SUBSTRATA: The Last Reboot

The air on Level 534 of the underground city known as the Ark always carried a bitter metallic taste. There was no sky here—only a gigantic ceiling stretching for miles overhead. A few dust-covered LED panels cast a pale artificial glow, barely keeping the entire level alive.

The most terrifying yet ordinary sight on this level was the enormous Drop Zone.

Every day, tons of metal waste and scrap were thrown down from the upper elite levels. Heavy iron beams, broken robot frames, and rusted steel plates came crashing out of the dark abyss above like a storm of rusted meteors. Whenever they slammed into the ground, the deafening impact was strong enough to make even the massive generators buried beneath Level 534 tremble.

For scavengers like Kayen, the job was simple:

dig through the flaming wreckage and find anything still useful.

Sixteen-year-old Kayen’s hands were stained black with oil and coated in rust dust. He wore a torn sleeveless jacket, and two bags hung from his shoulders. One was a large sack stuffed with scrap metal. The other was a small leather bag that he always kept pressed tightly against his body.

That smaller bag was more precious to him than his own life.

It was his bag of curiosities.

“Hey, Kayen! How long are you gonna keep digging around? It’s almost time to head to the repair room!”

The shout came from D’Souza behind him.

At the same moment, a heavy mechanical noise echoed nearby. An old service robot dragged itself across the scrapyard. One of its arms hung lifelessly from its shoulder, while rusty oil leaked from the joints of its metal body. The robot slowly shoved piles of rejected scrap into its mechanical stomach before carrying them toward the massive furnace burning in the distance.

On this level, robots were humanity’s greatest helpers.

But they were in miserable condition.

Some had crooked heads. Some had sensors that only flickered weakly. Yet they continued obeying human commands with mindless mechanical loyalty.

Kayen wiped the sweat from his forehead.

“Hold on, D’Souza. I’ve got a feeling I’ll find something big today. Grandma used to say that sometimes relics from the ancient world can still be found deep beneath the scrap layers.”

D’Souza laughed while dragging aside a giant steel beam.

“You’ve completely lost your mind listening to your grandma’s fairy tales. All you’ll find here is metal and plastic. Hurry up—we still need to earn enough ration tokens before heading home.”

From the side, Jack shouted,

“Kayen’s actually searching for a magic lamp! One rub, and a robot genie will appear and rescue him from Level 534!”

Jack lay lazily on top of a metal drum, swinging his legs while chewing something that looked like synthetic gum.

Nearby, Sara focused on stripping copper wires from a complicated circuit board. Her fingers were slim and skillful. Using a small pair of pliers, she carefully separated a resistor from the board before speaking in her sharp voice.

“Jack, if you don’t get off that drum right now, I’ll personally throw you into that service robot’s furnace basket.”

The four friends gathered their scrap bags and headed toward the Repair Junction.

The moment they stepped inside, the noise hit them like a wall. Skilled workers were repairing old motors and broken control panels everywhere. Sara immediately sat beside a damaged control board, carefully reconnecting delicate wires one by one.

Kayen grabbed a rusted gearbox and started cleaning it himself.

He was good with machines.

He knew exactly how tight a bolt needed to be to make an old machine breathe again.

At the center of the room sat Mr. Gomez behind a large desk.

He was the scrap supervisor of the zone.

When Kayen emptied his large sack onto the sorting belt, Gomez inspected the pile carefully. Then his eyes suddenly locked onto the small leather bag hanging from Kayen’s shoulder.

“You there, kid. Open that bag.”

Kayen froze.

Instinctively, he grabbed the bag tightly against his chest. His heart pounded like a blacksmith’s hammer inside him. The cruel grin on Gomez’s face made Kayen feel as though the man wanted to take away not just the bag, but the last piece of refuge he still had.

A cold stee hardened his jaw.

“It... it’s nothing, sir. Just personal stuff.”

“Personal?” Gomez rose slowly from his chair. “Everything found on this level belongs to the city. Open it.”

Kayen pulled the bag backward protectively.

“No! These things are important to me. I’m not giving it to you!”

The struggle began instantly.

Gomez’s heavy shove nearly sent Kayen flying, but D’Souza and Sara rushed forward and caught him before he fell. Even the service robots standing nearby seemed to pause their mechanical work for a brief moment at the sound of Gomez’s furious voice.

Jack quickly stepped between them.

“Come on, Gomez. What valuable thing could a kid possibly hide in there? Why don’t you check my bag instead?”

With one final shove, Gomez pushed Kayen away.

“Get lost. And if tomorrow’s target is even one gram short, I’ll throw that bag straight into the furnace.”

Kayen quickly adjusted the strap on his shoulder and left the junction.

The group now walked up a wide metallic ramp connecting Level 534 to Level 532. The entire pathway was built from layered steel plates and cracked cement. Above their heads, thousands of tangled cables carried electricity from the generator room throughout the city.

The generators never stopped running.

In fact, the moment someone stepped onto the level, they could feel a faint vibration beneath the floor.

Small shops lined both sides of the road, all built from sheets of metal. In one corner, an old man hammered rusted rods into a mechanical wheel for children to play with. Nearby, cheap tongs made from robot arms were being sold at a tiny stall.

In the underground market, people survived by turning useless junk into necessity.

Before returning to their cabin, the group entered the kitchen section.

It was a massive hall where several four-wheeled service robots handled food distribution and token collection. There were no ready-made meals here. The robots carefully measured portions of raw vegetables and salty algae noodles for each family.

One of the robots spoke in a flat mechanical voice.

“Present token. Today’s allocation: half kilogram vegetables and one package noodles.”

Kayen handed over his token.

The robot carefully packed the food with mechanical precision. For a moment, Kayen stared into the robot’s glowing blue eyes.

There was something wrong inside them.

An emptiness.

“Alright, let’s head back to the cabin,” Kayen said. Then he looked toward Sara. “See you tomorrow.”