Chapter 74
Chapter 74
The first thing I did after returning to the workshop was place one of the recovered mechanical arms onto the workbench.
“Let’s see.”
Maybe it was because I had finally discovered my aptitude after ten years of living as a porter.
Whenever moments like this came, my motivation surged.
Smacking my lips, I picked up a tool and carefully began removing the screws.
This was an object made by humans, not by the system.
If I wanted to understand how they thought and how they solved problems, I had to dismantle it with my own hands.
Click. Clack.
As the outer casing came off, the complex internal structure revealed itself.
“…Oh.”
A quiet admiration escaped me.
The exterior looked crude, but the inside was astonishingly precise.
Of course, the core parts—gears and crank mechanisms—were not perfect spheres or straight lines like the items I created.
Judging from the item information visible on the parts, an ability user had clearly manufactured them, but they likely lacked precision machining abilities.
Still, the way those rough parts were designed to mesh together perfectly without a single gap was remarkable.
This wasn’t a design made sitting at a desk.
It contained knowledge from before the apocalypse.
And hundreds of battles and thousands of adjustments had been layered on top of that knowledge.
A brutal record of survival.
I examined the fingers closely.
The structure was simple.
Inside the forearm was a magazine slot and feeding mechanism.
Each of the five fingers functioned as a separate barrel.
“I’d like to call this the Finger Gatling.”
What interested me most was the barrel mechanism.
When the arm was bent, the barrels were hidden.
But when the arm extended and the fingers spread, they snapped outward with a sharp click.
Foldable Barrel.
Clearly designed to improve portability during normal use and extend range and accuracy during combat.
“How about the firing mechanism?”
The structural analysis was complete.
Now I ran a simulation.
Would all five barrels fire simultaneously?
No.
Bang! Bang! Bang-bang!
There was a firing sequence.
The thumb fired first.
As recoil began lifting the muzzle upward and pulling the arm left—
The little finger fired, pushing recoil to the right.
Then the index and ring fingers fired simultaneously, stabilizing vertical sway.
Finally the middle finger fired, finishing the sequence.
A precise firing pattern divided into 0.1-second intervals.
The reason was clear.
Zero recoil.
If rifle rounds were fired rapidly with one hand, recoil would twist the arm or send the aim skyward.
To counter this, they had devised a crazy method—
Canceling recoil with opposing recoil.
This wasn’t just mechanical engineering.
It was an art that pushed the limits of human muscle endurance while perfectly synchronizing machine timing.
If I had tried to build this myself, I never would’ve thought of something like this.
The system suggested optimal efficiency.
But this kind of irregular creativity came from human desperation.
Wow.
This single mechanical arm told the story of what kind of hell they had survived for the past ten years.
“Still, there’s plenty to learn.”
I switched on the workbench lights and entered full research mode.
The Machine Society’s approach was impressive.
But it also had clear limitations.
There isn’t enough internal space.
Their prosthetic arms replaced the entire limb, so they at least had some room inside.
Even then, there wasn’t nearly enough space to install both rifle ammunition and a grenade launcher.
So they divided roles.
Two soldiers with mechanical arms provided firepower.
One soldier with mechanical legs handled mobility and ammunition supply.
That was why prosthetic legs were optimized for movement.
Those soldiers usually used blades instead of firearms.
My Mechanical Reinforcement Exoskeleton was a suit worn over my arms.
And since my actual arm remained inside, the internal space was even more cramped.
There was no room for complex feeding systems or long barrels.
“Tsk. See? Having real arms is a disadvantage, Boss. Why not just cut them off and replace them with machines? I don’t even have arms and I’m doing great.”
Picker teased from the monitoring feed.
Normally I would have smacked him.
But right now ideas were flooding my mind.
If there’s no space… then I’ll make space.
The real problem was the rigid metal barrel.
To fire rifle rounds required 5.56 mm caliber.
To fire grenades required 40 mm caliber.
To install both, my forearm would have to be as thick as a thigh.
“What if the barrel could stretch like rubber?”
A material flexible enough to expand, yet capable of becoming harder than steel at the moment of firing.
My mental database began spinning rapidly.
Then a name surfaced.
Stone Eater.
An E-Rank mutant that had terrified people hiding inside buildings during the early days of the apocalypse.
Those creatures chewed through concrete walls like crackers and slaughtered anyone inside.
Because of them, cities had become mountains of rubble.
Nowadays they were ignored because hunting them offered little value.
But their digestive organs hid a secret.
Adaptive Stomach.
Normally their bodies remained compact for agility.
But when swallowing rocks larger than themselves, their stomach expanded like a balloon.
At the same time the stomach lining hardened like stone to prevent sharp rebar from piercing it during digestion.
Which meant—
It expanded.
And hardened.
The perfect biological tube I had been searching for.
“This is it.”
I immediately opened a blueprint.
Instead of heavy steel frames, I designed the exoskeleton skeleton using lightweight and strong titanium alloy.
Then, within the dead spaces of the frame, I implanted processed Stone Eater organs.
Normally they would contract and remain hidden like blood vessels.
During firing they would expand to the required caliber.
Just before firing, mana would be injected to trigger instant hardening, giving durability equal to steel barrels.
And because the tissue came from mutants, it was also heat resistant.
No overheating problems.
One barrel capable of firing rifle rounds, grenades, or even shotgun shells.
The ultimate weapon.
Hybrid Arm Cannon.
“Haha… this is insane. This might actually work.”
The problem was control.
Unlike prosthetic arms with neural connections, I was wearing an exoskeleton.
Controlling this variable system would require extremely delicate adjustments.
I began calculating formulas and drawing circuit diagrams at a frantic pace.
The food was already on the table.
I just needed a spoon.
“Uh… Boss?”
Picker cautiously interrupted.
“The encirclement formation is complete. The drones are waiting and their batteries are draining. Aren’t you going to give the attack order?”
But I heard nothing.
My mind was filled with mana circuits and biological integration algorithms.
“If the signal is amplified here… no, we need a backflow prevention valve…”
Watching Kang Sinhyeok muttering alone in the workshop, Picker shook his head.
“Engineers really are hopeless…”
Meanwhile — Dohwa-dong Waste Hill
Boom! Boom!
Following Yoon Imsu’s instructions, the Ground Exploration Device slammed its hydraulic cylinder into the ground.
Rhythmic vibrations traveled deep into the waste hill’s geological layers.
“Stop.”
Yoon Imsu raised his hand.
Behind his goggles, his eyes gleamed coldly.
Of the three locations, he believed the Dohwa-dong waste hill had the highest probability of hiding the Bomber.
Based on his estimate of the enemy’s forces, the other two locations might be production bases.
So he personally came here, bringing Jibgae with him.
“They should appear soon.”
As soon as he spoke—
A beastly howl erupted from the garbage piles.
Dozens of Contaminated Wild Dogs burst out.
A normal expedition team might have panicked.
But the huge man standing beside Yoon Imsu did not move.
Jibgae, the Machine Society’s operations commander.
His right arm was not human.
From shoulder to fingertip extended a massive steel claw composed of hydraulic cylinders and gears.
On his back was a heavy diesel engine protruding like a turtle shell, spewing dark smoke.
“Grrr!”
One wild dog lunged for Jibgae’s throat.
He didn’t even turn his head.
Pssshh—
The engine roared.
His arm disappeared from sight.
Crunch.
“Yelp!”
The dog was smashed into the ground, its body folded in half.
Jibgae’s steel claw had grabbed its waist and crushed it instantly.
It wasn’t merely brute strength.
It was mechanical power amplified by engine-driven hydraulics.
“Pathetic.”
Jibgae tossed the twitching corpse aside like trash.
Heat shimmered around the heavy armor covering his body.
The engine generated intense heat, forming a thermal barrier around him.
“That tin can is pretty strong.”
I had paused my research and was watching the situation through the monitor.
“The heat is the real problem.”
It wasn’t just hot.
The temperature difference caused air density changes, creating convection currents.
In that condition, light projectiles like poison darts or anesthetic needles would likely deviate off course.
If I got careless, their hidden trump card might hit me unexpectedly.
I needed to test them first.
“Picker.”
“Yes, Boss!”
“Let’s draw out their abilities.”
“Oh ho. Sabotage operation? That’s my specialty!”
The Dohwa-dong waste hill was a place humans avoided.
Which meant it was essentially an apartment complex for mutants.
“Operation name: Morning Call.”
Following Picker’s order, the Honeybee squadron scattered across the hill.
They targeted hidden mutant nests.
Ping. Ping.
Small projectiles dropped from the drones and exploded at nest entrances.
They had no explosive power.
Noise Induction Rounds.
Instead, high-frequency sound waves shook the entire ruin.
“Screeeech!”
“Greeeek!”
Furious mutants burst out after their sleep was disturbed.
Dozens rushed toward the sound source.
What they saw—
Was Jibgae and Yoon Imsu standing there.
“What the—?!”
Yoon Imsu stared at the red dots on his tactical goggles in shock.
More than thirty mutants were approaching from all directions.
This wasn’t coincidence.
It was a deliberate wave attack.
“So you finally responded!”
“It’s a trap! Combat positions!”
Yoon Imsu shouted.
But already a swarm of Giant Rats surged forward like a tidal wave.
Then Jibgae stepped forward.
“Bomber… for someone with such a fearsome reputation, you’re annoyingly indirect.”
He twisted a valve behind his back.
Rumble—
The engine screamed.
“Burn.”
Exhaust Storm.
Fwoooosh!
It wasn’t only the exhaust pipe.
High-pressure superheated steam and black smoke blasted from every gap in his armor.
“Screee!”
“Gyaaa!”
The charging Giant Rats were blown backward instantly.
Their skin cooked red.
Their eyes burst from the heat.
Everything within a five-meter radius was pushed away and scorched.
An absolute defensive barrier.
And a close-range area attack that boiled anything nearby.
Within the thick steam, Jibgae looked like a demon emerging from hellfire.
“Oh.”
Watching from the monitor, I smiled.
“So that was his hidden move.”
If I had fired anesthetic or poison darts recklessly—
They would have been deflected by the steam pressure or melted by the heat.
My caution had paid off.
But at the same time—
His defeat was already certain.
Emitting heat meant he was extremely vulnerable to heat-reactive effects.
“Hahaha! What’s with that tin can? I thought he had something impressive. Turns out he’s just a walking pressure cooker!”
Picker laughed.
I nodded.
“Yeah. No need to prepare anything special.”
Jibgae was clearly strong.
Unfortunately for him—
He was a terrible match against me.