Chapter 1 - Companion I

Infinite regression.

There is a genre by that name.

“Infinite regression” refers to stories in which the protagonist, upon dying, returns to a point before their death and keeps tackling the challenges ahead.

Naturally, no matter how daunting those challenges are, the protagonist somehow overcomes them. After all, they only need to keep trying until they succeed.

A fate destined for a bad ending turns into a happy one, or the protagonist miraculously saves a secondary heroine who should have died of an incurable disease—

Infinite regression is practically a cheat code that puts an end to every tragedy.

But as someone who has experienced it firsthand, let me tell you: the infinite regression portrayed in all those novels is nothing but cheap propaganda.

Like a cram school that hangs banners listing only the students who got into prestigious universities.

“Fuck. This isn't going to work, is it?”

I set down my sword cane.

Regression number 1,183.

The world had ended again. Winners win. Losers lose. I belonged to the latter category. At last, I had no choice but to admit that no matter how desperately I struggled, I couldn't stop the world from ending.

This is not a story of success, but of failure.

It is merely the aftermath of someone who, despite possessing the ability to regress infinitely, ultimately failed to prevent the apocalypse on his own and finally let go of himself.

2

The first thing to bear in mind is that human mental resilience—our strength of mind—always has an expiration date.

No matter how fine someone looks on the outside, as regressions repeat, something unseen will inevitably break.

Old man Schopenhauer, whom I'm about to tell you about, was a prime example.

“A direct ancestor of mine was a very famous philosopher.”

“Old Man Scho” often bragged about his pedigree.

I'd certainly heard the name Schopenhauer-whatever before. But honestly, unlike his esteemed ancestor, Old Man Scho was about as far from philosophy as a man could get.

“What do you call those muscles? Get some exercise, would you? Exercise!”

Though he was sixty years old, his entire body was packed with muscle.

More at home pumping iron than pondering ideas, Old Man Scho was always preaching the importance of exercise.

“But all those muscles disappear when you regress anyway...”

“Weight training is a habit. Habits don't disappear.”

Old Man Scho spoke solemnly.

These days, I have an ability that preserves my muscles and internal energy even when I return to the past—the skill known as [Continue]. Back then, though, I was still a greenhorn with only about ten regressions under my belt. So it was very hard to sympathize with Old Man Scho's philosophy.

Nationality, generation, tastes, beliefs, political leanings—Old Man Scho and I were opposites in every respect. We didn't have a damn thing in common.

Even so, there was exactly one reason we always stuck together.

“Tsk. This run's a lost cause, too.”

“Looks like it.”

Infinite regression.

That's right. Old Man Scho and I were regressors with the same ability.

For some reason, the world I lived in had not one regressor, but two. Considering that most fiction grants infinite regression to only one person, this was quite unusual.

“Bah, it's hopeless. Hopeless. We can't kill that monster.”

“What should we do, then?”

“I'll go first. You come along later. Run while I hold it off, and keep fighting to the bitter end. Then perhaps we'll see a way through on the next run, eh?”

“Fuck. You always leave the hard part to me, old man...”

“Now, now! What's this ‘fuck’ business? Respect your elders, you brat!”

Old Man Scho, who invoked the Korean maxim about respecting one's elders with flawless Korean pronunciation, was, absurdly enough, German.

I first met him on my sixth regression. At the time, about the only Korean he knew was a clumsy “hello.”

But as soon as he learned there was another infinite regressor just like him, Old Man Scho threw himself into studying Korean.

The seventh run, the eighth—as the regressions went on, his Korean improved by leaps and bounds. By the tenth, he spoke it better than I did.

So well, in fact, that he read [The Analects] in Korean rather than German.

“Your enthusiasm really is something, old man.”

“You brat! It's habit, not enthusiasm! I learned because you wouldn't learn German! Good grief. You've even acquired perfect recall, so why on earth won't you study? As they say, ‘Is it not a pleasure to learn and practice what one has learned?’ How can someone so much younger than me find learning such a chore? Honestly! Tsk, tsk...”

“...”

Perhaps he'd learned a little too well.

Anyway, thanks to Old Man Scho installing Korean in his brain along with the ability to nag like a Korean old-timer, communicating became dramatically easier.

After all, we had two infinite regressors, when even one was a cheat code.

Sometimes I sacrificed myself, and sometimes Old Man Scho did. Little by little, we wrote a walkthrough for this world.

“We did it! We actually did it!”

We both cheered when we defeated “Tenlegs,” a monster no one had managed to beat for ten whole runs.

After blowing off that loathsome mop-tentacled head, Old Man Scho even threw aside his sword and flung himself at me.

“Oh, Doctor! Thank you! It's all thanks to you! I'd never have made it this far alone!”

He laughed like a little boy.

The truth was, although we'd worked together from the sixth run through the tenth, some part of us had remained wary of each other. Trusting someone was hard in a world on the brink of destruction.

Both Old Man Scho and I had seen too much to trust anyone easily.

But the moment this white-haired German geezer beamed and hugged me, I felt that last trace of wariness between us melt away without a trace.

I looked into his gray eyes. I could tell he felt exactly the same.

Yes. We were pilots who had crash-landed at the end of the world. Though we couldn't claim to have been born on the same soil, we were comrades who had jumped with flimsy parachutes spread, aiming for the same landing point.

After that day, many things ceased to matter between us. Nationality, generation, tastes, beliefs, political leanings—all lost their inherent gravity.

In that atmosphere of weakened gravity, we became lighter.

“Truth be told, this regression business is very hard to get used to.”

Old Man Scho freely revealed his human side to me—the parts that, in a ruined world, were called “weaknesses.”

In the mornings, we'd fill a thermos with coffee, or take a whole bottle of soju, and head to an empty café for a quiet chat. (With the world having ended, there were plenty of cafés whose baristas had fled.)

“Why?”

“When we regress, we wake up on June 17, don't we? Well, one minute after the regression begins, my wife dies.”

“What?”

This was what he told me.

June 17, 13:59. That was the point at which our regressions began. Unfortunately, around 14:00 on June 17, a gate opened in Seoul, South Korea, and everything south of the Han River vanished at once.

Unlike the two of us, who escaped the disaster because we were in Busan that day, Old Man Scho's wife was attending an academic conference in Seoul.

“One minute. Just one minute.”

Old Man Scho swallowed a mouthful of soju.

“My wife is running the event in the auditorium at that time. A number of famous scientists are gathered there.”

“Even if you warn her that a gate is going to open... she can't get away.”

“That's right.”

It was a catastrophe that devastated all of Seoul at once. Even if Old Man Scho called the instant he regressed and told her to evacuate immediately, escaping the tragedy was physically impossible.

“Even when I call, she doesn't pick up straightaway. She puts her phone on silent during important events... She only answers after I call three times in a row.”

“...”

“By then, there's no time left. I barely manage to tell her I love her before a boom sounds in the sky and the call cuts off. Ten seconds. I only get to hear her voice for ten seconds or so...”

“What about your other family?”

“I have none. My wife is all I have.”

Old Man Scho murmured.

Real name: Emit Schopenhauer. Alias: Swordmaster.

I felt I understood why he was so obsessed with gaining overwhelming power.

With each successive run, Old Man Scho's capacity for alcohol grew. On the ninth run, he'd tasted soju and declared, “This isn't liquor.” By the nineteenth, he was drinking three bottles in one sitting.

“Even if I drink myself half to death like this, my liver resets when I regress. That's a bargain, wouldn't you say? Hahaha...”

Despite his words, his expression was far from cheerful.

By this point, we—he—had endured roughly 120 years, counting all the time spent across regressions.

In contrast, he'd spoken with his wife for a mere 120 seconds or so.

The old man's journey across the desert for a single sip of water was growing ever harsher.

“There must be someone with a teleportation ability.”

At some point, Old Man Scho's goal began to change.

“Pardon?”

“A teleporter, I mean. If I can just find one, I can rush to my wife the moment the regression begins.”

“But... old man. Even if there's a teleporter somewhere in the world, how would you meet them within a minute? Even you and I don't meet up until half an hour after we regress.”

“...”

Old Man Scho fell silent.

Even I could tell that wasn't a silence of agreement.

The companion who had spent a hundred years trying to prevent the apocalypse with me became consumed by increasingly strange ideas. He muttered incessantly.

“If we find resurrection magic, couldn't we bring the dead back to life?”

“If I become able to copy other people's abilities, and acquire teleportation and telepathy, I'll surely be able to solve everything within a minute.”

“I can do it. I'm certain I can.”

It was like a sandcastle crumbling away.

The collapse reached its climax on the twenty-third run.

As soon as the regression began, I followed my usual route. After clearing Busan Station, which had turned into a dungeon, within thirty minutes, I headed to our agreed meeting place. It was a hideout we'd discovered on an earlier run.

“Huh? Old man? Old man, are you here?”

There was no one in the underground training center. I couldn't even find any sign that someone had been there.

“...”

Seized by an ominous premonition, I immediately set off.

My starting point was Busan Station. Old Man Scho's was the former Baekje Hospital building.

I passed an elementary school that had been half destroyed by rampaging monsters and entered the old hospital building. Everyone had already evacuated. There was no one there.

Old Man Scho lay dead on the rooftop.

“...”

He hadn't been murdered.

At the starting point, there was nothing that posed a threat capable of killing Old Man Scho. Not a monster. Not a human. Not even me.

The only person who could kill him was himself.

Old Man Scho's corpse had no head. His body, however, was intact. His left hand clutched a smartphone tightly.

“Fuck.”