A Blueprint for Survival
Before heading downstairs with Yeo Ildu, the foreman, we sat facing each other on the 10th-floor floor.
I drew a simple sketch in the dust on the concrete with my finger.
Our movement route for today.
“The basic route is to go down through the stairwell, check each floor’s corridor, and come back up. We can pick up the materials on the way back.”
Yeo Ildu followed the line I had drawn with my finger without a word, then nodded.
“How should we split the roles?”
“You take the front. Since you see better and spot blind spots faster, stand in front. I’ll handle the rear, controlling the noise while gathering the materials I bring up. I’ll cover the back.”
“Good.”
We immediately descended to the ninth floor.
The moment we arrived, I pulled a white reflective tape from my pocket and stuck it small on the floor where the stairwell connected to the corridor.
A mark that could be identified even in the dark just by the feel of the toes.
We installed the first trap in an area outside the predetermined route.
Yeo Ildu pulled long wires from his tool pouch and stretched them tautly between protruding rebar on both walls.
The first line was at a height level with an adult man’s Adam’s apple.
It was a spot where an infected, running from the dark without being seen, would trip and fall straight without ever noticing it.
I flicked the wire with my hand to check the tension.
This wasn’t one that would stop you if you hit it; it was a height that would let your neck snag and make you topple backward without slowing down.
I also tied another line at ankle height right below.
Go over the top and the bottom catches you; look down to avoid the bottom and the top hits your neck.
On the eighth floor we installed a different kind of trap.
I chose one of the scaffolding planks lying in the corridor and loosened the clamp just enough.
Not fully removed, just enough so the bolt was barely in place.
It looked perfectly secure from the outside.
But the moment someone stepped on it and weight came down—
CRACK!
One side of the plank would tilt and let out a loud metallic clatter.
It would serve as an alarm that alerted intruders to the sound and vibration.
And if an infected charging full speed stepped on it, it could become a trap where the plank might just give way.
I made a few simple snares out of the remaining wire.
Structures that tightened on their own when you stuck your foot through them and hung them on doorframes or handrail posts.
Yeo Ildu looked at them and muttered,
“Don’t space them too tightly. If we get confused, our ankles will get caught first.”
Traps were dangerous not just for the enemy but equally so for us allies.
As we descended, we decided on the priority order of the materials we needed.
First, usable scrap wood for fuel.
I had already selected some reasonably long lumber or plywood, and I would check the grain once before we used them so we didn’t waste precious resources on burning.
Second, waterproof tarps for windbreaks.
Most of the blue tarps rolling around on-site had torn corners, so I needed to choose the ones with intact attachment rings.
Third, ropes or slings for carrying materials.
Originally meant to lift equipment by hooking to the ceiling anchors, but now they were the lifeline for hoisting things up to the tenth floor.
Fourth, clean containers to hold water.
And last, steel drums for making campfires or heating water.
Yeo Ildu would confirm the rear with hand signals every time we rounded a corner.
I would follow behind and gather usable materials to one side.
The corridor was already cluttered from construction days, so there was no need to worry about extra mess or dirt.
Even a small amount of noise could attract the infected’s attention.
So we carried the lumber piles quietly.
I stepped only with the balls of my feet instead of my heels and chose planks that wouldn’t let me step on loose plasterboard pieces.
Every time we finished clearing one floor, Yeo Ildu would stand on the landing and listen for sounds from the lower levels.
Concrete stairwells amplified noise, so even the slightest metallic scrape would give us away immediately.
While he checked, I would tie the gathered materials with rope.
It was a safety rope originally meant to prevent falls, so my hands were already used to the feel of it.
Our hands moved in perfect sync without a single word.
What should have taken a full day alone was finished in less than half a day.
We had installed the traps on the ninth and eighth floors and were now heading into serious search mode starting from the seventh.
We set a rule: stop briefly at the flat spot midway on every floor’s stairs.
I would check first for any sounds coming up from below.
Metallic clangs from the steel railing, footsteps of someone walking through dust, and any dragging or scraping sounds from somewhere.
If nothing came through, Yeo Ildu would signal to proceed with a hand gesture.
Ninth floor—no issues.
Eighth floor—no usable materials.
Seventh floor—quiet.
Sixth floor—lots of dust and trash.
Fifth floor—only wind noise.
Fourth floor—some interior materials needed for work had been stacked.
It was when we had descended all the way to the third floor.
Near the hospital room where I had found Yeo Ildu yesterday.
Faint sounds reached us.
Grrrr—
We quickly hid behind the lumber piles again.
From the corridor on the other side, a small-framed infected wandered around.
Smaller in size and slower in movement compared to the others.
But because of that small body, it might actually be more dangerous.
It was easy to miss in the line of sight and hard to find if it hid between the material piles.
‘...Should I kill it?’
If I rushed in carelessly and the noise drew more, they would all come running.
Yeo Ildu pointed toward the opposite side with his fingers, indicating he wanted me to lure it there instead of confronting head-on.
I nodded.
Yeo Ildu tossed a small pebble from the end of the opposite corridor, making a sound.
Tap—
While the infected’s gaze turned that way, I approached silently from behind.
I grabbed the collar of its shirt briefly at the nape of the neck and tied a small bell I had prepared in advance.
A steel bell hanging from a fishing line.
I pulled my body back just before it started thrashing.
Clang—
The infected tilted its head and stood still.
Now, wherever that thing was, we could track its location just by the sound.
I retreated to the stairs one floor up, confirmed the bell sound hadn’t followed, and only then let out a long breath.
Outside the window, movement could be seen.
Some of the infected that had been wandering outside the site in response to the bell sound began approaching the fence.
They glanced inside the building briefly, then, seeing that the bell owner was one of their own, soon lost interest and scattered.
I counted the numbers on the window frame with my fingers.
‘Twelve of them... but a few got away. Now only about five are left?’
Now, even if I only heard a clanging sound from somewhere in the corridor, I could roughly guess the position of the one on the third floor.
Where had the rest gone?
Were they hunting farther away, or were they looking for other survivors?
What was certain was that as long as those guys were guarding the outside, we couldn’t leave.
The entrance was blocked by a crumpled car body and collapsed fence.
Even the smallest sound would make them react instantly.
Leaving would mean making noise and becoming a target for them.
We finished the search on the first floor.
As we descended, familiar traces appeared here and there.
A toolbox lying face-down at a corridor corner.
A hard hat rolling around at the landing as if someone had tripped while running.
A long smear of half-dried blood on the wall.
It felt like their paths were drawn from where they had fled until they were caught.
On the third floor, only the one we had attached the bell to remained.
Inside the building, no one else was left except that single infected.
On the first-floor floor, a pair of discarded work gloves and a safety shoe lay scattered.
I picked up the glove for a moment.
The familiar feel of worn leather.
The gloves I had worn and taken off without thinking on the way to work, but now I had no idea where their owner was.
I silently put the glove back in its original place.
We began carrying the materials we had secured up to the tenth floor.
Scrap steel drums, tarps, ropes, water jugs, and scrap wood for fuel.
The quantity was quite a lot.
Hoisting them with ropes tied around was delicate work.
If the weight shifted to one side, the scaffolding pipe might twist, or the rope could slip off a corner and snap.
Things that easily scraped edges, like steel drums, I wrapped once with tarp before hoisting them up.
Spreading the friction with cloth extended the rope’s lifespan just a little.
Yeo Ildu pulled from above and I pushed from below.
Sweat poured down like rain, but we couldn’t stop.
Once we had moved every material to the tenth floor, dusk began to fall.
We immediately started reinforcing our base.
In the center of the tenth floor, I stood a scrap steel drum and placed wire mesh on top.
Between the floor and the drum, I laid down lumber to create an air gap.
That way, air could flow underneath and the fire wouldn’t be smothered.
Next to it, I filled a clean paint bucket with water from the lower floor.
The small holes that were originally there on the drum remained as they were.
When we lit the fire, I positioned it so that smoke and heat would exit through those holes and flow toward the scaffolding, taking into account the wind direction.
A ready hearth where we could heat water anytime we wanted just by making a fire.
In just one day, the tenth floor was turning into a livable space.
* * *
When evening came, the outside was once again swallowed by darkness.
From a distance came intermittent car collision sounds and short screams.
The sounds repeated, coming closer then fading away.
People were still desperately fighting for survival in that distant place.
The air inside the tenth floor was different from outside.
A small campfire burning inside the steel drum was giving off warmth.
The subtle twisting sound as the metal plate heated up, and the heavy heat rising from the steel, warming my thighs and the backs of my hands one by one.
We placed a copel on the wire mesh and boiled instant ramen.
While the water came to a boil, I checked the ceiling top and the scaffolding area in turn to make sure the smoke wasn’t leaking too much.
Right now the wind was blowing strongly, so the smoke was being sucked out easily, but we would have to think again if the direction changed.
The first hot broth in days.
The moment it went down my throat, the frozen joints in my veins slowly loosened, and the stiff muscles that had hardened found their places again.
‘It’s delicious.’
After eating, I heated the water in the jug beside the drum.
I dipped a cloth in the steaming hot water and wiped my body.
Starting from my face, neck, armpits, and waist, as if peeling off a layer of dust and sweat.
The remaining water I poured into a small paint bucket and soaked my feet in it.
As the hot water soaked the calf and thigh muscles that had been sore all day from climbing and descending stairs, I felt blood begin to circulate again.
I spread my wet work clothes by the fire to dry and sat down to sharpen the rebar window end once more.
Just then—
Shick—
A short sound of something metal sliding came from the upper floor.
Both my and Yeo Ildu’s movements stopped at the same time.
A brief silence.
Then another sound followed, something being dragged along the floor.
‘...What is it?’
No one was above the tenth floor.
We silently exchanged glances.
He picked up his hand trowel; I grabbed the rebar window.
The reason I had sharpened this window edge to a point was simple.
To maintain distance and stab at the vital point in one go.
We silently divided roles.
Yeo Ildu went toward the stairwell; I headed toward the scaffolding.
We slowly ascended the eleventh floor while narrowing the encirclement.
In the center of the eleventh-floor corridor, a man stood swaying.
He wore a tower crane operator’s overalls.
Park Jaedong.
I blocked his retreat from the window side while Yeo Ildu approached from the stairwell.
Upon seeing us, he jumped back in surprise.
I spoke first.
“Show your hands. Slowly.”
Yeo Ildu added,
“Neck and wrists. Roll up the sleeves too.”
Park Jaedong obediently raised both hands.
“P-please save me. W-water, please. I haven’t had even a sip of water since yesterday.”
His voice was cracked.
Yeo Ildu and I quickly scanned around his arms and neck.
No bite marks were visible.
His breathing was rough, but the words flowed clearly.
It was most likely just dehydration.
We took him downstairs to the tenth floor.
After drinking water, he let out a long breath before finally speaking.
“Thank you. The situation downstairs was too terrifying, so I held on in the crane cabin... I couldn’t hold out any longer and came down. I’m really glad you two are safe too like this.”
Park Jaedong looked at us with a tired face.
In his eyes, relief lingered together with a tremor that hadn’t vanished yet.
I patted the crane operator with a friendly face.
“You’ve worked hard so far. Today, eat dinner and rest well. Tomorrow will be busy.”
Park Jaedong looked at me with an expression of incomprehension.
“Huh?”
Yeo Ildu, having understood my intent, reassured Park Jaedong.
“Don’t worry. Rest well today.”
No-gangje technology to survive the apocalypse