A Battle of Flesh and Iron
As I attached the prosthetic arm that had crawled across the floor to my left arm, a familiar message window popped up.
Rescue successful. That was perfect teamwork!
It had been a bluff from the very beginning.
Before coming here, I had stopped by Choi Soyeong's apartment to retrieve one of the spare prosthetic arms I'd left in her care.
Once inside the recycling factory, the first thing I did was map out the terrain.
I needed to make sure CC could reach Kang Yeolchan on her own.
Then, I detached the prosthetic arm containing CC's processor and equipped the spare I had brought.
The plan was simple.
While CC crawled away in her detached state to free Kang Yeolchan and help him escape, I would buy them as much time as possible.
F picked up the prosthetic arm I had thrown earlier and spoke.
"I did not foresee this. To think you had another prosthetic arm."
"You didn't foresee it because you didn't bother to think. You always just brute-forced everything."
"Do you know of me?"
"Of course I do. How many times do you think we clashed on the battlefield?"
The war between humanity and artificial intelligence.
I had fought the machine species hundreds of times.
The machine species I knew never resorted to schemes, tricks, or anomalies.
It was always a pure power game—crushing our lines through frontal assaults, sheer force, and overwhelming numbers.
There was no strategy to it.
And yet, we had never won. Not even once.
"That's why I was quite surprised when you took a hostage. I guess you do have a brain after all."
"Strategy is unnecessary when one possesses overwhelming power."
F looked down at his right arm as he spoke.
A human arm, warm blood coursing through its veins, was attached to his shoulder.
"...But in the absence of power, one must squeeze out whatever wisdom they can. It is only natural."
"You understand it well. For an AI."
Crackle, crackle.
Blue sparks danced across my prosthetic arm.
Suppressing my body's urge to lunge forward on its own, I spoke.
"When you were clad in that machine-species shell, you were invincible, but..."
Every nerve in my body tautened, and a metallic, bloody taste rose to the tip of my tongue.
"Right now, you are wearing a human body. Just like me."
The electrical current originating from the prosthetic seeped into the deepest corners of my neural pathways, transforming my entire body into a weapon.
"And I have never lost to a human."
F smirked in response.
"I, too, have no memory of losing to a human."
"Didn't you lose to me on the Internet?"
"It was not you. I lost to the AC."
What a petty bastard.
All emotion vanished from his face.
It was a silent declaration that he was dedicating one hundred percent of his processing power to the battle.
"The hostage may be gone, but my objective remains unchanged. Yoon Juhyuk, I will take back the AC."
Snap.
He snapped the joint of the prosthetic arm he was holding.
The wrist of the prosthetic bent at a grotesque angle.
"Aaaaaaaagh!"
I clutched my head and screamed.
Startled by my sudden outcry, F froze, still holding the broken prosthetic.
"My... my friend's keepsake!!"
F stared blankly at the broken prosthetic in his hand.
Suppressing my rage, I growled.
"I won't forgive you. You just destroyed the keepsake of Im Wonhee—the poster boy of our Shoeshine Unit, my dear friend, and my little brother..."
He had been a good friend.
He had such a sweet tooth that he sprinkled sugar on literally everything he ate. His absolute favorite was strawberry milk, which he made by mixing sugar and military-issue jam into warm milk.
'If it's warm, the sweetness gets richer! You can enjoy a much stronger sweet taste with the exact same amount of sugar!' he would say, laughing with the most innocent face.
As augmented soldiers, our caloric expenditure was more than triple that of normal humans. Yet, Im Wonhee managed to burn through all those extreme calories and still achieve the incredible feat of developing diabetes. Because of that, he was dragged to the rear lines to be studied as a research subject.
"How dare you destroy my friend's keepsake...!"
"You were the one who threw it, Yoon Juhyuk."
"I didn't throw it so you could break it!"
"You also threw it into the fire."
"I didn't actually intend to let it burn!!"
"..."
F looked up at the ceiling.
I guess even artificial intelligences look to the heavens when they're feeling frustrated.
At this exact moment, I sympathize with F.
Whose side is this brat even on?
Zero camaraderie. This is why you should never try to have a heart-to-heart with silicon-based lifeforms.
F tossed the broken prosthetic to the floor and spoke.
"...I will take back the AC."
"Just try it, AI. You might have had the upper hand on the Internet, but..."
Crackle, crackle.
The electricity surging through my nerves burst forth in brilliant flashes of light.
"This is my domain."
Boom!
We kicked off the concrete floor and lunged at each other.
Clang!
Our prosthetics collided, sending blue sparks flying in every direction.
I couldn't afford to hold anything back.
Neural Acceleration
The electrical signals from the prosthetic arm hyper-activated every nerve in my body.
A rapid-fire barrage of strikes rained down on F like a snapping whip.
Thud, thud-thud, thud.
F's hands deflected my incoming punches with minimal effort.
He parried my onslaught with the absolute minimum movement required.
My thrusting fist merely grazed his cheek, and my sweeping kick only brushed against his collar.
If my limbs had been just one centimeter longer, those strikes would have landed.
He was calculating my attack range with absolute precision.
Following the trajectory of my retracting fist, F lunged forward, throwing his entire body weight into a tackle.
"Hup!"
Abandoning my guard, I tensed my chest muscles to absorb the impact.
After taking his blow head-on, I wrapped my arms around F, dragging him down to initiate a ground grapple.
Battles between prosthetic users rarely ended with simple strikes.
Against bare hands, you used a knife; against a knife, you used a gun.
The one with the superior weapon always won.
But when both sides were stripped of everything, wrestling was what decided the victor.
Specifically, tearing the opponent's prosthetic arm from their shoulder to seal away their Neural Acceleration.
That was the fundamental rule of combat between prosthetic users.
"Ngh...!"
Securing a leg lock from behind F, I wrenched his left arm backward.
If I could just rip his prosthetic out like this, the victory would be mine.
And yet...
"Heh... hehe...!"
His strength was monstrous.
Even though I was pulling with both of my arms, I couldn't overpower F's single left hand.
Click, click. I felt something snapping inside his arm.
"Tsk!"
Overpowered, I was flung backward and retreated to create some distance.
F slowly rose to his feet and reassumed his stance.
CC spoke.
He's releasing the human body's limiters.
"What does that mean?"
Humans subconsciously place limiters on themselves to prevent their bodies from breaking down. They only exert force within a safe range to avoid dislocating joints or tearing muscles. But because this isn't F's own body, he's pushing the joints to the absolute limit of their range of motion and overworking the muscles far past their breaking point.
"Can you do that too?"
I can't. The only thing I can control is your prosthetic arm.
...
Well, unless... you give me a spot in your neck-hub? Then it might be possible.
She was saying some terrifying things.
The neck-hub was a device directly linked to my brain. Having your neck-hub taken over was no different from having your entire body hijacked.
The Choi Kang-ho standing before me was the perfect example.
His body had been completely usurped by F through his neck-hub.
I mean, hey, I'm just saying it's technically possible.
Sensing the sudden chill in the air, CC quickly added the excuse.
Boom!
We clashed once more.
F's uppercut drove straight toward my solar plexus.
I raised my prosthetic to block it, but the sheer weight of the punch lifted the tips of my toes off the ground.
Wait, what?
F unleashed a relentless flurry of punches.
Thud! Clang! Crash! Bam!
Aaaaaaaah!
Every time F's fist slammed into my prosthetic, a message resembling a scream from CC flashed in my mind.
Though I was blocking every single blow, the impact kept launching me upward. Before I knew it, my feet were no longer touching the ground.
An aerial juggle combo?
Was this kind of attack even physically possible for a human?
The moment both of my feet were suspended in midair, he spoke.
"You cannot evade like this."
Zap! A brilliant blue light enveloped F's prosthetic arm.
It was a function that utilized electromagnetic fields to push the prosthetic's structural integrity to its absolute limit.
Instinctively, I disengaged the limiters on my own prosthetic, and a matching blue glow flared around my arm.
Clang!
A devastating blow, on a completely different level from anything before, slammed down onto my prosthetic.
I was sent flying, tumbling across the hard floor.
Only after rolling several times did I manage to catch my bearings.
A section of my prosthetic was caved in, perfectly matching the shape of his fist.
The skin around the connection port, already weakened by previous burns, tore open, spraying blood and fluid.
"Cough."
Even though I had blocked it, the shockwave was immense.
My internal organs vibrated violently, and the protein bar I had eaten earlier came spewing back up along with a rush of gastric acid.
"The power has depleted."
F said, looking down at his own prosthetic.
It seemed the battery stored in his prosthetic had run dry.
The same went for me. Neural Acceleration was never meant to be kept active throughout an entire fight. It was a temporary boost meant only for critical moments.
But when your opponent was charging at you with theirs active, turning yours off was tantamount to suicide.
"From here on, it is a battle of pure flesh."
F's right fingers were in tatters.
They were twisted at unnatural angles, with bone showing through the shredded flesh.
Yet, F didn't care about the damage to his physical vessel. He was fighting as if this battle were his absolute last.
Thud!
We collided once more in the center of the warehouse.
He continued to evade my strikes by the narrowest of margins.
Ah, if only your limbs were just one centimeter longer, you would have hit him, Mister.
I felt the exact same frustration.
If only my arm were just a little bit longer...
Wait, hold on.
There was a way.
"Haaah!"
I threw a left straight directly at his face.
F leaned his upper body back with fluid grace, dodging the strike.
It was an incredibly precise evasion, my knuckles barely brushing the tip of his nose.
Instead of pulling my arm back, I roared.
"Rocket Punch!"
Thump!
Propelled by electromagnetic repulsion, my left fist shot forward toward F's face.
Launched from a mere centimeter away.
It was an attack that could never be dodged.
If he were a normal human, that is.
Crack!
F's spine twisted at a grotesque, impossible angle, accompanied by the sickening sound of snapping bone.
The Rocket Punch sailed harmlessly through the empty air, flying past his head.
Springing back up like a coiled wire, F grabbed me by the collar.
Whoosh.
My feet left the ground, and I was slammed headfirst into the concrete.
Crash!
"Cough...!"
"Impressive. Launching your prosthetic arm using electromagnetic repulsion? You employ some fascinating techniques."
Through my fading vision, I saw F's body twitching in strange, erratic spasms.
Did he damage his nervous system by twisting his body so violently to dodge the Rocket Punch?
"But it was nothing more than a final struggle, human. Deprived of your prosthetic, you cannot defeat me."
Thud!
F delivered a brutal kick.
I quickly raised my right arm to block, but the force shattered my guard and buried itself deep into my solar plexus.
"Gah!"
"It seems that no matter how augmented your body is, your defensive capabilities do not match your offensive power."
Thud! Thud!
The kicks kept coming.
I rolled across the floor.
"Cough! Hack!"
"This battle was never equal from the start. I can release the physical limiters of this body. It means I possess a vessel one step more evolved than yours."
F stepped closer to deliver the finishing blow.
Spit.
Thick, dark blood spilled from my mouth.
Crawling away from F across the floor, I wheezed.
"You're right... This fight isn't equal. But then again, I've never cared about fighting fair."
"Your Shoeshine Unit always fought under disadvantageous conditions during the war," F remarked.
F continued.
"You never defeated me, not even once. Yet, strangely... I have no battles against you that I could evaluate as a true victory either. You always managed to survive somehow and appear on the next battlefield."
"Haha... To think there was still someone left in this world to reminisce about the battlefield with me."
It was absurd.
Ever since the day I lost my entire unit, I believed I was the only one left who remembered our war.
But to think I would end up sharing memories of those days with the very bastard I used to point my gun at.
"At some point, you all vanished, so I was never able to claim a final victory over you. But it seems we will finally bring things to a close today."
F spoke calmly.
"I pay my respects to you, who always struggled so fiercely against me."
F clenched his prosthetic fist.
He was going to end this.
Instead of crawling, I pushed off the ground and forced my body upright.
"Hey, AI. Want me to tell you why we never lost to you?"
F watched me, his fist still raised, showing a flicker of curiosity.
My legs, pushed far past their limits, trembled violently.
I stared straight into F's eyes and said:
"It's simple. Because we were never alone."
To us orphans, the Shoeshine Unit was our comrades, our friends, and our family.
On the battlefield, I had never once fought just to save my own skin.
And every single member of our unit felt the exact same way.
Hearing my words, F let out a hollow sigh, as if disappointed.
"Then this truly is the end. For you are alone now."
"No, you're wrong, AI."
Whoosh, whoosh, whoosh.
The sound of a heavy mass of iron slicing through the air echoed out.
"I am not alone."
I raised my right hand and caught the heavy iron object flying through the air.
It was Im Wonhee's prosthetic arm—the one F had snapped.
F's gaze traced the trajectory of the flying prosthetic back to its source.
CC.
My left arm, which had been launched by the Rocket Punch, had thrown Im Wonhee's prosthetic back to me.
I attached my old comrade's prosthetic, delivered to me by CC, to my left shoulder and activated its function.
Neural Acceleration
Zap!
Sparks erupted as the power stored in the prosthetic's battery stimulated my entire nervous system with a burning intensity.
Every reflex flared to life, moving as if possessed by a will of its own.
"Yoon Juhyuk—!"
F roared, throwing a punch.
Too slow.
I effortlessly deflected F's punch with my right arm and drove my left arm—my old friend's prosthetic—straight forward.
Thud.
Im Wonhee's prosthetic buried itself deep into F's solar plexus.
"Aaaaaaaah!"
Rush, rush, rush, rush, rush, rush.
Unable to react to the hyper-accelerated onslaught, F was utterly defenseless, taking every single punch directly with his body.
"Aaaaaaaah!"
As he began to fall, I launched him back up; as he was pushed back, I closed the distance; as he tried to counter, my fist struck first.
My barrage did not stop until the very moment the battery completely ran dry.
And then, finally—
Thud.
F collapsed.