C-4: Sunless World

The old lady stepped forward first, slow and stiff, but steady. Her hand rested lightly on the child's shoulder, as if anchoring him to the Earth. The boy, maybe eight years old, clutched the corner of her sweater. His fingers were small and pale, gripping the fabric like a lifeline. He peeked out from behind her side, eyes darting left and right at the street beyond.

Outside, the "people" still moved.

Some walked in slow, broken lines.

Some just stood and stared.

Their eyes were not right.

The child knew it too. You could see it in how he held his breath. You could feel it in how tightly he grabbed that worn sweater.

Kim Jisoo said nothing as he took the lead. His fingers wrapped around the handle of his knife hidden in his coat. The tension in his body was a steel wire pulled tight. Every step forward was a decision. Every movement a gamble.

The three of them walked out of the apartment building and slipped into the shadows of the alley behind.

The sky hadn't changed.

Still that dead grey.

Still too quiet.

Jisoo moved carefully, keeping close to walls, taking back alleys and side routes. His ears strained to hear every footstep behind them. He kept glancing over his shoulder—watching for anything out of place.

More than once, he caught the boy looking at him.

Not scared.

Studying.

As if trying to understand what kind of person Kim Jisoo was.

He didn't know what that meant. But he didn't like being watched.

Not right now.

Not while danger hung so thick in the air it was like breathing in static.

It took them an hour and a half to reach the edge of the forest trail.

The old woman was breathing heavier now, but she never asked to stop. The boy didn't complain once.

When they reached the camouflaged service door hidden behind a thicket of brush and stone, Jisoo tapped the hidden keypad with silent precision. The door opened with a hiss of pressure.

The child flinched. The woman didn't.

They stepped inside.

Concrete walls. Red backup lights. Silence.

Jisoo sealed the door behind them and led them through the winding tunnel.

The boy couldn't stop staring. First at the reinforced hallway. Then at the wall-mounted cameras. Then the electronic locks.

He didn't ask questions. But his eyes were drinking in everything.

When they reached the final steel gate, Jisoo paused and placed his palm on the scanner.

The lab opened like a vault.

Inside, the air changed—cool, filtered, clean.

The main chamber of Black Hollow was exactly what Jisoo had designed over six years ago: a secure sanctuary, deep beneath the city. A command center. Not just to survive—but to understand.

Walls of screens flickered silently with data. Radiation maps. Thermal grids. Signal spectrum analysis. There were worktables stacked with hardened tools, monitors running live feeds from hidden cameras around Seoul, and a sealed lab door to the right marked with a coded pad.

The child stopped in his tracks, jaw slightly open.

He stepped forward slowly, his hands dangling awkwardly by his side.

"Is this… yours?" he asked softly.

Jisoo didn't answer. He walked ahead and pulled open another door on the left wall.

"Follow me."

The hallway beyond was narrower, more quiet. At the end was a simple grey panel door. Jisoo opened it and stepped aside.

The boy entered first.

And froze.

The room was… warm.

Unlike the rest of the lab, which was stark and mechanical, this room was alive with color and care.

The floor was soft pinewood laminate, covered by a thick cream rug. The walls were painted a soft ocean blue, with gentle white clouds painted in scattered shapes across the ceiling. Fairy lights were strung along the upper walls, dim and cozy. On one side sat a low twin bed with a pale yellow blanket and a plush navy headboard. Neatly arranged shelves held books—children's stories, graphic novels, and even some old educational games.

A small desk with colored pencils and blank paper sat by the window (the "window" being a cleverly backlit screen that mimicked real sunlight, complete with a slow cycle of dawn and dusk).

A bean bag sat in the corner, next to a small bookshelf filled with picture books and a few plush animals.

There was even a mural painted across the left wall—a fox curled up under a tree, eyes closed, surrounded by stars.

The child didn't move. He just stared.

His lips parted slightly. His hands fell away from the sweater hem.

The old lady stepped in after him, blinking slowly.

She whispered, "You made this?"

Jisoo didn't nod. Didn't explain.

He just said, "He can stay here. It's sealed. Monitored. The air's filtered separately."

The woman looked back at the boy. His hand drifted to the fox on the mural, gently tracing the painted fur with his fingertips.

Jisoo stepped out and left them there.

Back in the main lab, Jisoo stared at the screen in front of him.

His own pulse had steadied.

He didn't plan to tell them this room was his own idea from years ago—when he briefly worked on a private commission for a luxury bunker design firm.

Back then, everyone wanted steel and concrete, guns and rations. But he'd thought about the other part of survival.

What about kids?

What about the ones who lost everything?

He'd used leftover paint, experimental faux sunlight panels, and salvaged decor from old design contracts. Tested child-safe materials. Measured room acoustics. Optimized airflow.

He never imagined anyone would see it.

It was just… something he had to build.

A corner of humanity inside a storm.

Fifteen minutes later, the old lady stepped into the lab again.

Jisoo didn't turn to her.

She said, "Thank you."

He didn't reply.

She stayed for a moment. Watching the screens.

Then: "My name is Ji-won. His name is Haru."

Jisoo nodded once. "Kim Jisoo."

"That room... it's beautiful," she said.

"It's functional."

She smiled sadly. "You don't have to pretend not to care."

He said nothing.

When she turned to leave, she paused. "He's already trying to figure out how your monitors work."

Jisoo's jaw twitched.

"I noticed," he muttered.

Ji-won gave him one last look. Then left.

That night, or whatever passed for night in this false sunless world, Jisoo sat in the corner of the lab, watching the screen feeds.

He replayed the moment when the child—Haru—first saw the lab.

The way his eyes lit up.

The way he followed every wire, every cable, like he was trying to learn its secrets.

And he thought… maybe this wasn't a burden.

Maybe bringing them here had been the smartest thing he'd done since the sun died.

But even as he thought that, something else gnawed at his gut.

The bedroom door in his old apartment.

It was still closed.