The violent pounding outside continued.

Once...

Twice...

Then it suddenly stopped.

Silence filled the dark elevator.

But that silence was far worse than the noise itself.

Sako Hido stood motionless, his hand still resting on the hilt of his short sword.

Meanwhile, Haro Saki nervously glanced around.

«"Tell me that's part of the security system..."»

Sako didn't answer.

Then—

The red emergency lights suddenly came to life.

A blood-red glow reflected across the narrow metal walls.

And at that moment...

Long trails of blood appeared across the elevator door.

As if something had dragged its body outside.

Haro lowered his voice.

«"That's not a normal monster..."»

A sharp metallic sound echoed.

And very slowly...

The elevator doors began to open.

Outside the elevator...

Darkness filled the underground corridor.

But within the faint crimson light...

Something was standing there.

A distorted human body.

One arm stretched far beyond normal proportions.

Torn flesh.

And only a single eye slowly turning toward Sako.

But the most terrifying thing...

It was smiling.

A human smile.

Haro froze in place.

«"Impossible..."»

The creature took a slow step forward.

Then that distorted voice emerged again.

«"S... a... k... o..."»

Haro's eyes widened in shock.

While Sako continued to watch it with chilling calm.

---

Suddenly—

The creature lunged forward with terrifying speed.

Sako reacted instantly, drawing his short sword and severing the creature's arm with a single strike.

Black blood splattered across the walls.

But the creature didn't scream.

Instead, it began to laugh.

A broken...

Inhuman laugh.

Haro quickly stepped back.

«"What the hell is that thing?!"»

Sako kept his eyes fixed on it.

Then he noticed something that made him pause.

Engraved into the creature's neck...

Was a Roman numeral.

XIII

Specimen 13.

---

The creature began moving strangely.

Not like a monster...

But like a human trying to remember how to walk.

Then it suddenly stopped in front of Sako.

And slowly moved closer.

«"You... succeeded..."»

Sako's eyes narrowed slightly.

But before he could speak—

A massive alarm erupted throughout the underground facility.

The red lights began flashing violently.

A mechanical voice echoed through the complex.

«"Warning.

Experimental specimen has escaped.

Black-Level Threat."»

Haro looked up in shock.

«"Black-Level...?!"»

But the creature used that moment to leap into the darkness with frightening speed and vanished completely.

Silence returned to the corridor.

Then Haro began catching his breath.

While Sako continued staring into the darkness where the creature had disappeared.

---

Several minutes later...

The two entered one of the nearby rooms within the underground laboratory.

The room was filled with:

- Massive glass containment tanks

- Remains of old experiments

- Ancient machines that were somehow still operating

But the worst thing...

Was the files.

Hundreds of files.

Haro hurried toward them and began searching through the stacks nervously.

Then he suddenly froze.

His expression completely changed.

Slowly, he turned toward Sako.

In his hands...

Was an old black file.

Written on the cover were the words:

Subject 0

Sako Hido

Silence filled the room.

And Sako...

Simply fixed his gaze on the file without moving.This chapter creates a darker mystery than the previous ones, especially with Specimen XIII recognizing Sako and the revelation that Sako himself is Subject 0.