"Uwaaaaaah…"

Left, then right. A brief moment of grinding its head against the wall, then left again.

A charging pattern where it repeatedly slammed its skull into the walls as it rushed forward.

I yanked James’s arm.

“Ugh!”

We veered sharply left at the cross-section just as a deafening crash echoed from behind.

If only that were the end of it.

“D-Did it die?”

One slam.

Then another.

Backing away, I aimed my shotgun toward the hallway.

"AAAAAGH!!!"

Clang!

Steel plates crashed down as a burning mass stumbled into view.

Its face, a grotesquely mutated wreck—jagged, oversized teeth clicking together as it heaved for breath, flames devouring its fur.

Boom. Boom.

I worked the pump, squeezing the trigger without hesitation.

But the massive creature kept coming.

"Just die already!!!"

Click.

The bolt locked back.

The corridor flooded with orange flashes as a fresh storm of bullets burst forth.

The ejected shells clattered against the floor, glowing hot from the barrage.

"Grhhhk! Guhhh—AAARGH!!!"

Its eyes were already gone, its teeth shattered by gunfire.

Yet it pressed forward, swiping blindly.

One arm shielding its face.

The other slamming against the ground for momentum.

But with that stance—its injured leg was exposed.

“Go for the legs!”

The empty magazine dropped to the floor, a fresh one snapping into place.

The bolt catch released with a metallic clang.

"AAAGH!!!"

Rounds ripped through flesh and bone.

The loose tendons barely holding its leg together finally snapped.

It let out a guttural scream as it crashed down.

Boom. Boom. Boom. Boom.

The shotgun blasted away at its twitching limbs, while the rifle—its barrel glowing red-hot—continued vomiting rounds into its body.

Its giant hand finally hit the ground, lifeless.

Even as its tongue, bitten off in its death throes, lolled from its ruined jaw.

Clink, clink, clinkclinkclink…

A cascade of spent casings poured onto the floor.

The air was thick with the stench of blood.

And gunpowder.

Until the great ape’s face was nothing but a mess of pulp.

"Haa… haa…"

"...Huff… huff."

In the dim corridor, the red-hot barrels of our weapons cast a faint glow.

Smoke curled from the chamber of my shotgun.

“Koff, koff!”

In the game, it was just a matter of clicking a mouse.

Yet here—even after seeing it fall, I could barely believe it.

The massive corpse continued to burn before us.

“…How many more of these damn things are there?”

“There are worse ones.”

James, slumped against the wall, muttered in disbelief.

I answered, and his already vacant expression darkened further.

He couldn’t afford to fall into shock.

The noise and fire would attract unwanted attention.

I pulled out a cigarette, offering him one as well.

Lighting mine, I leaned in to ignite his trembling fingers.

“Hoo…”

"Huuuu…"

The first cigarette had tasted like hell.

But now—I was starting to get used to it.

The faint, sweet bitterness left on my tongue.

The white haze settling my racing heart.

"I thought you'd be guarding your daughter."

“…Sarah, right. Damn it, Sarah!"

“Something happened?”

James nearly choked on his cigarette, scrambling to his feet.

"Her allergic reaction got worse. She’s breathing, but… she’s in pain."

"Ah, shit."

"Did you find any more meds? Any medical rooms?"

"No medical rooms… but—"

The corpses of the cultists.

They had to be carrying something.

"Come with me."

Since Newskins had high regeneration, Rebirth cultists never wore armor.

Instead, they carried bullets, gun modifications, and—more importantly—medical supplies for trade.

And valuables.

“Here.”

The problem?

The state of their corpses.

"Check their pockets."

No point in searching the ones Hammerhead turned into paste.

The ones I needed were the bodies tossed aside—the ones flung against the walls, their necks snapped.

"Ughh, fuck…"

In the game, corpses were just background assets.

Only execution animations had any detail.

Here?

Shattered bones. Bent limbs. Faces twisted in agony.

My vision swam.

"Hooooo…”

The cigarette helped.

Without it, I might’ve done more than just grimace at the sight.

Without the buff, my weakened mental state could’ve easily tipped into retching.

I reached into the blood-soaked inner pockets.

The warmth of fresh liquid clung to my fingertips.

The cloudy, lifeless eyes—it felt like they could start moving at any moment.

“Ugh…”

I forced myself to ignore it and continued my search.

And then—

“Ah.”

Found it.

A syringe with an orange tip.

But—

“Did you find something?”

“I found a stimulant.”

“…She already had one injection.”

“Another one?”

“It’s been… what, ten, twenty minutes? Her allergic reaction came back, so we had to use my dose too. Even after that, she started seizing again.”

If a stimulant was used too frequently, its effectiveness diminished.

A third injection would count as substance abuse.

And if she was already addicted, stacking overdose penalties on top of that meant a high chance of death.

“Damn it, this is all we—”

“Wait, did you find anything else?”

"Nothing but this weird pile of pills."

An ‘Unsorted Meds’ item, straight out of the game.

In the system, it could be combined with other syringes to create healing boosters, painkillers, anti-bleeding agents… all sorts of effects.

And if mixed with a stimulant, I could make an antidote.

If I could craft it.

"We don’t have time, just give me that—"

"No, wait."

I dumped my bag out.

The Improvised Crafting Kit hit the floor with a dull thud.

And then—

Something was different.

Last time, I was sure the button was locked shut.

But now—

Shhk.

‘It’s… open.’

Had I just roughly jostled my bag and accidentally loosened the latch?

Or did this world really function like a game, unlocking it once I fulfilled the requirements?

"Damn it, my daughter is dying!"

"And you know damn well another stimulant will kill her."

“What the hell are you even doing with those mystery drugs—?!”

To be fair, his reaction was completely normal.

Blindly injecting unknown substances could cause uncontrollable side effects.

"Wait, what are you doing to that stimulant—?!"

"Stay put, I want to save Sarah just as much as you do."

Because this was Concrete Under.

Because, in the end—this was a game.

And now, I had the kit.

‘…Antidote.’

Two handfuls of pills. One stimulant.

As soon as I thought it, faint holographic outlines appeared on the black cloth.

Just like in the game, I placed the ingredients on the crafting mat.

Click, click.

My hands moved on their own, peeling open the pill packets and dropping them onto the cloth.

A small mortar and pestle—where had that come from?

I wasn’t even surprised anymore.

My hands knew what to do.

The tools hadn’t been there a second ago, but now they were in my grasp, grinding the pills into powder.

“…”

I retrieved tweezers, carefully detaching the needle’s reservoir.

If I mishandled the mechanism, the syringe could accidentally discharge.

Carefully—carefully.

I separated the chamber, pouring the powder inside.

Finally, I reassembled it in reverse order.

And when I was done—

"Give this to your daughter."

“…”

"It’s an antidote."

“But—"

“Hurry! If it fails, you can shoot me.”

I snapped the kit shut, pressing the button firmly closed.

Slinging my bag over my shoulder, I stood up.

James's expression remained stone-cold.

"...Or give it to me and I'll inject her in front of Curtis."

“…You’re telling me, you made an antidote by mixing pills into a stimulant?”

Realistically? Completely absurd.

But if a Crafter could cobble together a functional shotgun out of scrap metal, then—

"She went into respiratory distress over five minutes ago."

I loaded my shotgun.

"If you give her another stimulant, she’s going to die. If we do nothing, she’s going to die. If her allergy is this severe, she won’t survive without an antidote."

“…”

"So at the very least—we can try what I made."

James clenched his teeth.

“…Let’s go.”

We sprinted past the smoldering corpse and its crushed helmet, down the long corridor.

A dim glow flickered from a room ahead.

A faint voice murmured inside.

“Oh, my poor granddaughter… Sarah…”

Crossing the threshold, I rushed toward Sarah, her face pale and ashen.

Curtis didn’t even have time to react.

I jammed the antidote into her thigh.

If this world truly followed the game’s mechanics, then no matter how ridiculous it was to mix powder into a stimulant, it would work.

“Ghhk… ugh…”

Sarah’s leg began to tremble violently.

The wound swelled even redder, pulsing angrily.

"What the hell did you do to my granddaughter?!"

“Ghk—!”

The barrel of a rifle pressed firmly against my temple.

“I swear, if anything happens to Sarah—”

A double-barrel shotgun touched my jaw—the cold steel sapping the heat from my skin.

Click.

The hammer was cocked.

The buckshot was ready to shatter my skull at the slightest pull of the trigger.

As expected, James hadn’t even bothered switching his rifle’s safety off.

A single twitch of his finger, and my brains would be decorating the floor.

But—

Splurt, splurt.

A yellowish fluid spurted from Sarah’s wound.

And almost immediately, the swelling began to subside.

Sarah, who had been thrashing in agony, suddenly took a deep breath.

Then, her body relaxed.

“Sarah?”

Just moments ago, she had been gasping, choking for air.

Now, only calm, steady breathing remained.

"Squeeze the rest of the venom out."

I lowered my head slightly—just enough to lean away from the barrels.

The triggers weren’t pulled.

The hammer on Curtis’s shotgun slowly eased back.

Beside me, I heard the click of James flicking his rifle’s safety on.

“…We need to move. The poison’s gone, but if the wound gets infected, that’ll be a whole new problem."

Forcing my unsteady breath to calm, I grabbed a lantern from the wall.

Curtis finally lowered his shotgun.

Still shaking, he grasped Sarah’s hand tightly.

James… couldn't even look me in the eye.

He simply stared at the ground.

"There should be a clean room nearby, we’ll use the closest one as a temporary shelter."

As I carefully lifted Sarah onto my back, Curtis wordlessly adjusted her arms and legs over my shoulders.

James stepped outside first, waiting silently for me to follow.

“Hey, about earlier—”

"We’ll talk later."

The first priority was finding a sterile room.

We needed clean bandages to prevent infection.

A Crafter didn’t survive through charisma alone.

They survived by proving their worth.

"Alright, let’s move. Lead the way—we need to get her to the medical bay."

At that moment, everything clicked into place.

This was Concrete Under.

The game I had spent over 2,000 hours playing.

And now that the tutorial was finally over—

The first step was establishing a base.