Chapter 3
Did my 〈Ultimate Cutesy Overkill Strategy〉 work?
“Kkyu…?”
“Enough. That’s enough.”
The cultivator hurriedly pulled his sleeve free.
“Stop making that bizarre face like some ancient monster.”
“Then you’ll forgive this young lady, right?”
That guy’s ears turned red.
For a brief moment, the cultivator’s killing intent eased.
It seemed to have worked after all.
Yet I couldn’t shake the feeling that I’d lost something precious inside me.
But cuteness alone wouldn’t save my life.
What I needed now was proof that I was more valuable alive.
“Immortal Master… Immortal Master?”
“What is it?”
“Have you confirmed that I’m actually suitable to be a cauldron?”
His eyebrow twitched.
“What are you trying to say?”
“…Qi differs from person to person, doesn’t it?”
“That is only natural. What a foolish question.”
‘Good, I got some information.’
First of all, qi differed from person to person.
That meant there was a good chance my qi wasn’t the kind he was looking for, right?
“Then you can’t use just any woman as a cauldron, can you?”
The cultivator’s eyebrow twitched.
“How could this lord take the tainted qi of a lowly mortal?”
Another useful piece of information.
Not just anyone could be a cauldron.
Some qi was useful, and some wasn’t.
“Have you tested whether my qi is useful to you, Immortal Master—and whether it suits you?”
His eyes narrowed.
Judging by that, he must have just happened upon me by chance.
“You dare test this lord?”
“I wouldn’t dream of it. This young lady is only asking because she’s ignorant. I might be medicine to you—or poison.”
I put on a performance as though I were about to burst into tears.
No man could withstand this.
‘Starting with me, at least!’
“Ahem.”
“Even clear, pure water might contain deadly poison, in this young lady’s eyes.”
“Are you questioning my judgment?”
“No. I’m not saying the Immortal Master is wrong.”
‘Fuck! Why is this guy so damn touchy?’
What mattered here wasn’t who was right or wrong.
I had to preserve his pride while leaving a seed of doubt.
“As I understand it, you said everyone’s qi is different, and that not just anyone can be used as a cauldron.”
“I did.”
“Then I might be useless, too. So I beg you to confirm it yourself, Immortal Master—whether my qi will help you or not.”
The cultivator’s gaze swept over me from head to toe.
“If I’m a useless woman, I won’t help your cultivation at all. So I beg you.”
“Why should this lord indulge your absurd request?”
Here, I had to save his face.
I had to give him a reasonable pretext.
“If I’m useful, I’ll come with you without complaint.”
“Oh? Do you understand what that means?”
“Of course.”
“So-ha!”
Mother grabbed the hem of my skirt.
I couldn’t turn around.
If I looked at Mother’s face, I thought I’d really start crying.
But this wasn’t enough.
He could take me by force,
and if I had no value as a cauldron, he was the sort of man who’d kill me without hesitation.
So I had to prove I was someone more valuable alive.
Think. He’s a cultivator.
I didn’t know much, but surely the Dao was ultimately about understanding the principles of the world.
If so, perhaps he might be interested in a discipline that described the world objectively.
Mathematics?
And this wasn’t just elementary arithmetic, either.
“This young lady has something she would like to offer the Immortal Master. It’s also the reason I must stay alive.”
“A reason you must stay alive. That interests me. Very well, I’ll hear you out.”
“If I may, there is a book in my room.”
“What value could some mortal’s book have to this lord?”
“It’s a book about mathematics.”
“You think you can beg for your life with mere counting and arithmetic?”
“Please, just take a look.”
I pressed my forehead to the floor.
“It’s a book about infinity.”
The cultivator’s eyes changed.
“Infinity?”
“A theory about numbers without end—immeasurable numbers.”
“You speak of infinity, which should be the domain of immortal cultivation? And you’re a mere mortal.”
“If you decide my theory has no value, you can kill me then. It won’t be too late.”
“……”
“If you’ll allow it, I’ll bring it to you.”
His suspicious expression lasted only a moment.
“Where is it?”
“Pardon?”
“The location of your residence.”
“Ah, over there.”
He took the bait.
It was a gamble, nothing more.
Wasn’t he a cultivator who enjoyed eternal life?
Surely it was only natural that he’d be more sensitive to infinity than a mortal.
He waved a hand in the direction I’d pointed.
Crash!
My bedroom door was ripped right off.
The things inside were caught in a fierce gust and spilled outside.
Everything in the room was swept out by the wind.
The bedding, paper, brushes, and…
even my underwear went flying around the courtyard.
But I had no time to feel embarrassed as a woman.
An old book was sucked into the cultivator’s hand.
It was none other than 「Set Theory」.
‘Perhaps this, too, was fate.’
He flipped through the pages and showed interest.
“Immortal Master, do you think all infinities are the same?”
“How can there be any difference in something without end?”
He took the bait.
“I believe infinity can be large or small.”
The cultivator’s eyes narrowed.
“Sophistry.”
“Would you allow me to explain?”
He answered with a nod.
“Let us suppose there’s an inn with infinitely many rooms, the Infinite Inn.”
“Where would you find such an inn?”
“It’s a supposition.”
“You can just call it infinite and make it so?”
I used a broken table leg as a pencil and drew on the floor.
“This inn has infinitely many rooms. But today, just like now, it’s packed with guests.”
“Meaning every room is occupied.”
“That’s right. If one more guest arrives, what should the innkeeper do?”
He scoffed as if asking why I’d even ask.
“The rooms are full, so he should turn them away.”
“No. He can take them.”
“Did you not say there were no vacant rooms?”
“He can still take them.”
The cultivator’s eyebrow twitched.
“How?”
“First, move the guest in the first room to the second room.”
I drew a line on the floor.
“Move the second guest to the third room, the third guest to the fourth. What happens if every guest moves over one room?”
“The first room would be empty. Wait, a vacant room would appear…”
“That is infinity.”
He looked thoroughly disappointed, as if his hopes had been raised for nothing.
“That’s nothing but a word game. You’ve only added one person. What does that have to do with infinity?”
“Then what if infinitely many guests arrive?”
The cultivator’s eyebrow twitched.
“The inn is already full. You can take one more with the method you just described, but how could you take an infinite number? Absurd.”
“Move the existing guests into the even-numbered rooms.”
“Even-numbered rooms?”
“Look. The first guest goes to the second room.”
I wrote the numbers on the floor.
1 → 2.
“The second guest goes to the fourth room.”
2 → 4.
“The third guest goes to the sixth room.”
3 → 6.
The cultivator’s eyes widened.
“Then all the odd-numbered rooms would be empty.”
“That’s right.”
All the infinitely many odd-numbered rooms would be vacant.
“You can put the new guests, one by one, into the newly vacant rooms.”
A long silence followed.
“Another infinity fits inside a full infinity…”
The cultivator murmured as if he’d realized something.
“And yet its size hasn’t changed from before.”
“With ordinary numbers, it grows each time you add one.”
I looked him straight in the eye.
“But infinity remains infinity even if you add one, and it remains infinity even if you add another infinity.”
“Fascinating. Profound. What a wondrous principle.”
“There’s something even more wondrous.”
“What?”
“Not all infinities are the same size.”
The cultivator’s head snapped up.
“You mean that even something without end can be larger or smaller?”
“Yes.”
“How is that possible?”
I smiled slightly.
“That’s written in the next chapter.”
The cultivator hurriedly turned the page.
For the first time, curiosity appeared in the eyes that had looked at me like a bug just moments ago.
I wrote down the natural numbers.
One, two, three, four…
Below them, I wrote down the even numbers.
Two, four, six, eight…
“The even numbers are only part of all numbers. Since the odd numbers are missing, it looks like half.”
“Naturally.”
“But if you multiply every number by two, you can pair each one exactly with an even number.”
1 → 2.
2 → 4.
3 → 6.
“Neither side has anything left over. They match exactly.”
“Indeed.”
“Look. Even though the even numbers are only a part of the whole, there are just as many of them as there are natural numbers.”
“Sophistry… You’re saying a part can be as large as the whole?”
“Of course, that’s impossible in a finite world.”
I looked up at the cultivator.
“But it’s possible with infinity.”
“Then what are these larger and smaller infinities you spoke of? By your explanation, aren’t they all the same?”
He’d hit the heart of it.
He was sharper than I’d expected.
“There are infinities that can’t be numbered using the infinity of the natural numbers.”
”There are differences even among infinities?”
“That’s right.”
I wrote 0 and 1 on the floor.
“The natural numbers go on forever. But…”
I drew a number line between zero and one and quickly dotted it.
“There are infinitely many numbers between zero and one, too. But even using the same method, there must be at least one number that can never be matched to a natural number.”
“You mean…?”
“Yes. We can prove that infinities have different sizes.”
There was a long silence as I explained using rational and irrational numbers.
The cultivator couldn’t take his eyes off me.
“Even though it never ends, it has different levels…”
He murmured, as if entranced.
“You mean there can be a greater infinity above infinity, and yet another above that?”
“Well, yes.”
“Full, yet empty; a part, yet equal to the whole…”
He sank ever deeper into his own thoughts.
“Perhaps the path of immortal cultivation is the same. At the place you think you’ve reached the end, a new path begins.”
‘The path of cultivation, huh? I’m the one who wants to know what that is.’
But even an immortal would have a hard time readily grasping the essence of modern civilization.
Even Cantor, the father of set theory, had been put through the wringer by the mathematicians of his time when he first proposed it.
Because it wasn’t merely an expansion of knowledge, but an expansion of the ‘paradigm.’
‘How’s it feel to stand on the shoulders of giants?! Jab, jab, one-two!’
“What is the name of this book?”
“Huuack, cough-cough! Pardon?”
I was so startled that I choked.
I thought he’d read my mind.
But judging by his reaction, he hadn’t.
“It’s called 『Set Theory』.”
“Did you come up with all of this yourself?”
He looked at me suspiciously.
“As far as I know, I’m the only one in this world.”
It wasn’t a lie.
There wouldn’t be any trace of Hilbert or Cantor in this world.
The cultivator stroked the book.
“To contain such vast principles in such a small book…”
‘He really understood it? Do cultivators get smarter, too? Is he a genius?’
By now, I was intensely curious whether he understood it—after all, I was the author of this world’s equivalent of The Essentials of Mathematics.
Was this how a professor felt when they spotted a promising grad student?
But I suppressed my curiosity and chose pragmatism.
“I’ll offer you the book, Immortal Master. In exchange…”
“What do you want?”
“Please show mercy to my parents and the remaining villagers.”
Without taking his eyes off the book, the cultivator sneered at me.
“Why should I?”
“……?”
“I could kill all of you and take everything.”
“You could.”
I readily admitted it.
“But then you’d kill hundreds of innocent people.”
“Pfft. How laughable. Do you think the lives of mortals matter?”
‘Do immortals have no morals at all?’
I decided to approach it from another angle.
“There are still many things I haven’t written in the book.”
The cultivator’s hand stopped.
“The real reason infinities have different sizes.”
Aha.
I folded my fingers down one by one.
“What remains when you subtract infinity from infinity.”
My second finger.
“And what happens when you divide infinity by infinity.”
My third finger.
“If I die, the answers will disappear with me.”
“Are you threatening this lord?”
“How could I dare?”
I quickly pressed my forehead to the floor.
“I’m only…”
Then, in the most respectful voice I could manage, I said,
“I’m merely saying there are still infinitely many things left to tell you.”
It was nothing more than a gamble bordering on a threat.
But what else could I do?
This was the only skill I had, so I had to use all the wit I could muster.
‘Besides, don’t immortals need offerings or something?’
“My villagers may be mortals, but they know how to repay kindness. And mercy is a virtue only immortals can show.”
I bowed respectfully, like I would to my grandparents on Lunar New Year.
“If you show us mercy, I’ll offer you tribute every month to repay your great kindness, Immortal Master.”
“You’re the sort who could be thrown into the sea and still have your mouth floating around.”
“This young lady is overwhelmed by your praise.”
“That wasn’t praise.”
“Please forgive this young lady’s ignorance and foolishness.”
‘Even I think I’m disgusting. Bleeech!’
I even imitated the speech from a historical drama.
And prostrated myself, throwing away all my pride.
It was exhausting.
But perhaps thanks to that?
The mysterious power had already begun to dissipate.
The tension that had been stretched taut had loosened considerably, too.
I’d been on the brink of death, but now I could see hope.
To those who asked, ‘Does that make money?’ when I said I majored in natural sciences, I’d like to say this.
Yes, money? I don’t make any. It doesn’t hold a candle to semiconductors.
But who cares about money?
Now, look closely!
And don’t tell anyone.
〈Science saves lives.〉
Physics~ is the best!
Math~ woohoo☆
......
While I was indulging in that brief daydream,
that bastard calling himself an immortal put the book into some kind of pouch hanging from his waist.
!!!
I couldn’t help being astonished by the sight.
Why? Because the book was much larger than the tiny pouch, yet it fit inside.
‘What, is it connected to a pocket dimension?’
He cleared his throat, and at last I heard the words I’d been waiting for.
“Very well. Since you’ve offered me this mathematical text, I’ll grant your request.”
“You mean…?”
“I’ll personally examine your spiritual root.”
Spiritual root…?!
Right, this is it!
No wonder I had this nagging feeling I was missing the last piece of the puzzle.
The one piece I’d missed was the ‘spiritual root.’
So what exactly is a spiritual root?
Did you ask what the definition of a spiritual root is?
Surely it’s not the lotus root you eat?
Ryu-hahahahaha!
