly pocket in which physics worked differently.

It belonged in a science-fiction film.

Back in the cabin, I showered and changed. Callum was absent, so I had the room to myself. I went to the window, keeping careful track of the seconds.

Beyond the glass, guards patrolled the exterior walkways. Every one of them watched the water with a carbine held ready. They were not defending the installation against people trying to board. They were waiting for something to emerge from the sea.

Movement appeared on the horizon. A compact vessel covered in bright lights was approaching from the south-east. It was not one of the Aberdeen supply ships. It was smaller, with equipment crowded across its deck, and looked like a survey vessel.

I watched it draw nearer and wondered what sort of survey work could be required at such a place. Callum returned as I stepped back from the window.

"There's a survey vessel coming in," I said casually.

He glanced towards the glass and then at me.

"They come and go. It's part of the operation."

"What sort of operation needs drilling crews and scientific researchers?"

Callum did not answer. He prepared for bed in silence, and I followed his example.

That night, the pulse from below seemed louder and more insistent. I lay awake for hours, listening to it and thinking about the lightless water and the guards staring at the waves.

By morning, the survey vessel had gone. As we walked to breakfast, however, I saw sealed sensor frames being unloaded and arranged across the southern deck. None of the equipment had been there the previous day.

The rota changed sooner than I expected. After only three days aboard, I was assigned to a night shift on the eastern production deck. The reassignment was too abrupt to feel like ordinary staffing. One moment I was finishing lunch in the canteen; the next I was watching the day crew depart as I settled in for twelve hours alone. I began to suspect that Strickland was moving me between stations deliberately, either to watch my reactions or to expose me to particular parts of the operation.

The eastern deck felt different at night. Daytime activity gave way to a peculiar quiet broken only by the drilling machinery. With most of the crew gone, the immense production area seemed larger still. My footsteps echoed through the empty space as I made my rounds.

I spent the first few hours checking pressure readings and monitoring the equipment. The figures remained irritatingly stable despite the depth of the eastern bore section. According to the log, it had reached 12,427 metres, an impossible depth by conventional standards. Each time I considered the number, Martin's explanation returned to me.

Anomaly pocket.

The night dragged. At 02:00, I made a circuit of the deck interior, recording maintenance checks and searching for faults. Being alone gave me time to consider everything I had seen since arriving: the armed security, the unnatural darkness in the water, and the sealed sensor equipment on the southern deck which no one would discuss.

By 03:00, the silence had become oppressive. I returned to the monitoring station and poured more coffee from my insulated flask. It tasted far better than any drink had a right to taste on an offshore installation. I recorded the hourly readings and saw that the eastern instrument had advanced several metres.

The drilling never stopped. The drill string maintained its relentless descent into whatever waited below.

At precisely 03:17, a human scream tore through the machinery's noise.

I sprang upright and knocked my coffee across the console. The scream came again, raw and terrified, from the lower deck.

I seized my radio.

"Mercer on east production. Screaming from the lower deck. Does anyone copy?"

Static crackled before Strickland answered.

"All personnel remain at their stations. Security is responding."

My hand stalled on the radio. The screaming continued, joined now by shouts.

Standard procedure required me to remain where I was during an emergency unless specifically ordered to assist. I headed for the stairs.

Taking them two at a time, I raced down to the exterior walkway encircling the lower deck. The screams grew louder as I forced open the heavy door. Wind and freezing spray struck me like a wall.

The scene outside stopped me.

Three security officers surrounded a worker near the railing. I recognised Owen Talbot, a roughneck from the drilling team. He lay on his back, clawing at the steel deck, his face contorted with terror. Two guards gripped his arms and tried to drag him away from the edge, whilst a third aimed a pneumatic line-launcher towards the water. The weapon had been modified to fire a barbed containment bolt.

"Hold him!" one of the guards shouted into the wind.

Owen's body was wrenched towards the sea with such force that one guard stumbled. His boots scraped across the deck, leaving long marks on the metal. Both men hauled against whatever had him, the strain plain on their faces.

"What's happening?" I shouted, moving to help.

One of the guards turned towards me.

"Get back inside!"

Before I could respond, the officer with the line-launcher fired. The bolt struck the water with a violent splash. The sea around it began to bubble and churn as a dark mass shifted below the surface. It was not a shark or any marine animal I had ever seen, only something darker moving inside the already black water.

Owen screamed again. His body jerked, and one guard lost his grip. The remaining man could not hold him alone. Owen slid towards the railing as if he had suddenly become weightless.

One final pull lifted him completely from the deck and carried him over the edge.

He entered the water without a splash. The surface simply accepted him.

Then everything stopped. The churning vanished, and the sea became flat and calm, as though nothing had occurred.

"Man overboard!" a guard shouted into his radio. "Eastern platform, lower deck!"

More security personnel arrived within seconds. Strickland ran up beside me, breathing hard.

"Get inside," he ordered, his voice flat and cold. "Lockdown procedures are now in effect."

I could not move.

"What took him? That wasn't normal."

"Inside. Now."

Strickland gripped my arm and pulled me towards the door.

"All personnel, return to quarters immediately. This is not a drill."

His order travelled throughout the installation over the Tannoy system. Guards took positions at junctions and ensured that everyone moved towards the accommodation deck.

As they escorted us through the corridors, I heard fragments of radio traffic: search teams assembling, boats being lowered, sectors assigned for sweep patterns.

Callum was already in our cabin when I arrived. He sat fully dressed on his bed and displayed no surprise at the lockdown.

"What happened?" he asked, his voice carefully neutral.

"A roughneck named Owen was pulled overboard by something in the water."

I paced the cabin.

"The guards couldn't hold him. It was as though he were caught on a trawler cable, except there was nothing to see."

Callum closed his eyes for a moment.

"Christ," he whispered. "Not another one."

"Another one?"

I stopped pacing.

"This has happened before?"

He glanced towards the corners of the room, then up at the ceiling.

"We can't discuss it. Not here."

The warning in his eyes was unmistakable.

We sat in strained silence for hours. The lockdown remained in force, with regular announcements instructing all non-essential personnel to stay in their quarters.

At 07:43, the Tannoy sounded again.

"Attention, all personnel. Lockdown procedures have been lifted. Day shift may proceed to normal duties. Night shift will remain on extended duty until further notice."

Callum stood.

"They found him," he said flatly.

"How do you know?"

"They always do." He went to the door. "Come on. Breakfast."

The canteen hummed with nervous energy. Voices dropped to whispers whenever anyone approached. Strickland entered after nearly everyone had gathered and moved to the front.

"Attention."

The room fell silent.

"At 03:17, crew member Owen Talbot suffered an epileptic seizure whilst working on the eastern platform. During the medical event, he fell overboard. Following an extensive search, Mr Talbot was recovered approximately three nautical miles from the installation. He is alive and receiving medical attention. He will be flown to Aberdeen Royal Infirmary later today."

I nearly choked on my coffee.

An epileptic seizure. It bore no resemblance to what I had witnessed.

I searched the room for anyone willing to challenge the lie. Most faces remained carefully blank, their owners intent on their breakfast.

"Normal operations will resume immediately," Strickland continued. "Additional safety briefings on correct railing procedures will be scheduled. That is all."

As soon as he left, the low murmur resumed. I saw Martin and Neil at a nearby table and joined them, with Callum close behind.

"That isn't what happened," I said without introduction. "I saw all of it. Something pulled Owen into the water. He was dragged across the deck by some kind of force."

Callum kicked me hard in the shin beneath the table. Martin and Neil exchanged a look.

"Mercer," Martin said quietly, shaking his head. "Owen suffered a seizure, lost his balance and fell. That is what happened."

"The water was moving," I insisted. "There was something in it. One of the guards even fired a line-launcher."

"Do you want to be transferred?" Neil interrupted, his voice scarcely audible. "Because this is how you get transferred. Or worse."

The table became silent.

Their faces told me what I needed to know. They had seen similar things before, events that were instantly denied and buried.

After breakfast, Strickland stopped me in the corridor.

"Mercer, a word."

He led me into a small meeting room and shut the door.

"I'm reassigning you to the western production deck, effective immediately."

The western deck was as far from the incident site as he could place me.

"Why?" I asked, already knowing the answer.

"We require your expertise there. Report to Supervisor Fraser at 14:00. He will brief you on your duties."

"What about what I saw last night? We both know it wasn't a seizure."

Strickland's expression hardened.

"What you believe you saw was distorted by darkness, distance and the stress of an emergency. The medical team has confirmed an epileptic event."

"And the guards? The containment launcher? The thing in the water?"

"There were no guards present when Talbot fell. No weapon was discharged. You are misremembering events because of stress."

He leaned closer.

"This is your first and final warning, Mercer. The official report states that Owen Talbot suffered a seizure and fell overboard. The surviving witnesses have confirmed that account. Any alternative narrative will be treated as a breach of your non-disclosure agreement, resulting in immediate termination and possible legal action."

I understood what had happened to those witnesses. They had been intimidated into repeating the official version, or they would soon be removed.

The threat hung between us.

"Do I make myself clear?" Strickland asked.

"Perfectly."

"Good. Western production, 14:00."

He opened the door.

"Enjoy your breakfast."

I returned to the cabin to shower and change. Before reporting to the western deck, I took a detour past the research medical unit and claimed to have a headache. Through the narrow window in its door, I saw Owen lying on a bed. His eyes were open but utterly vacant, fixed on the ceiling. His body did not move except for the slow rise and fall of his chest.

A medical team in protective equipment surrounded him, taking samples and measurements. One of them noticed me and came quickly to the door.

"This area is restricted," she said, blocking my view. "Do you require medical assistance?"

"A headache. I can come back later."

"The first-aid centre is on the accommodation deck. This unit is for research medicine only."

She waited until I turned and walked away.

Research medicine, not ordinary medical care.

Whatever had happened to Owen, they were not treating him. They were studying him.

At 14:00, I reported to the western production deck as ordered. Supervisor Fraser briefed me on monitoring duties identical to those I had performed in the east. The displays showed another impossibly deep bore section and the same suspiciously stable pressure readings.

Once settled at my new station, I looked across the water surrounding the western platform. From there, I could see almost the entire installation. In the distance, a helicopter descended towards the helideck.

Medical personnel wheeled a stretcher towards it, carrying a motionless figure strapped beneath a sheet. Owen was supposedly being transferred to Aberdeen Royal Infirmary, but the helicopter did not depart in the direction of Shetland or the mainland route to Aberdeen. It turned out to sea, towards the horizon where the survey vessel had disappeared.

In the three days following Owen's incident, the installation changed.

Nothing seemed different at first. The same equipment thundered. The same harsh LED strips shone overhead. The same trace of industrial coffee lingered in the rest areas.

But beneath the routine, something had shifted.

I first noticed it when another helicopter arrived early on the second morning after the incident. Four men stepped onto the helideck, moving like the military personnel I had encountered during specialist security training on earlier contracts. Unlike the regular guards, who at least acknowledged passing workers, these men surveyed everyone with cold calculation.

They wore sidearms openly and communicated through discreet earpieces rather than standard radios. They looked like a government-contracted containment unit, not offshore security.

By the third day, the eastern crew had been stripped bare. At least eight workers I had regularly seen in the canteen had vanished, including everyone who had been on duty with Owen that night.

"Where's Luis Ortega?" I asked Martin when we passed in a corridor.

Ortega had worked the console beside Owen.

Martin's gaze flicked towards a nearby camera before he replied.

"Emergency transfer. Family matter."

"And Peter Ashdown? Mateo Silva?"

They were two more eastern-deck workers I had not seen since the incident.

"The same. Transfers happen."

He quickened his pace, clearly determined to end the conversation.

When my western shift finished, I made a decision. The ache building behind my eyes offered a convincing excuse.

I went to the medical unit near sea level, scanned my access card at the door and pressed the intercom.

"Medical. State your purpose," a woman answered.

"Edward Mercer. I've a headache that won't ease."

The lock buzzed.

The front room resembled an ordinary offshore clinic, with examination couches, supply cabinets and a desk where a nurse in scrubs looked up at me.

"What seems to be the trouble?"

"The headache started this morning. It's getting worse."

She indicated an examination couch.

"Sit down. I'll get you something for it."

As she turned towards a medicine cabinet, I examined the room. A second door at the rear of the unit stood partly open. Through the gap, I could see what appeared to be a hospital bed fitted with restraints.

"Would you mind if I used the toilet first?" I asked casually.

"Through there."

Without turning, she pointed to a door on the right.

I waited until she was occupied with the cabinet, then crossed quickly to the partly open door. Three brisk steps carried me through.

The room beyond bore no resemblance to the clinic. Harsh white light fell across equipment I did not recognise, monitors filled with unfamiliar readouts and machines emitting a low electrical hum.

At the centre of it all, Owen lay strapped to a bed.

His eyes remained open, staring at the ceiling without blinking. They were wrong. His pupils had dilated until his eyes appeared almost entirely black. His skin had acquired a waxen sheen, and dark lines traced the veins beneath it.

A woman in a white laboratory coat stood beside the bed, drawing blood from Owen's arm whilst entering notes on a tablet. She was so intent on her work that she did not notice me until she looked up. Her eyes widened.

"This area is restricted."

She moved to block my view.

"You need to leave at once."

The nurse appeared behind me.

"Sir, the toilet is the other door. This area requires separate clearance."

"Sorry. Wrong door," I said, trying to look suitably confused whilst taking one final look at Owen.

His body seemed wrong in a way I could not define, too still, as though he were not breathing by any natural process.

The nurse closed a firm hand around my arm.

"This way, please."

Back in the examination room, she gave me two white tablets and a cup of water.

"Take these now. I can provide more for later if necessary."

I swallowed them whilst watching the researcher in the adjoining room press what looked like an alarm control on her desk.

"You should return to your quarters and rest," the nurse said, already guiding me towards the exit.

I moved quickly along the corridor towards the accommodation deck, trying to understand what I had seen. Owen was not being treated. He was a research subject.

And whatever was wrong with him went far beyond the effects of nearly drowning.

That evening, I waited for Callum to return to the cabin. When he finally came in, I wasted no time.

"We need to talk about Owen."

Callum stopped and looked around before replying.

"I don't know what you mean."

"I saw him today. He's still aboard, strapped to a bed like a laboratory animal."

Callum crossed to the sink and turned the tap on full. He beckoned me closer.

"Not here," he whispered beneath the rush of water. "They listen."

"Who listens?"

"Everyone."

His gaze moved towards the ceiling.

"Owen isn't the first. There have been three others in the past year."

"Three others pulled into the sea?"

I kept my voice low. He nodded.

"The company calls them accidents or medical emergencies, but they were taken in the same way as Owen."

"By what?"

"I don't know."

The fear in his eyes appeared genuine.

"No one knows, or no one who talks about it remains here for long."

"What happened to the others afterwards?"

"They never returned to the installation."

Callum abruptly shut off the water.

"That's all I'm saying. We should go to dinner."

The canteen felt different that evening. Conversations sounded forced, full of long pauses and carefully chosen words. The newly arrived security personnel occupied a table of their own and watched everyone else.

No one mentioned Owen or the other missing workers.

That night, I lay awake listening to the strange pulse below the installation. It seemed stronger than before, more insistent. Callum fell asleep quickly, his breathing slow and even.

I stared at the ceiling and thought about Owen's black eyes, the dark lines beneath his skin and the researcher drawing his blood.

Morning came after another restless night. I sat up and reached for my work boots beside the bed. When I picked up the left one, a small piece of tightly folded paper fell to the floor.

I glanced at Callum, who still appeared to be asleep, before unfolding it. The handwriting was cramped but legible.

B3. When the night alarm sounds. Come alone.

I folded the note again and slipped it into my pocket. Who had left it, and how had they entered our quarters without either of us noticing?

My shift that day was on the western production deck, monitoring underwater cameras and drilling data. Around midday, movement on one of the camera feeds caught my attention. The image showed the seabed near the main support columns, dimly illuminated by the installation's exterior lights.

Something moved across the screen.

Not randomly, as if carried by the current, but with purpose. I followed it across three camera angles as it circled one of the support columns. Whatever it was, it remained difficult to make out: darker than the surrounding water, with what looked like several arms or tentacles.

Neil Bancroft walked past my station and stopped when he saw what had caught my attention.

"What's that?" I asked, pointing at the shape.

His face revealed nothing.

"Where?"

"Right there."

I pointed as the thing moved into view on another camera.

"That movement isn't like any marine life I've ever seen."

Without a word, Neil reached across and tapped several keys. The screen changed to another view in which everything appeared normal.

"System diagnostic," he said loudly, taking out his radio. "Control, this is Bancroft. Running a diagnostic sweep on western deck cameras seven through twelve. Temporary feed interruption."

"Copy that," came the reply. "Authorised."

He turned to me with a flat expression.

"The underwater feeds pick up interference sometimes. Nothing to worry about."

"That wasn't interference," I said. "Something was moving down there."

"Just tricks of the light in the water. Happens all the time."

He walked away, but stationed himself at a nearby console from which he could watch everything I did. I tried to restore the original feed, only to discover that my access had been restricted.

For the rest of my shift, I went through the motions of checking gauges and entering figures, my thoughts fixed on the note in my pocket.

B3. When the night alarm sounds. Come alone.

I had never seen B3 on any installation map. It had to lie within a restricted section, probably behind clearance far above mine.

I would have to find it without being caught by security, who were watching everything more closely now. By the end of my shift, I had considered every risk. Whatever was happening on this installation went beyond unusual drilling operations or workplace accidents. People were being taken by something in the water, and instead of stopping it, Caledonian Deep Energy was studying it.

The message linked B3 to an alarm, but offered no time. I returned to my quarters intending to remain awake and follow it whenever the signal came. The truth was worth the risk. I had to face the facts: aboard this installation, knowing what was really happening might save my life.

It might mean the difference between staying alive and becoming the next person strapped to a bed with dark, empty eyes.

I must have fallen asleep whilst waiting, because an explosion woke me with a violent jolt. The clock beside my bunk read 02:37. An alarm shrieked for six seconds, then cut off, leaving an unnatural silence behind it.

Callum was not in his bunk.

I pulled on my trousers and shoved my feet into my boots without tying them. The door hissed open as I stepped into the corridor. Red emergency lights had come on, throwing hard shadows across the walls. The corridor was deserted.

There were no security personnel rushing to investigate and no workers emerging from their quarters. Only silence, where there should have been chaos.

I headed towards the source of the explosion, following the smell of smoke and something else - something metallic and wet.

When I turned the corner towards the B-section stairs, I saw him.

Peter Ashdown, the quiet instrumentation technician I had noticed at meals and met briefly during an earlier handover, sat against the wall with one hand clamped to his neck. His name strip was still visible on his coveralls. Blood seeped between his fingers, ran down his arm and gathered on the floor.

His eyes widened when he saw me.

"Mercer," he gasped, his voice barely audible. "Help me up."

I rushed to his side and examined the wound. A containment bolt had torn into his neck just above the collarbone. It had missed the major vessels, but blood was flowing steadily and the wound was severe.

"We need to get you to the first-aid centre," I said, reaching for my radio before remembering that I had left it in my quarters.

Peter seized my arm. He was frighteningly strong for someone losing so much blood. Desperation filled his face.

"No," he whispered. "They did this. Listen to me."

I leant closer as his voice weakened.

"They're not drilling for hydrocarbons," Peter said, every word costing him visible effort. "They're drilling into it. The boundary. It's coming through."

Blood bubbled at the corner of his mouth.

I tried to press my hand against the wound, but he pushed it away.

"We're test animals," he continued, his breathing becoming laboured. "Get away from..."

His body suddenly stiffened. A violent convulsion shook him from head to foot. His grip tightened painfully around my arm, then released as he slumped against the wall. His eyes remained open, fixed on the ceiling. His breathing was so shallow that, in the red light and my panic, I could not tell whether it had stopped.

Footsteps rang from the corridor to my right: heavy, purposeful steps, several people moving quickly.

I looked around frantically. The stairwell door was too far away. They would see me before I reached it.

About 3 metres away stood a narrow door marked STORES. I moved as quietly as I could, opened it and slipped inside just as the footsteps rounded the corner.

The cupboard was cramped and dark, packed with cleaning materials and maintenance equipment. Through a narrow gap where the door failed to close properly, I could see Peter and the widening pool of blood around him.

Graham Strickland came into view, flanked by two members of the specialist armed security unit. Both carried carbines at the ready. They approached Peter cautiously. One checked for a pulse, then looked up.

"Alive. Weak and unstable."

Strickland took out his radio.

"Subject P compromised," he said in a calm, matter-of-fact voice. "Containment breach possible. Prepare Unit Seven."

Subject P, not Peter. Subject P.

One guard photographed the scene whilst the other opened a case and removed a syringe. They turned Peter's head aside, exposing the wound. The guard injected the contents directly into the flesh around it.

"Tracker and suppressant administered," he said.

"Full clean-up protocol," Strickland ordered. "I want this corridor sterile before the morning briefing."

The guards nodded, then lifted Peter between them. His arms hung limp and his head lolled backwards, but I saw his chest rise once before they carried him away. Strickland followed, speaking quietly into his radio. I could not make out the words.

I waited until the footsteps had faded completely before easing open the door. The corridor was deserted again, with only the pool of blood proving that Peter had ever been there.

Senior engineers were permitted to keep one company-issued mobile in offline mode, despite the platform's general restrictions. I took mine from my pocket and photographed the blood pattern and its position beside the B-section stairwell.

Then I returned to my quarters with questions churning through my mind. What boundary had Peter meant? What did a containment breach involve? Why had Strickland called him Subject P instead of using his name? And where had Callum gone?

I spent the rest of the night awake, staring at the ceiling and listening for anything unusual. Callum never returned.

Morning arrived without further incident. I showered in the en-suite and dressed almost without thought, Peter's warning still lodged in my mind.

As soon as I entered the corridor on my way to breakfast, I noticed that the blood had gone. It had not merely been cleaned. Every trace had vanished. The floor gleamed as though freshly polished, without even the smell of cleaning fluid.

The canteen was filled with ordinary morning activity. Workers ate breakfast and discussed the rota as if nothing had happened. I saw Martin Hargreaves and Neil at their usual table and joined them, searching the room for any sign of Callum.

"Either of you seen Callum this morning?" I asked casually.

Martin shook his head.

"Not since yesterday's shift."

Neil did not look up from his coffee.

The daily briefing began at precisely 07:30, with Strickland standing at the front of the room, as composed as ever. He covered routine updates, production figures, maintenance schedules and safety reminders without once mentioning an explosion, an alarm or an injured man.

When he invited questions, I raised my hand. The room became quieter than usual.

"Has anyone seen Peter Ashdown today?" I asked, watching Strickland's face. "He wasn't at breakfast."

His expression did not alter, but something hardened in his eyes.

"There is no member of personnel by that name aboard this installation," he replied evenly. "Perhaps you were dreaming."

Several workers shifted uneasily. Martin stared down at the table. Neil became intensely interested in a loose thread on his sleeve.

"I saw him last night," I said. "Near the B-section stairwell."

Strickland regarded me coldly.

"Mr Mercer, I am concerned about your state of mind. Prolonged offshore isolation can cause stress-related hallucinations in some people. Perhaps you should attend the first-aid centre for an assessment."

He turned away and moved to the next question as though I had said nothing of consequence. But I saw him survey the room, noting everyone who appeared unsettled by the exchange.

After the briefing, I went to my assigned station on the western deck. At the security checkpoint, three unfamiliar guards watched me with open suspicion.

Throughout my shift, I could not dislodge Peter's words.

They're not drilling for hydrocarbons. They're drilling into it. The boundary.

Every pressure reading I logged and every gauge I monitored acquired a new significance. What exactly was I helping them penetrate? My thoughts kept returning to Peter bleeding against the wall, Strickland's cold denial, Subject P and Unit Seven.

I knew one thing with absolute certainty. Something was happening aboard the installation that went far beyond energy exploration. It was something worth killing for, or at least making people disappear for. As the figures on my monitors climbed and the instruments probed deeper into whatever lay beneath us, I wondered how many others had uncovered the truth before me.

And what had happened to them afterwards.

A week passed after Peter's disappearance without any official acknowledgement that the incident had taken place. The blood beside the B-section stairwell had been removed so completely that it might never have existed.

There was no memorial, no minute's silence, not even a passing reference in the daily briefings. Peter Ashdown had been erased.

The new rota was issued on Monday morning, and I saw that I had been moved to the southern deck. When I looked up from the tablet, Strickland was watching me from across the canteen, his face unreadable.

"Southern deck?" I asked when Martin sat down with his breakfast. "What's down there?"

Martin chewed his eggs slowly, buying himself time.

"Newer equipment. Different monitoring parameters."

"Is that where they took the sensor frames I saw arriving last week?"

The compact survey vessel had approached from the south-east and unloaded a series of sealed frames onto the southern deck.

Martin glanced towards the nearest security camera.

"Follow the procedures and you'll be fine."

That was all anyone would tell me. Even Neil, who usually offered at least a bare minimum of information, developed urgent duties elsewhere whenever I approached.

Callum had not returned to our quarters since the night Peter disappeared. His bunk remained untouched, his few personal possessions still in place. He had simply vanished.

When my shift began that evening, a security escort took me to the southern deck for the orientation Strickland had ordered. We passed through three checkpoints, each requiring higher clearance than the last.

"Your temporary access card," the guard said, handing it to me. "Valid only during assigned shifts. Surrender it immediately after your twelve hours."

The southern deck was not simply another drilling section. It housed an entirely different operation.

The chamber covered roughly the area of two five-a-side football pitches. At its centre stood a vast circular machine that descended through the deck. It bore little resemblance to conventional drilling equipment. Transparent tubes crowded its frame, filled with cold green-white liquid that pulsed in time with the strange vibration I had sensed since my arrival.

The guard pointed to a monitoring station on a raised platform overlooking the main deck.

"Track the pressure readings and log any irregularities. Do not leave that station under any circumstances. Emergency procedures are in the manual."

Then he left.

The heavy door hissed shut behind him, leaving me alone with the hum of machinery and the measured pulse of green-white liquid.

Six screens occupied the monitoring station. The central display showed a depth of 13,620 metres, far beyond the figure I had seen on the eastern deck. A note in the technical header identified it as a separate southern bore instrument, monitoring a deeper exploratory section rather than the main eastern drill string.

Another screen displayed what appeared to be geological strata, but the lowest formations resembled no rock structure I had ever encountered.

Hours passed without incident as I recorded readings and watched the counter advance slowly. Nobody visited or called. Elsewhere on the installation, workers crossed paths even during quiet shifts. Here, I felt entirely alone, surrounded by machinery and the steady rhythm rising from below.

At 02:17, the lights flickered. They dimmed for a moment, then recovered.

I checked the electrical readings. Every system reported normal operation. Strange, but not yet alarming.

Ten minutes later, it happened again.

This time, static crawled across the screens. The depth display jumped to 15,410 metres for a fraction of a second before returning to 13,622.

I reached for the radio to report the fault, then noticed something at the door.

Water was seeping beneath the sealed entrance. A thin, oily film spread across the metal floor in a way no liquid should. Instead of following the slight gradient towards the drainage grilles, it moved against it and gathered itself into a widening pool.

It made no sense. The deck stood about 12 metres above sea level, and the entrance had several pressure seals. Yet the pool continued to grow.

I backed away.

The water rose in a narrow column for about 1.2 metres, then stretched higher, swelling into a human-sized figure. The lights flickered once more. In the momentary gloom, the column shaped itself into a torso, arms and a head.

When the lights returned, the water sloughed away and revealed what it had carried.

The thing had Peter's face. The features were unmistakable, but they belonged to a body that was no longer human. Its limbs had lengthened into thin, distorted shapes, their joints bending in impossible directions. Its skin was almost transparent, revealing veins illuminated by the same cold green-white glow as the liquid within the machine.

I stumbled against the monitoring platform's railing.

The creature stared at me with eyes like black hollows, reflecting no light. Its mouth opened to reveal concentric rows of needle-like teeth. But instead of attacking, it raised one webbed hand towards me.

"Help."

The sound was scarcely recognisable as speech, a wet attempt at language forced through a throat no longer made for human words.

"Edward."

It knew my name. The thing wearing Peter's face knew who I was.

"Peter?" I whispered.

Its head twitched in what might have been a nod.

"Not much time."

Every word appeared to hurt it.

"They're letting it in."

I reached towards the emergency control behind me. The creature saw the movement and crossed the deck with terrifying speed. Its webbed hand shot out, fingers far too long and bent at unnatural angles.

"Listen," it gargled, green-white fluid spilling from its mouth. "Boundary breaking. They want..."

I slammed my palm onto the emergency control.

Alarms erupted throughout the southern deck. The creature recoiled and clutched at what remained of its ears, its mouth stretched into a silent scream.

Within seconds, the door burst open. Four specialist security officers in sealed protective gear rushed inside. Two carried carbines. The others bore pneumatic line-launchers modified to fire barbed containment bolts, with wide emitters producing the same green-white energy visible in the creature's veins.

"Containment breach. Target acquired," one shouted into his radio.

They aimed at the creature. It turned towards me one last time, and despite everything monstrous in its altered face, something human remained in its expression.

"Find others," it gargled.

The security team fired. Barbed bolts struck its torso and limbs, followed by concentrated green-white containment pulses from the launchers' emitters.

The creature collapsed, convulsing violently. The light in its veins flashed and faltered like a failing lamp.

Two more personnel entered with a transparent containment capsule like a glass coffin. They forced the shaking figure inside and sealed the lid. Cold green-white fluid flooded the chamber. The convulsions continued for several seconds, then stopped.

Strickland appeared in the doorway, composed despite the chaos around him. He surveyed the scene, spoke briefly into his radio and approached me. I remained pressed against the railing, unable to reconcile what I had seen.

"That was Peter," I said. "He knew my name. He was trying to warn me about the boundary."

Strickland's face remained blank. He took a small case from his pocket and removed a syringe filled with clear liquid.

"Standard protocol requires a mandatory sedative following possible contamination exposure," he said in a clinical, detached tone.

"That thing had Peter's face," I insisted. "He knew me. He was trying to communicate. What the hell is happening here? What are you people really drilling for?"

Strickland nodded to someone behind me. Strong hands closed around my shoulders and held me in place. I struggled, but the grip only tightened.

"This will help you process the trauma," Strickland said, advancing with the syringe. "When you wake, we will have a serious discussion about your future aboard this installation."

The needle entered my neck, and cold spread through my body. The room blurred. Before darkness took me, I saw them wheeling away the capsule. Peter's altered face rested against the transparent wall, his black eyes fixed upon me.

I woke beneath harsh LED strip lighting. The ceiling panels were off-white, with small water stains in one corner. A dull ache filled my skull, making even the act of blinking painful. An intravenous line ran from my arm to a bag of clear fluid beside the bed.

"Welcome back, Mr Mercer."

Strickland sat beside me, holding a tablet. His face remained impassive, but his eyes followed every movement I made.

"How long?" I asked, my voice rough from disuse.

"Twelve hours, give or take." He tapped the tablet. "You have been under observation since the incident on the southern deck."

I tried to sit up, but my muscles felt weak and unresponsive.

"Peter Ashdown was not present during your episode," Strickland said smoothly. "You experienced what our medical team describes as a stress-induced hallucination. It is not uncommon in this environment, particularly amongst those unaccustomed to prolonged isolation."

"That wasn't a hallucination." I forced myself upright. "Peter was there. He knew my name. He was trying to warn me that the boundary was breaking."

Strickland's expression shifted. His eyes narrowed slightly. He set down the tablet and leant towards me.

"I see."

He paused, studying me.

"In that case, there are certain matters you need to understand."

A doctor entered, checked my vital signs and removed the intravenous line. She left clean coveralls for me and departed without speaking. Strickland waited beside the door whilst I dressed, his back turned but his posture alert.

"Follow me," he said when I had finished.

We left the medical suite and proceeded through corridors I had never seen. Security was heavier here. Cameras tracked our progress, and guards stood at key junctions wearing tactical equipment and carrying carbines more specialised than the weapons elsewhere. Every door required Strickland's access card and a fingerprint scan.

We entered a lift that demanded both his card and a code entered on a keypad. The display showed our destination as B4.

"B4 isn't on any installation map," I said.

Strickland did not answer.

The lift opened onto a pristine white corridor that resembled a research facility rather than any offshore energy installation. Strickland led me into a conference room containing a long table and several chairs. A large wall-mounted display showed the Caledonian Deep Energy logo.

"Wait here," he said, and left.

I sat alone for nearly ten minutes, examining the room. Everything was costly and advanced, far beyond what any ordinary energy operation would install in a supposedly temporary facility. The tabletop doubled as a touchscreen. Acoustic panels lined the walls, preventing anyone outside from overhearing. Small cameras occupied each corner of the ceiling.

The door opened and a woman entered. She appeared to be in her early fifties, with short dark hair, and wore a business suit that looked deeply out of place offshore. Her handshake was brief and firm.

"Edward Mercer," she said, taking the seat opposite mine. "I am Dr Eleanor Vane, director of Project VEIL. I understand you have had an enlightening experience."

Strickland entered behind her and took up position beside the door.

Dr Vane touched the table. The wall display changed to a digital cross-section of the installation and the seabed beneath it.

"I will be direct, Mr Mercer. Caledonian Deep Energy is not principally an offshore energy company. What we are doing here extends far beyond resource extraction."

She enlarged a region deep beneath the seabed.

"The anomaly was first detected twenty-eight years ago during a geological survey. Exploratory work continued covertly for thirteen years. Fifteen years ago, this installation was commissioned to study it at scale."

The display showed sonar scans, energy signatures and streams of data I could not interpret.

"What we found," she continued, "was a localised weakness in the boundary between physical realities. At this location, the division between our reality and another has become dangerously permeable."

I stared at the screen, trying to absorb her words.

"You're not drilling for hydrocarbons. You're drilling into another reality."

"We are studying the boundary," she corrected. "Taking samples, monitoring fluctuations and learning what exists beyond it, as well as how it interacts with our world."

"And the people who disappear? Owen Talbot? Peter?"

Dr Vane's expression remained cool and professional.

"Exposure incidents. The boundary leaks, Mr Mercer. Or, to put it another way, material from the other side sometimes crosses into ours. People who come into contact with it begin to change. Their bodies acquire properties belonging to the adjacent reality."

She touched the screen again, and a video appeared. I recognised the containment chamber I had glimpsed whilst searching for Owen.

Dozens of transparent tanks lined its walls, each holding a floating human figure. Some remained almost entirely human. Others had become something else.

"These are our current research subjects," Dr Vane said. "Former personnel who have begun the conversion process. We study them to understand the nature of the change, and to determine whether it can be controlled or reversed."

One tank contained Owen. His eyes were open and aware, even though his body had already begun to alter. The helicopter supposedly taking him to Aberdeen Royal Infirmary had flown out to sea instead. Now I understood that it must have carried him to a research vessel or auxiliary containment platform before he was returned here.

Another tank held the creature I was certain had once been Peter.

"Peter didn't die in the corridor," I said as the pieces aligned in my mind.

"Correct," Dr Vane replied. "Peter was an early-stage conversion subject who escaped during transfer. Security used a non-lethal containment bolt in an attempt to recapture him. The injection you witnessed contained a tracker and a transformation suppressant. What you encountered on the southern deck was Peter after the next phase of conversion."

Her casual tone disturbed me almost as much as the images. She spoke as if describing test specimens rather than men with whom I had worked.

"You're experimenting on them," I said, unable to conceal my disgust.

"We are learning from them," she corrected. "The potential applications of this discovery are beyond calculation, Mr Mercer. Non-standard materials with properties that contradict our physics. Medical techniques capable of transforming the treatment of currently incurable conditions. Defence applications involving adaptive personnel, hostile biological conversion and materials against which conventional weapons would be ineffective."

She leant forwards, intensity entering her eyes.

"That brings me to the purpose of this conversation. You now understand the true nature of our operation. That leaves us with limited choices."

Strickland shifted slightly beside the door, reminding me that he was there.

"The first option," Dr Vane continued, "is that you join the research team, with increased clearance and compensation. Your engineering experience would be valuable, and you have already shown remarkable adaptability."

"And the second?" I asked, though I could guess.

"Memory modification and transfer. You would be reassigned to one of the Calder rigs, with no recollection of the past two weeks."

Her expression made her preference clear.

"You have potential, Edward. I would rather not waste it."

My thoughts raced. Both choices were dangerous. If I refused to join, I doubted they would simply erase my memory and send me away. More likely, I would end up inside one of those tanks. But agreeing too quickly would invite suspicion.

"This is a great deal to take in," I said carefully. "I need time to consider it."

Dr Vane studied me, then nodded.

"You have until tomorrow morning. In the meantime, I am granting you B3 observation-only access, including the legacy archive, but excluding all laboratories. You may also enter B2 communications and review selected internal research material. It may help you reach an informed decision."

She stood.

"One further point, Mr Mercer. Any attempt to tell the outside world what you have learnt will be detected and dealt with, for everyone's safety."

Strickland escorted me back to my quarters, which felt absurdly ordinary after everything I had seen. The bunks, desk and window seemed to belong to a different reality, one in which offshore installations were simply offshore installations and people did not become monsters.

Callum's bunk was still empty and untouched.

I lay on my own for hours, considering everything: the drilling, the disappearances and the armed security. It all made a hideous kind of sense. CDE had found a weakness between realities and was tampering with it, regardless of what might cross through or who might be changed by exposure.

I had been close to Peter's blood. I had stood only metres from the manifestation on the southern deck. I pushed those thoughts aside.

I needed to get word out. I needed documents, images and evidence substantial enough to expose what was happening here.

At 01:47, I left my quarters. The B2 communications access Dr Vane had granted might offer my only opportunity. The corridors were mostly empty, with skeleton crews covering the night shift. I nodded to the few workers I passed and tried to appear untroubled as I made my way towards the communications centre.

My temporary clearance opened the door.

Banks of equipment hummed inside: satellite arrays, radio systems, computer terminals and all the technology required to maintain contact with the outside world from an installation east of Shetland.

I sat at a terminal and began composing an emergency message for simultaneous transmission to HM Coastguard, mainland police and several news organisations.

When I attempted to connect to an external network, a warning appeared:

ALL OUTGOING COMMUNICATIONS ARE ROUTED THROUGH CDE SECURE SERVERS FOR SECURITY VERIFICATION. PLEASE AWAIT TRANSMISSION APPROVAL.

Of course. They would never leave an unrestricted channel through which someone could expose them.

I needed another plan.

Instead, I entered the internal network. My engineering credentials opened most standard systems, and Dr Vane's temporary access exposed a selection of research files. I searched for material I could preserve as evidence.

There was more than I expected: video logs of early encounters with boundary material, medical records from conversion cases and papers proposing practical uses for technologies derived from the anomaly.

I connected my company mobile to the terminal with its authorised maintenance cable. Senior engineers used the same connection to transfer offline diagnostic logs, so the hardware accepted it without protest. I began downloading everything available, watching the progress indicator advance with agonising slowness.

A sound in the corridor made me freeze.

I disconnected the mobile, slipped it into my pocket and closed the research files. By the time the door opened, the terminal displayed routine equipment logs of the sort a senior engineer might reasonably inspect.

A security guard looked inside. His eyes narrowed when he saw me.

"Working late, Mr Mercer?"

I nodded, forcing myself to appear calm.

"Familiarising myself with the systems. Dr Vane upgraded my clearance."

He checked his tablet, then gave a reluctant nod.

"The night supervisor must be informed whenever personnel enter communications outside normal hours."

"Sorry. First time down here. I'll remember."

He subjected me to one final suspicious look before leaving.

I waited five minutes, then departed the communications centre. The mobile felt heavy in my pocket, loaded with material that might expose the entire operation if I could leave the installation alive.

The walk back seemed longer than before. Every corner felt like a place where security might be waiting. I chose a slightly different route, hoping to make my movements less predictable.

As I entered the final corridor, I saw someone standing in the shadows near my door.

I slowed, considering whether to turn back. Then the figure stepped into the light.

Callum Price stood there, his face blank. His gaze dropped to the mobile protruding slightly from my pocket, then returned to my eyes. He said nothing, but the message was unmistakable.

He knew what I had done.

We faced each other in silence.

"We should talk inside," he said at last, scarcely above a whisper.

I hesitated. If Callum truly worked for security, entering our isolated quarters with incriminating evidence in my pocket could be walking willingly into a trap. Remaining in the monitored corridor was no safer.

I nodded and followed him through the door.

Once inside, Callum checked the corners of the room, then went into the en-suite and turned on the shower at full pressure. Water hammered against the tray and filled the cramped quarters with noise.

"They have microphones everywhere," he said quietly. "But the plumbing masks us."

I kept my distance, my back against the wall.

"Are you going to report me?"

Callum shook his head.

"Not yet. What did you find in communications?"

I weighed my options. He had vanished on the night of Peter's escape and returned just as I gathered evidence. But I needed information, and perhaps an ally.

"Research files. Videos. Medical records of the conversions."

I did not mention that the files were now on my mobile.

"They're not drilling for hydrocarbons. They're studying something crossing from another reality."

"I know."

Callum sat on his bunk, suddenly looking exhausted.

"I've known for three months. I spent two years on other CDE installations before my transfer here."

"Where have you been since Peter disappeared?"

"Detained and questioned. They thought I helped him escape. They released me today and put me back on monitoring duty, which is how I knew where you'd been tonight."

"How much do you know about what they're doing to those people?"

"Enough." He rubbed his face. "The research subjects, the tanks, the conversion process."

I thought about the supply schedule I had memorised during orientation.

"Kestrel Three comes in two days. Supply service from Aberdeen."

Callum looked up sharply.

"Don't even consider it. Strickland's people watch every transfer. Anyone trying to board without authorisation would be stopped at once."

"I have upgraded clearance," I reminded him. "From Dr Vane."

"Observation access to B3 and standard access to B2. The helideck requires B1 or above."

I paced the cramped room, thinking.

"I need to see more. I need to understand what is really happening here."

"You should accept their offer," Callum said, his voice hollow. "Join the research team. It may be the only way you survive."

"The way the others survived? The way Peter survived?"

I leant closer, keeping my voice beneath the sound of the shower.

"I'm leaving this installation, and I'm taking proof of what they're doing."

Callum stared at me for a long moment, then nodded once.

"Get some sleep. We'll talk tomorrow."

I lay awake for hours, planning my next moves. I needed to access the lower decks, gather stronger evidence than the files already stored on my mobile and find a way aboard Kestrel Three. Possibilities and dangers chased one another through my head until exhaustion finally dragged me under.

Morning arrived too soon.

Strickland conducted the daily briefing and watched me with particular care. Dr Vane was absent, but it felt deliberate rather than accidental. Callum remained on the far side of the canteen and avoided looking at me.

Afterwards, I tested my new clearance by taking the lift to B3. The system accepted my temporary observation credential and carried me deeper into the installation than I had previously travelled.

The doors opened onto a pristine white corridor lined with security doors. Most rejected my card, but one marked OBSERVATION admitted me, exactly as Dr Vane had promised.

The small room beyond had a broad viewing window overlooking an enormous laboratory. At least two dozen transparent containment tanks lined the walls below. Each was filled with pale green-white liquid, and each held a person - or something that had once been a person.

Some appeared almost normal, their changes still subtle: dark veins beneath pale skin, fingers fractionally too long and eyes beginning to deepen into black, lightless hollows.

Others had advanced much further. Their bodies were twisted and remade, like Peter's on the southern deck.

A control panel beneath the window allowed me to magnify individual tanks. I selected one in the corner, and my stomach tightened.

Owen floated inside, his conversion far worse than when I had seen him in the medical suite. His limbs had lengthened, their joints bending at unnatural angles. His skin had become almost transparent, exposing dark, pulsing veins. Yet his eyes remained aware. They tracked every movement made by the technicians below.

As I watched, a technician approached Owen's tank with a testing device. Owen immediately pressed his hands against the ballistic glass, his mouth moving as if he were pleading. The technician ignored him, took readings from a panel mounted on the tank and moved on.

I shifted the view between other tanks.

Some occupants hung limp, unconscious or perhaps dead. Others moved constantly, pushing at the glass with their mouths open in silent screams. One figure caught my attention. Almost nothing recognisably human remained except its eyes, which stared directly towards the observation window as though it knew I was there.

Standing beside those tanks, even behind the viewing glass, filled me with a cold unease. Their green-white fluid pulsed in time with the vibration under the deck. I wondered whether proximity alone was enough to change a person.

A door at the end of the observation room opened into a small archive included within my temporary clearance. Filing cabinets held legacy originals from the project's earliest years. A notice explained that the documents had never been placed on the network and were retained offline as the authoritative records.

I searched quickly until I found the original mission plans.

The documents began twenty-eight years earlier, long before the present installation was commissioned. CDE's predecessor had detected the localised weakness during a routine geological survey. Initial exploratory drilling produced impossible readings, followed by the first exposure incident, which changed two workers.

Instead of ending the operation, the company concealed the discovery. Covert exploration continued for thirteen years before this specialised installation was built fifteen years ago to expand Project VEIL.

Page after page recorded what they had learnt about the transformative effects of exposure. One document listed potential applications: hostile biological conversion, adaptive personnel capable of surviving conditions beyond ordinary human limits, and industrial use of non-standard materials whose properties contradicted accepted physics.

I photographed as many pages as I could, adding them to the evidence stored on my mobile.

Voices sounded in the corridor outside.

I returned the files to their precise positions and left through a side door, marked as an authorised observation exit, which opened onto the main corridor. Whether Callum had interfered with the monitoring or Dr Vane genuinely wanted me to see the archive, the route remained open long enough for me to leave unnoticed.

I spent the rest of the day at my assigned station on the western deck, performing my duties mechanically whilst thinking about what I had seen. The people in those tanks had once been workers like me. One error, one moment of exposure, and CDE had stripped them of their names and turned them into research specimens instead of patients to be saved.

When my shift ended, I returned to my quarters and found Callum waiting. He had turned on the shower again, and steam drifted through the room to help conceal our conversation.

"You went to B3," he said.

It was not a question.

"How did you know?"

Callum looked at me with a mixture of frustration and resignation.

"Because it's my job to know. I was assigned to monitor you from the moment you arrived."

My hand moved towards my pocket, where my company-issued mobile held the evidence I had gathered.

"Don't," Callum said quickly. "I'm not here to stop you."

"Then why are you here?"

He sat heavily on his bunk.

"My elder brother was on this installation three months ago. A technical specialist, like Neil. He noticed the same things you did - the secrecy, the disappearances. He started asking questions."

I could see where this was going.

"He was exposed."

Callum nodded, visibly distressed but holding himself together.

"They said it was an accident. A containment breach during a routine maintenance check. I'd already spent two years at other installations in the company's network. By the time my transfer here was approved, he was already in one of those tanks."

"Which one?" I asked quietly.

"Tank 17. The one in the far corner." His voice faltered. "He still recognises me when I visit. At least, I think he does."

Everything fell into place. Callum's reluctance to talk, his disappearances and the warning note I had received had all been leading to this moment.

"That's why you slipped me the note about B3," I said. "You wanted me to see the truth."

"I wanted someone else to know what they're doing here." He looked up at me, his expression hardening with resolve. "Kestrel Three arrives tomorrow at 08:00 for the supply transfer. If we're going to get you and that evidence off this installation, we need to create a distraction large enough to keep security too busy to stop you."

"We?"

"I can't leave. They'd know I helped you. But I can make sure you get aboard that helicopter."

Callum took out a small tablet and showed me a schematic of the installation.

"The primary power coupling for the drilling operation is here, on C1. If it fails catastrophically, emergency protocols will pull security away from every non-essential area to contain the situation."

I studied the schematic.

"That's close to the boundary they're drilling into. Wouldn't that be dangerous?"

"It won't damage the containment systems. It'll only create enough chaos for you to reach the helideck." He pointed to another section. "Security will evacuate all non-essential personnel to the upper decks. That's your window."

"What about you?"

Callum smiled bitterly.

"I'll be busy reporting a piece of broken equipment that needs immediate repair. By the time they work out what's happened, you'll be gone."

We spent the next hour planning every detail. Callum knew the security protocols intimately, including how to trigger the alarms without being caught. Since being detained and questioned after Peter's shooting, he had been returned to monitoring duty, which gave him access to my movements and enough of the surveillance network to interfere with the cameras along my route.

He had also identified a return-consignment pallet of technical equipment booked for transport to Aberdeen. He gave me its manifest and arranged for my B3 observation credential to be temporarily elevated so that it would identify me as the engineer escorting the consignment.

I memorised the route to the helideck and the precise timing we would need. When we had finished, Callum fixed me with a hard stare.

"When you get out, make sure everyone knows. Not just about the transformations, but about the people. My brother. Peter Ashdown. All of them."

"I promise," I said. "If there's a way to shut this place down and help them, I'll find it."

We slept in shifts that night, too tense to rest properly. Morning brought the same dreary routine as ever: the daily briefing, shift assignments and the ceaseless throb of machinery. No one looking at us would have guessed what we intended to do.

At 07:35, I positioned myself near the lift to the classified research decks and pretended to check equipment readings. Callum had already disappeared towards the power couplings on C1.

At precisely 07:42, the lights flickered. Three seconds later, alarms blared throughout the installation.

"Emergency in section C1. All security personnel report to containment response stations. Non-essential personnel evacuate to the upper decks immediately."

The automated message repeated over the Tannoy system as red emergency lights flooded the corridors.

I joined a group of workers heading upwards, then slipped away at a junction. My temporarily elevated access credential opened a maintenance hatch, and I climbed a ladder that led directly to the helideck level. As Callum had promised, the security checkpoints stood empty, their guards summoned to deal with the emergency below. The cameras covering my route remained fixed on empty corridors or looped old footage under Callum's interference.

I reached the upper deck just as Kestrel Three landed. Rotor wash tore across the helideck, carrying cold spray on the hard North Sea wind, whilst the ground crew hurried to unload the incoming supplies.

Amid the confusion, I joined the technicians checking the manifests. I carried the paperwork for the return-consignment pallet and walked beside it as the ground crew moved it towards the helicopter. My elevated access credential was enough to get me past the sole remaining guard, who was paying more attention to the alarms than to the cards he was scanning.

The pilot was already preparing to depart, plainly eager to get clear of whatever emergency had triggered the installation-wide alarm. I showed him the manifest and my senior engineering credentials.

"I'm escorting this technical equipment back to Aberdeen for repair," I said.

He gave the paperwork a hurried glance, nodded and waved me aboard.

I climbed into the cabin, my pulse racing, and strapped myself into a seat amongst the secured cases and equipment. Through the window, I saw more security personnel appearing at the far end of the helideck. They were responding to an alert that I had been moving through restricted areas without authorisation.

The pilot received clearance to depart, and Kestrel Three lifted away from the installation.

As we climbed, someone emerged onto the helideck below, moving with strange, spasmodic jerks. Even from that height, I recognised Peter Ashdown's transformed figure standing at the edge of the platform, his face tilted towards our helicopter. Those empty black eyes stared directly at me, as though he knew exactly what he was doing.

The radio crackled.

"Supply helicopter Kestrel Three, this is Caledonian Deep Control. You are ordered to return immediately. Repeat, return to the installation immediately. You are carrying an unauthorised passenger."

The pilot looked back at me, suspicion replacing his earlier urgency.

"What's in those equipment cases you're escorting?"

"Standard replacement parts," I said, struggling to keep my voice steady. "Nothing unusual."

He watched me for another moment before turning back to the controls. Whatever his doubts, offshore aviation rules and the controller's authority left him little room to refuse a security recall.

"Control, this is Kestrel Three. Returning as ordered."

The helicopter banked sharply and headed back towards the installation.

As we descended, a peculiar tingling began in my fingertips and crept slowly through my hands. I looked down and saw dark lines beneath the skin of my wrists, tracing the veins up my arms.

The realisation struck with sickening force. I had been exposed. It might have happened when I knelt close to Peter's blood, during the manifestation on the southern deck, or in the long hours I had spent beside the tanks on B3.

It no longer mattered when. I was already changing.

The evidence on my mobile, even if I managed to get it beyond Caledonian Deep Energy's reach, would cost me my humanity. I would become like the people trapped in the tanks below.

The tingling intensified as we approached the helideck. Armed containment staff stood waiting, carbines raised. Others carried pneumatic line-launchers modified to fire barbed containment bolts, the same weapons they had used against Peter.

At the platform's edge, Peter's transformed body watched us descend through black, unblinking eyes.

As the helicopter touched down, the first agonising cramp seized my fingers. I watched them begin to lengthen and grow.