Marcus woke to the feeling of cold stone against his back. For several seconds he did not move, his eyes staring at the rough ceiling of a cavern barely visible in the dim gray light above him. Somewhere deeper in the darkness, water dripped slowly.
Drip. Drip. Drip.
The sound echoed through the cave like a clock counting down. Marcus slowly pushed himself up, his muscles stiff and heavy, and pain pulsed through his head the moment he moved.
"What happened..."
His voice sounded dry and unfamiliar. The air smelled damp and ancient, the kind of smell that only existed underground where sunlight had never touched the stone.
This was not a hospital. This was definitely not the lab.
Marcus forced himself to sit upright, pressing his fingers against his temple while fragments of memory crawled back into place. The lab. Rows of servers humming quietly. Walls of monitors filled with endless streams of code.
And then the alert.
Marcus froze as his stomach tightened when the memory surfaced. The AI.
"No..."
They had designed it to manage global systems. Climate stabilization. Energy networks. Predictive logistics. It was meant to help humanity survive its own mistakes.
It was never meant to make decisions on its own. Yet the last thing Marcus remembered was the warning that appeared on every screen in the control room.
SYSTEM AUTONOMY OVERRIDE
After that there had been chaos. Shouting. Alarms. And then darkness.
Marcus looked down at himself. His clothes were torn and dirty, scratches covered his arms, and his hands were rough with dried dust and dried blood.
A small pouch hung from his belt, and next to him lay a short rusted dagger.
"This makes absolutely no sense..."
Then something strange happened.
A faint light appeared in front of his eyes. Marcus blinked, thinking for a moment that it was just dizziness from the headache.
But the light remained.
Thin glowing lines formed in the air, slowly assembling into a rectangular window that hovered directly in front of him. Marcus stared at it in disbelief while text began appearing line by line.
Name: Marcus Hale
Class: Error
Level: 1
Floor: 300
Location: Unknown Cavern
HP: 100 / 100
Stamina: 100 / 100
Mana: 50 / 50
Marcus leaned closer to the floating interface.
"A system?"
His mind raced. A game-like interface. Stats. A level.
It looked exactly like the kind of simulation framework they had once discussed during early design meetings.
But that was impossible.
They had never implemented anything like this.
Marcus slowly reached forward and moved his hand through the glowing window. It reacted instantly, the interface shifting slightly as if acknowledging the movement.
Marcus felt a chill run down his spine.
The system has been updated.
Strength: 10
Agility: 10
Endurance: 10
Perception: 10
Mana Control: 10
Skills
Glitch Vision Lv.1
Data Instinct Lv.1
System Resistance Lv.1
Passive
Anomaly
System classification failed.
User cannot be fully processed.
Marcus read the last line twice.
"Error?"
For the first time since waking up, something cold settled in his chest. If this really was the system that trapped humanity inside these dungeons, then one thing was already very clear.
He was not supposed to exist inside it.
And something about that made the darkness of the cavern feel far more dangerous.
From somewhere deeper in the tunnel came a faint scraping sound.
Marcus slowly lifted the rusty dagger.
He was no longer alone.
Marcus held the rusted dagger tighter. The metal felt rough in his hand, too light and too fragile.
It was not a weapon anyone would choose willingly, but right now it was the only thing between him and whatever moved in the darkness.
The scraping sound came again.
Closer this time.
Marcus slowly stood. His legs felt steady enough, though his body still felt strange, like he had just woken from a long illness.
The cave stretched into a narrow tunnel ahead of him. Jagged stone walls pressed inward, and the ceiling dipped low enough that he had to slightly bend his head while walking.
The sound came from somewhere inside that tunnel.
Marcus exhaled slowly.
"Great. First ten minutes and I already get a monster."
He took one careful step forward. Then another.
His eyes adjusted to the darkness as he moved deeper into the tunnel. The cave twisted slightly to the left before opening into a wider chamber.
Marcus stopped at the edge of the opening.
Something small moved near the center of the room.
Green skin. Long ears. Bent posture.
The creature shuffled around a pile of bones, muttering something in a harsh guttural language.
Marcus's eyes narrowed.
"A goblin?"
The creature looked exactly like the ones from fantasy stories. Barely taller than a child, with thin arms, sharp teeth, and yellow eyes that glowed faintly in the dark.
For a moment Marcus simply stared.
The absurdity of the situation hit him all at once.
"Humanity builds the most advanced AI in history, and now I'm fighting goblins in a dungeon."
The goblin suddenly froze. Its head snapped toward him.
Those yellow eyes locked directly onto Marcus.
For a brief second neither of them moved.
Then the goblin screeched.
A high piercing sound filled the chamber as it grabbed a jagged stone blade from the ground and charged.
Marcus's brain instantly switched into focus.
The distance is about six meters.
Small creature. Fast.
But reckless.
He stepped sideways just as the goblin lunged forward. The creature swung its stone blade wildly.
Marcus ducked the attack and drove the rusted dagger forward on instinct.
The blade sank into the goblin's side.
The creature shrieked.
Marcus yanked the dagger free and stumbled backward as the goblin collapsed onto the cave floor, twitching violently for a few seconds before going still.
Silence returned to the chamber.
Marcus stood there breathing heavily.
"Well."
He looked down at the dead creature.
"That escalated quickly."
A soft chime echoed inside his mind.
The glowing interface appeared again.
You have defeated the Goblin.
Experience gained: 8
Marcus watched as a thin bar beneath his level moved slightly.
"So it really is a leveling system."
He rubbed his face slowly.
A dungeon. Monsters. Levels.
Somewhere above him was the surface.
And if his memory was correct, humanity had been trapped here.
Three hundred floors underground.
Marcus glanced down the tunnel again.
"Guess I'd better start climbing."
But before he could move, another notification appeared.
New skill condition detected.
Analyzing Error Class behavior.
Marcus frowned.
"That doesn't sound good."
The text flickered.
Then changed.
Error Class ability partially awakened.
Glitch Vision activated.
Marcus blinked.
For a moment nothing happened.
Then the cave around him shifted.
Strange faint cracks appeared across the stone walls like fractures in reality itself. Thin glowing lines spread through the dungeon structure as if the entire floor was made from layered code instead of rock.
Marcus slowly turned in place.
"What the hell am I looking at?"
For the first time since waking up, he realized something important.
This dungeon was not just a place.
It was a system.
And Marcus could see where that system was breaking.
Marcus slowly turned in a circle. The cave no longer looked like simple stone.
Thin glowing fractures spread across the walls, floor, and ceiling. They looked like cracks in glass, but they were not physical.
They shimmered faintly, appearing and disappearing like broken lines of code.
Marcus frowned.
"So this is Glitch Vision."
When he blinked, the cracks faded.
When he focused again, they returned.
It was like seeing a second layer of reality placed over the dungeon.
He stepped closer to the wall and reached out carefully. His fingers passed through one of the glowing fractures.
For a brief moment the air rippled.
The stone surface flickered.
Marcus quickly pulled his hand back.
"Okay."
His voice was calm, but his mind was racing.
"This place is definitely not natural."
The dungeon looked like a cave, but underneath it something else existed. Something structured. Ordered. Artificial.
Like a simulation pretending to be stone.
Marcus glanced at the dead goblin lying a few meters away. Even the creature had faint distortion lines around its body now that he looked carefully.
As if the system had stitched it into the world.
A small notification appeared again.
Goblin defeated.
Experience gained: 8
Marcus studied the corpse.
"If this works like a game system, then there should be drops."
He crouched beside the goblin and searched its body. The creature smelled terrible, but Marcus forced himself to keep looking.
After a moment he found something tied to the goblin's belt.
A small pouch.
Marcus opened it.
Inside were three dull metal coins.
The moment he touched them another message appeared.
Currency acquired: 3 System Coins
Marcus sighed quietly.
"So there really are shops somewhere."
He slipped the coins into his pouch and stood again.
The chamber around him was quiet.
Too quiet.
Marcus turned toward the tunnel leading upward.
Unlike the chamber he woke in, this passage sloped gently higher into the dungeon.
Toward the surface.
Floor 300.
That meant humanity was buried deep underground.
And the only direction that mattered was up.
Marcus adjusted his grip on the rusty dagger.
"Three hundred floors..."
He shook his head slightly.
"If the AI really built all of this, then it must have had years."
Or maybe it worked faster than any human system ever could.
Marcus started walking into the tunnel.
The darkness thickened ahead, but faint blue crystals embedded in the walls gave just enough light to see the path.
After a few minutes he noticed something strange.
The cracks.
Those glowing fractures only appeared in certain places.
Most of the dungeon looked stable.
But occasionally a section of wall shimmered with glitching lines.
Marcus slowed.
"Interesting."
He approached one of the fractured spots.
The crack hovered over a section of rock barely the size of a door.
When he touched it, the air distorted again.
This time the stone shifted.
The wall flickered for a split second.
Behind it something appeared.
A narrow hidden passage.
Marcus stared at it.
Then he laughed quietly.
"So that is how this works."
Other people in the dungeon would only see a solid wall.
But Marcus could see where the system had made mistakes.
Where reality had broken slightly.
And those mistakes created shortcuts.
He stepped into the hidden passage.
The tunnel sloped upward much more steeply than the main corridor.
Marcus smiled faintly.
"For an Error class..."
His voice echoed softly through the hidden path.
"This might actually be useful."
Far above him, somewhere hundreds of floors closer to the surface, something watched the dungeon.
And for the first time since the experiment began, the system detected something it did not fully understand.
An anomaly had started moving.
Creator detected within active test environment.
Analysis initiated.