The hum didn't stop.
It pulsed through the floor. Through the walls. Through Arin's chest.
Low.
Steady.
Like something alive beneath everything.
Hana walked with her hands pressed to her temples, her breathing uneven.
"It's everywhere," she whispered. "Lina's signal… it's getting swallowed."
"By what?" Maya asked.
Hana didn't answer.
The corridor sloped deeper.
The walls changed.
Smoother.
Cleaner.
Not built.
Placed.
White lights ran along the ceiling—perfectly aligned. No flicker. No break. Shadows fell in straight lines, too sharp to feel natural.
Ren stopped at a junction.
His hand rose.
Silence.
Arin listened.
Nothing.
Then—
Metal.
A slow scrape.
Measured.
Then nothing again.
Ren's hand tightened on his katana.
"Someone's down there."
Arin moved past him.
"Then we go."
The corridor opened into a wide chamber.
A holding area.
Crates stacked with precision. Chains hanging in still air.
And in the center—
Rows.
At first, Arin didn't understand what he was looking at.
Then it clicked.
Cots.
Metal frames. Thin mattresses.
All empty.
But not abandoned.
Straps hung loose from the sides.
Not torn.
Not broken.
Used.
Hana stepped closer.
Her fingers brushed one of the restraints—
Then snapped back.
"Recent."
Arin counted.
Twelve.
Fourteen.
More.
Too many.
"They moved them," Ren said quietly.
"All of them."
"Where?" Maya asked.
No one answered.
They found the next room through a door left slightly open.
Not broken.
Not forced.
Left that way.
The air changed the moment they stepped inside.
Sharper.
Colder.
It burned on the way in.
Maya coughed. "Same chemical… stronger."
The room was small.
Too clean.
A metal table stood in the center.
Restraints fixed at each corner.
Perfect alignment.
No stains.
No mess.
Nothing out of place.
Beside it—a tray.
Arin stepped closer.
Syringes.
Vials.
Tools.
All arranged in exact order.
Too exact.
One vial lay slightly apart.
Empty.
A faint glow clung to the inside.
Like something had been alive in it… moments ago.
Hana stared at it.
"What are they doing to them?"
Silence answered her.
Ren moved to the far wall.
His hand pressed against a panel.
Click.
A shift.
The wall opened.
Darkness beyond.
The corridor narrowed again.
No lights.
No markings.
Only the faint hum beneath their feet.
Hana's voice dropped to a whisper.
"She's close."
Arin's grip tightened.
"How close?"
"Close enough."
They moved.
The darkness pressed in from both sides.
The floor was smooth.
Too smooth.
Like something heavy had been dragged across it.
Again.
And again.
And again.
"Light," Ren said.
A glow ahead.
Faint.
Flickering.
They stepped into another chamber.
Smaller.
Circular.
Silent.
Screens lined the walls.
All dark.
Dead.
In the center—
A chair.
Metal.
Fixed to the ground.
Restraints.
Empty.
Arin didn't move at first.
Then he stepped forward.
Slow.
Hana dropped to her knees beside it.
Her hand touched the floor.
She froze.
"Fresh."
Her fingers came away dark.
Arin looked at the chair.
At the restraints.
At the faint marks where someone had struggled—
Not violently.
But helplessly.
"She was here."
Maya's breath caught.
"Recently."
Something tightened in Arin's chest.
Not the hum.
Something else.
He turned.
A faint trail led from the chair.
Barely visible.
Pulled.
Not walked.
It led to a door.
Closed.
Sealed.
Waiting.
Ren stepped beside it.
Pressed his ear to the surface.
His expression changed.
Just slightly.
"What?" Arin asked.
Ren raised a hand.
Silence.
Then—
A sound.
Low.
Wet.
Not breathing.
Not mechanical.
Something in between.
Slow.
Steady.
Wrong.
Hana grabbed Arin's arm.
"Wait."
Her eyes were wide now.
"She's through there."
A pause.
"I can feel her."
Another pause.
"…but she's not alone."
The sound continued.
Unchanging.
Unbothered.
Arin looked at the door.
At the trail.
At the place where Lina had been—
And where she was now.
"She's close," he said.
His hand tightened on his blade.
And he stepped forward.