I thought I was late because I’d been on my phone, but it turned out Yun had just come out a little earlier than expected.

But what are we doing starting today? Is it going to be like last time, where I just get beaten up?

I worried, but things unfolded in a more reasonable way.

First, we warmed up and ran. Starting from the cabin, we made a long loop and came back. Everything was where it should be, neatly arranged along the street. The city baked under the warm sunlight, and Yun and I kept silence while we ran.

After returning, we walked about ten minutes to a gym and did strength training. The gym was wide and filled with well-maintained, modern equipment—yet there wasn’t a single person there.

That was so strange I couldn’t help but ask.

“Why is there not a single person here?”

“Because this gym belongs to me.”

Crazy.

“When I’m busy, come train on your own. I’ll register your fingerprint.”

This man was seriously rich.

I had guessed it when I saw his car, but I hadn’t known it was to this extent.

Anyway, we trained there. Yun seemed to be testing my abilities, making me do balanced workouts—lower body, upper body, flexibility exercises, all of it.

Strangely, my body wouldn’t follow.

It had been the same while running earlier. I felt like I should have been able to run farther, faster, but my body couldn’t keep up. The same with weights and sets during strength training. My ankle flexibility seemed worse too. When I tried juggling, my dynamic vision had clearly deteriorated.

How did I end up like this...

Like this?

“Were you a trainer?”

I straightened my back.

“Pardon?”

“Even if you’re not good, your form is that of someone who’s been at it for years.”

Yun squinted and studied me.

With his hands shoved into the pockets of his black windbreaker, he frowned slightly.

“It looks like you took a break for a few months, but whatever I make you do, your form is perfect. You hit the muscle stimulus points properly too.”

“Is that so? That’s a relief. I was just thinking myself that my body wasn’t keeping up... so I must have taken a break for a few months.”

“You don’t remember training?”

Not really.

Whenever Yun made me do something, I simply remembered how to do it. Deadlifts, bench press, push-ups, pull-ups—it all came automatically.

When I told him this, Yun fell silent, deep in thought.

Then he said,

“When the mushroom hit you, you instinctively used a breakfall.”

Did I?

“How much do you plan to build your muscles?”

“I don’t want to build them too excessively. That would reduce flexibility, increase injuries, and restrict movement.”

“See.”

Yun spoke.

“You’re not the type who worked out as a hobby. You either did it for a living, or you were in the military or police, or maybe a stuntman.”

Was I?

I still remembered nothing.

But Yun didn’t press me for an answer. Instead, after finishing strength training, he dragged my exhausted body down into the shooting range.

The shooting range was under the gym.

Just how rich was this man?

“I take back what I said about you maybe being military or police.”

The moment I finished shooting, Yun gave that evaluation.

“You’re good at working out, but why are you so bad at shooting?”

Sorry, sir.

Yun made me practice shooting all afternoon. He didn’t seem to care about wasting ammo, letting me fire live rounds to my heart’s content. When I was completely drained, he dragged me away to his house.

To be precise, into the spacious underground laboratory beneath his house.

A cool place smelling faintly of disinfectant.

There, he showed me a “mini core” model.

A dome-shaped glass shield covered a model city, like a snow globe cut in half.

“It’s made of the exact same material as the Breath protecting the Center Core.”

“Breath?”

“The original name of the barrier is Breath. Most people just call it a Core. But strictly speaking, the Core is the entire area encased by the barrier. The barrier itself is called Breath.”

“I see.”

“John Mühlen invented it. I commercialized it.”

“...What?”

My voice cracked in shock. I turned wide eyes on the man beside me.

“That’s an incredible achievement, isn’t it?”

“Technically, yes.”

He was not a modest man.

But now I understood why he was so rich. It must have been patented. Anyone who commercialized a device essential to humanity’s survival would, of course, be wealthy.

Yun looked down at the toy-like mini core, pressed something on its base.

A small opening appeared in the dome’s lower rim. Arched, like a tiny doorway for little folk.

He pointed at the hole with his finger.

“When you go outside the Core, you make a door like this.”

“You go outside?”

Why would anyone go outside? The Breath was there to protect the city from grotesque mushrooms and spider-like creatures.

His dry voice answered.

“Ordinary civilians don’t. We do.”

His low voice explained.

“We have to take back the land we lost.”

A strange feeling washed over me.

I couldn’t name it, couldn’t understand why. Only that his flat explanation had triggered it.

A fleeting afterimage crossed my mind. A forgotten memory flashing up and vanishing. Too quick to grasp.

I stared intently at my mentor.

“What’s out there?”

The answer came lazily.

“Creatures.”

So that meant, after I gained enough seniority, I’d be sent outside the Core. Since the outside must be dangerous.

“You only get inside the Core once you have enough seniority.”

Excuse me?

“The Core is full of civilians.”

Well... that was true.

Yun turned on the screen fixed to the laboratory wall.

Like a surveillance system, the display split into multiple panels. Strange things began to appear on the screens. In some backgrounds, bluish-green plains. In others, barren gray wastelands like an apocalypse film.

Like stages changing in a game, the backgrounds flicked past, filled with wandering creatures.

No trace of human life anywhere.

So this was outside the Core.

“Near the Core is relatively safe. The Badgers clear the area. The farther away you go, the more dangerous it gets. Some zones even cause drones to vanish for unknown reasons. We classify areas by risk. But watching it on a screen doesn’t give you a real sense, does it?”

A bad feeling crept {N•o•v•e•l•i•g•h•t} over me.

So I replied politely, quickly:

“The video quality is excellent. It feels as vivid as reality.”

“Explaining with words doesn’t make it stick.”

He wasn’t listening.

Yun kept pressing the keyboard, changing footage. The screens flicked past, and I grew more and more overwhelmed.

What were those bizarre things?

Yun paid no attention to my expression, continuing his explanation.

“If creature danger is ranked from 1 to 10, then outside zones are classified from A to F. A is the furthest Badgers can go. F is where new recruits start.”

“I see. Then that upper-right screen, with all those creatures swarming— is that Zone A?”

“That’s Zone S. Off-limits.”

“...Huh?”

Wasn’t A the last zone?

Without looking away from the screen, Yun explained.

“There are areas even skilled Badgers must not enter. We group those together and call them Zone S.”

“Then how did you film that?”

“Drones.”

Ah.

“Well, it’s a relief it’s Zone S. I probably won’t have to deal with it.”

“Zone S will someday be turned into Zone F and brought inside the Core. That’s why we go outside.”

“...Then I’ll correct myself: that’s a story for the very distant future, thankfully.”

“In a week, we’ll go outside.”

I knew it!

The moment he said “words don’t make it stick,” I’d had a bad feeling.

This man... ever since that mushroom creature, I’d suspected it—he definitely believed in learning by throwing yourself headlong into it.

Yun saw my twitching lips and raised an eyebrow.

“Why that face?”

“Do you really not know?”

“No.”

Human being.

He shut off the screen.

Every one of his movements radiated efficiency. No wasted motion.

He pulled a tablet out from under the desk.

“Let’s build up your stamina over this week.”

“Is that possible in just one week?”

“You’re not in that bad shape now.”

Really?

I couldn’t hide the relief in my voice.

“Good. I was worried...”

“You’re still far from ready to be deployed, though.”

He gives the disease and the cure.

Once again, Yun ignored my reaction.

He swiped through the tablet, outlining my one-week training schedule.

Eat breakfast, train from 9 a.m., lunch, rest, train again at 2 p.m., finish by 6 p.m. After that, study the world online. Ask questions via messenger whenever I want.

It was more manageable than I had expected. Ending at six and being allowed internet access was good.

Thinking about introducing myself after a week made my stomach twist, but the week itself looked surprisingly okay. My spirits lifted.

“Considering your situation, they’ll advance you one month’s salary. Use that to get by.”

Before I left his house, Yun handed me a card.

I accepted it with a relieved face.

“Thank you.”

Having usable money eased my mind. I’d check the ATM, then buy clothes, food, and basic supplies. Now I had a place to stay and work too.

Ah.

I’d been worrying constantly, but it felt like everything was turning out well—

KWAANG!

“What the hell?!”

“What else? A creature.”

Yun swatted away a dog-sized creature that had leapt at my face—using his phone.

The thing crashed to the ground along with the shattered screen.

A phone isn’t a ping-pong paddle. I stared blankly at the twitching beast on the ground, dumbfounded, as Yun strolled over lazily.

He bent down to check the creature.

“Strange. I lured it toward me, but why did it jump at you?”

It resembled a whale.

Actually, it was practically a whale.

CRUNCH!

Yun crushed it underfoot.

A shame.

That thought flashed across my mind.

...Huh?

“Why did I think it was a shame?”

“What?”

I muttered, confused at myself, and Yun straightened up.

“It’s nothing. But... do these things really respond to lures?”

“Yeah. They move according to frequencies humans can’t hear. The creature alarms have been going off, getting closer, so I played a sound from my phone to draw one in.”

He arched his brows.

Then narrowed his eyes at me.

“Why did it go for you?”

“Obviously because I look easier to handle.”

If I were that thing, I wouldn’t have gone after Yun either.

Though I hadn’t known him long, Yun already struck me as someone with unnervingly minimal movements, oppressive aura, impossible to read.

“We weren’t even that far apart, though.”

Oddly, Yun didn’t seem convinced by my answer.

He said nothing, but his gaze lingered on me.

Finally, he dismissed me back to the cabin, saying the cleanup team would collect the corpse.

I nodded and left.

On the way back, I kept feeling it—a sense of regret I couldn’t explain.

Not even the one thinking it could accept the thought.

But it was regret all the same.

That had been a fine specimen.