The darkness hit like a shut door to the face.

  One second, there had been the weak green flicker of the wall-wound and Harold’s trembling beam. The next, everything snapped black. Not dim, and shadowed, but black. It was as thick as oil and twice as suffocating. Ethan froze where he’d hit the ground, palms splayed on slick stone, trying to force breath back into his lungs before the panic did it for him.

  Water sloshed somewhere ahead. Heavy water: the kind that moved only when something massive disturbed it. The monster wasn't gone. It was repositioning.

  A cold ribbon of dread slid up his spine.

  He blinked hard into the void. Nothing. Not even the ghost of a shape. He lifted his hand, fingers spread. He could’ve amputated the damn thing, and he wouldn't have known.

  His HUD struggled to compensate.

  [Ambient Light: < 1%]

  [Visual Input Error | Mapping Offline]

  He swallowed, the sound too loud in his helmet. “CelestOS,” he whispered. “Light. Give me… something.”

  CelestOS: Negative. All optical sensors report zero-lumen environment. Auxiliary projection array was compromised in the previous collapse.

  “Then remap the corridor. Give me a way out.”

  A beat of static.

  CelestOS: Inertial mapping remains nonfunctional. Local geometry continues to defy spatial reconstruction. Current state resembles a scrambled topological manifold.

  “English!”

  CelestOS: I don't know where anything is. Including you.

  His pulse spiked hard enough to hurt. He pressed his forehead to the cold stone and forced a count (one, two, three) just to keep the panic from running the show. The air tasted metallic, sharp with the faint mist still drifting from the breached chamber. The lake’s shoreline was somewhere in front of him, but without light, he had no idea where the drop-off began. The monster could be inches from him or thirty meters. Sound warped too easily in these caverns to trust.

  He held still, straining to listen.

  There: a wet scrape. Like claws dragging over rock. Slow. Deliberate. The kind of movement belonging to something that didn't need to rush because the prey wasn't going anywhere.

  His muscles locked.

  He didn't dare stand, nor did he dare crawl. The wrong sound (hell, the wrong breath) might tell the thing exactly where he wasn't supposed to be.

  “CelestOS,” he breathed, keeping his voice a thread. “Is it moving toward me?”

  CelestOS: Unclear. Echolocation is unavailable. I can't differentiate monster locomotion from environmental noise.

  “Then try harder.”

  The AI hesitated. It never hesitated.

  CelestOS: Ethan, the only available suggestion is to reduce your acoustic signature and remain motionless.

  “You think I'm not doing that?” he hissed.

  CelestOS: Operator heart rate is elevated. Please regulate. Your breathing is—

  “CelestOS, I swear, if you lecture me right now—”

  A deeper rumble rolled under his palms. Not the monster: bigger. The entire floor flexed, a slow rising swell of stone shifting under unseen strain.

  His breath hitched. “What was that?”

  CelestOS: Unknown. But the waveform doesn't match the first creature. Ethan, something else is moving. The substrate is—

  He felt a tickle at CelestOs mentioning waveforms and a lack of echolaction in nearly the same breath, but he let it pass. The ground vibrated harder, a low thrum building like a distant engine winding up.

  Ethan’s fingers curled against the rock. His mouth went dry.

  “CelestOS…” he whispered. “What’s happening?”

  The AI’s voice sharpened, strained.

  CelestOS: I believe the mountain is responding.

  The dark didn't feel empty anymore. It felt aware.

  Ethan pressed one hand to the stone, trying to get his bearings, but every direction felt the same: cold, wet, uneven. His breathing rattled loud in his own ears, and each inhale scraped his throat raw. Behind him, something shifted in the lake with a thick, syrupy slosh.

  The clicking started.

  Soft at first, barely there: a dry, hollow tock-tock-tock that bounced off the cavern walls with eerie precision. Ethan froze. It wasn't footsteps. It wasn't breathing.

  It was testing the chamber.

  Mapping him.

  The monster loosed a slow rumble that vibrated through the stone. Not a threat. A sound almost like amusement, like a cat thumping its tail before pouncing again.

  “CelestOS,” Ethan whispered, voice trembling despite him. “Talk to me.”

  CelestOS: The creature is emitting short-range pressure pulses. The pattern resembles echolocation. You are the target.

  “Yeah,” he said, “I got that part.”

  A wave of warm, damp air blasted across him. The monster had moved fast. Ethan flattened himself against the floor, blinking uselessly into blackness as water dripped from its limbs and pattered around him.

  A limb slammed down inches from his head.

  Stone cracked, and dust billowed.

  Ethan bit down on a reflexive scream as the vibration jolted his jaw.

  Something brushed his boot, a gentle tap too gentle for a creature that size. It was tasting distance, not attacking, but playing.

  He tried to crawl sideways. The creature reacted instantly. A massive limb caught his thigh and shoved, not hard enough to break bone, but enough to spin him like a ragdoll. He hit the wall with a grunt, teeth clacking together. Stars burst behind his eyelids even though he couldn’t see a thing.

  This tale has been pilfered from Royal Road. If found on Amazon, kindly file a report.

  Pain flared through his hip as he dragged himself forward again, but the monster was faster. It hooked something under his ribs (a claw? a tentacle? a joint?) and lifted.

  His breath tore from his lungs as he was hoisted off the ground like he weighed nothing. He dangled in the dark, armor creaking under pressure. The creature held him there, as if curious about the noises he made.

  It then dropped him.

  He hit the stone hard, rolling over jagged debris. His helmet rang with the impact. Before he could catch breath, another limb swept sideways and clipped his shoulder. The world spun again as he tumbled across the floor.

  “F—fuck—” he coughed, palms scrambling for purchase.

  The monster followed the sound, clicking softly, clearly enjoying it.

  CelestOS: Ethan, the creature’s behavior indicates non-lethal engagement.

  “It’s—” He gasped for air. “—playing with me. It doesn't matter how quiet I was. I've been fucked from the start.”

  CelestOS: Affirmative.

  Another rush of air. Ethan ducked instinctively, and a massive limb sliced through where his head had been, pulverizing stone. Shards sprayed across his back and legs.

  It didn't want him dead, not yet.

  He crawled backward blindly, boots scraping rock. The creature inhaled (a long, rattling pull) reading him again, mapping him by the sound of his panic, the scrape of armor, and the thud of his heartbeat.

  It was closing in for the kill-moment. He could feel it. The air pressure shifted, heavy and centered, like the creature coiling to strike.

  Ethan forced himself upright, legs trembling. He couldn't outrun it, and he couldn't fight it, but monsters, even clever ones, had blind angles.

  He heard its weight shift, a subtle, grinding repositioning, right above him.

  Now.

  Every instinct in him rebelled, but he didn't hesitate. He dove forward, throwing himself flat against the stone, sliding on dust and damp as a limb hammered down behind him with bone-crushing force. He tucked his knees and rolled under the creature’s bulk, slamming against slick plates and warm muscle, before tumbling out the other side.

  Ethan’s dive bought him seconds (no more).

  He hit the ground hard, rolled through grit, and forced himself onto shaking hands and knees. His pulse throbbed behind his eyes, blurring the thin scraps of bioluminescence that still glimmered faintly along the distant wound in the wall. Everything else remained pitch-black, so dark he couldn't tell where space ended and panic began.

  Behind him, the monster screeched, a wet, serrated sound that rattled the inside of his helmet. Stone cracked as it slammed a limb down, searching for the little animal that had just slipped through its grasp.

  Ethan staggered upright and sprinted into the nearest shadow, boots clattering over debris he couldn't see. His breath tore from him in ragged bursts. All he had was forward.

  But forward wasn't forward.

  The cavern pitched into a tight curve, swallowing his path before he’d taken ten steps. He slapped the wall with an open palm: solid. Not a branch or a fissure, but a dead end disguised as an escape route.

  “CelestOS!” His voice cracked like his throat was splitting. “Give me anything, anything that isn't toward that thing!”

  CelestOS: Acoustic orientation suggests you aren't currently facing the lake. Beyond that, directional certainty is zero percent.

  “Zero? Any chance for at least one?”

  CelestOS: One percent implies accuracy. That would be dishonest.

  He growled, turned blindly, and bolted down a new angle, hoping instinct could outrun geology.

  It couldn't.

  He slammed into a slab of stone he hadn't seen, a wall as smooth as metal, curving inward like a rib. Pain burst up his shoulder. He reeled back, clutching the joint, teeth clenched against a scream.

  The monster answered for him.

  A clawed limb smashed the stone behind him. Dust rained over his helmet, gritty and cold. The creature’s clicking resumed, sharper now and impatient. He could hear the scrape of another limb dragging behind it, tasting the air, triangulating his every breath.

  He backed up until he couldn't. The wall pressed against his spine, cold and unyielding.

  “Oh no,” he whispered. "No, no, no.”

  The monster’s shadow (if you could call the shifting pressure in the dark a shadow) fell over him. He felt it, the massive displacement of air as it loomed. The heat of its breath steamed his faceplate.

  Ethan dropped to a crouch, heart pounding so loud it echoed.

  He needed a plan, a weapon, a miracle.

  He had none.

  But the monster wasn't in a rush. It planted a limb on either side of him: one landing with a crack that sent vibrations up his boots, the other lowering until it grazed the stone a breath from his ear. A deliberate, sadistic cage.

  It lowered itself.

  Ethan’s breath hitched as he realized what it was doing. It was pinning him without touching him, forcing him to wait, to feel the pressure of its presence, and to listen to the deliberate flex of plates above his head.

  Playing with him again.

  “Not—” His voice cracked. “—this time.”

  He dropped flat to his stomach.

  The movement startled the creature. It hissed, a short, violent burst, but too late. Ethan shoved off the stone and slid forward, scraping armor over dust and wet debris, diving under the bulk of its torso.

  Warm, slick muscle brushed his shoulder. Something jointed scraped his boot. He tucked his legs tight and rolled through the narrow gap, ribs straining against the stone as the monster jerked downward, expecting him to rise, not drop.

  He burst out the far side, gasping as fresh space opened before him: a wider arc of cavern lit only by distant glow and blind instinct.

  Ethan didn't know how long he ran (seconds, minutes), but the dark sharpened around him. Every breath burned. His legs buckled in short, stuttering lurches, and he could hear the creature behind him, claws shearing against the stone in a sick rhythm that never quite synced with his footsteps.

  He hit another wall.

  A hard, curved slab of rock met his palms: smooth and impassable. He dragged his hands across it, desperate for an edge, a fissure, anything, but there was nothing. Just cold stone.

  “No, come on.” His voice cracked into a whisper. “Please… not again.”

  The monster slowed.

  He could feel it waiting, assessing, and mapping him with those hideous, dry clicks. It paced somewhere to his left, then shifted to his right, circling the chamber with lazy confidence. It had all the time in the world.

  Ethan backed toward the wall, trying to make himself small. Useless. His breaths came too loud; his heartbeat was a beacon.

  [Heart Rate: 178 BPM | Oxygen Use Critical]

  His vision swam with heat-shimmer shapes he knew weren't real.

  He pressed his forehead to the cold rock and whispered, “Maria… I’m sorry.”

  A soft slosh rolled from the lake.

  Ethan stiffened. That wasn't the first monster. That sound came from deeper water, the kind only something enormous could displace. He turned his head toward the shoreline, listening hard through the ringing in his ears.

  The lake churned again.

  Not violently, and not fast. Something lifted beneath the surface with slow, implacable confidence. A deep thud traveled through the water, up the stone, and into Ethan’s boots, as if the cavern floor itself had a pulse.

  “CelestOS,” Ethan whispered, barely forming the words. “Tell me I’m wrong.”

  CelestOS: Hydrological displacement is increasing. Something very large is rising.

  His blood turned cold. “A second one?”

  CelestOS: Affirmative. Density suggests a significantly larger mass.

  The first monster screeched: short, sharp, and defensive.

  Ethan swallowed, throat tearing as he forced air through it. “They… do they know each other?”

  CelestOS: Unknown.

  The water detonated upward.

  A massive swell broke the surface, sending sheets of cold spray across the cavern. Ethan shielded his face instinctively, though there was nothing to see. He heard the second creature’s emergence: the cracking of stone under unimaginable weight, the wet grind of plates unfolding, and a low, resonant rumble that felt impossibly ancient.

  Two monsters.

  One between him and the lake.

  One rising from the lake.

  And no exit.

  A sick, hollow calm settled over him. His hands trembled, but the rest of him went still. There was nothing left to do, no way forward, and no way back.

  The first monster slunk nearer, claws scraping a slow circle around him. It hissed toward the shoreline, a warning or a challenge (he couldn't tell).

  The second answered with a low, rolling boom that pushed a wave of water out across the stone.

  Ethan whispered, “Not like this… not in the dark.”

  CelestOS’s voice then broke through, sharper than before.

  CelestOS: Ethan, incoming energy anomaly is behind the hydrological mass. Origin is unknown.

  “What? What doesn't that mean?” Ethan breathed, turning blindly toward the lake.

  CelestOS: Energy spike is irregular. Range is increasing. I can't—

  A pinpoint of light cut across the dark.

  Tiny and gold-white, like the first spark of a welding torch.

  Ethan blinked. “What—who—”

  The light sharpened becoming a beam. And then the world exploded.