An apartment in Daejeon,
Park Seongdae, a mathematics teacher at a gifted high school, looked at the reference books piled high on his desk and pressed a hand to his forehead.
The night was already deep, and outside the window it was pitch-black. His mind was the same.
A few days ago, when he received the list of incoming students from the academic affairs office, one student’s name had caught his eye.
Yu Seoha, age 13.
First place individually at the International Mathematical Olympiad,
An elementary school student who had perfectly solved a problem said to be the most difficult in all of IMO history.
The word “genius,” so excessively overused these days, would not be enough to properly describe that child.
His heart felt as heavy as a stone.
“What am I supposed to teach him?”
A master’s degree in mathematics from Seoul National University,
Seongdae had taught countless gifted students over the years, but not once had he ever felt that his own mathematical ability was lacking.
Yet now, he had no confidence.
Even among teachers, there were battles of pride.
And a career that had passed through science high schools and gifted high schools was an effective means of proving that pride.
People asked why he would graduate from such a good university only to become a teacher, but being a math teacher had the appeal of directly guiding a student’s growth.
Students who had only solved problems mechanically opened their eyes to mathematics through his lectures. And through fierce thought and meticulous logic, they finally arrived at a complete proof.
In that moment, the look in the students’ eyes changed.
Teacher Park liked witnessing that moment.
Mathematics was not about finding the right answer, but a language of inquiry and proof. But what help could he offer to a boy who was already walking that path?
His worries only deepened.
* * *
Seoha walked along the route to school.
Spring sunlight slipped between the leaves and shattered across the road.
Cherry trees and zelkova trees lined both sides of the path to school,
And once he passed through here, there would be a flower path where royal azaleas and lilacs mingled.
It was a beautiful landscape, but Seoha sensed a strange air settled over this school like a barrier.
It had been three days since he entered the gifted high school.
Seoha came to a conclusion.
This place was a kind of otherworld (異世界).
A twisted space that existed in reality, yet was not reality.
There was clear evidence for this.
The total number of first-year students was 120.
However, not a single one of them came from a single-mother or single-father household. (The principal had proudly said so during his address.)
Seoha looked up data from Statistics Korea.
According to the 20xx “Survey on the Status of Single-Parent Families,” single-parent households made up as much as 9.3% of all households in the country.
There was no need to calculate it.
The probability that every single incoming student came from a two-parent household was 0.000818%,
One in 120,000.
It was similar to the probability of flipping a coin and getting heads 17 times in a row.
“Terrifying, sample bias.”
It was astonishing that the filter called entrance exams could shake the sample this powerfully.
Therefore, it was a logically valid inference that this place was an otherworld where even the laws of probability and statistics had been twisted.
Someone was approaching.
‘Ah! An otherworlder.’
Kim Eunbin from his class.
In this place, where the male-to-female ratio was 8.5 to 1.5, she was a specimen not easily found.
“Hello.”
Seoha lowered his head and greeted her politely.
Even if there was an age difference, she was his classmate, so perhaps this style of greeting was a little excessive.
But through the IMO, Seoha had realized that being as polite as possible to people older than him, regardless of the reason, made life easier.
However, no reply came.
Seoha raised his head and looked at her.
The characteristic of otherworlders was that they were always doing something.
Were their ears vulnerable? Aside from class time, they always protected their ears with earphones.
They always had something to read in their hands.
Step, step.
Eunbin walked over and met Seoha’s eyes. Then she passed by without any reaction at all.
Seoha nodded, saying, “As expected...” With this current case, the probability had dropped even lower.
41.4%.
It was another law of the otherworld.
Having grown up in the countryside, Seoha had always greeted every neighbor he met on the road first. Then, with a 100% probability, a greeting would return. It was as natural as air.
But here, it was different.
The eyes of the students passing by on the road or in the hallway were always buried in books or tablet screens.
Even if their eyes met, they looked away and passed by, just as she had now.
Less than two hours after enrolling, Seoha had detected this abnormality, and he was currently collecting data for research.
‘Mom, Dad, and Seoeun.
This is a place where the laws of mathematics are distorted, and even humanity’s most basic social agreements are not observed. I’ll be able to do well, right?’
Though it had only been a few days since he left, Seoha already missed home.
* * *
A fast-food chain in front of the school,
Seoha sat at a table with a tense expression. Across from him, Sujeong, who had now become his senior at school, rested her chin on one hand and smiled at him with her eyes.
“Is the world coming to an end? I can’t believe I’m going to the same school as you.”
Unlike her words, her face looked as if she was having the time of her life.
She was a third-year starting this year, and Seoha was a new student.
Until not long ago, the distance between them had been that of an elementary school student and a high school student. But now, they were senior and junior at the same school.
‘It’s obvious he’s going to suffer, but I can’t just pretend not to know.’
As a senior who had experienced this school first, she had many things she needed to tell this pitiful little lamb.
In truth, Sujeong was a little excited. She had entered elementary school one year earlier than others and graduated middle school early.
A two-year age gap with her classmates.
There had always been a sense of distance between her and the friends in her class.
Everyone around her was older; Seoha was the only younger human she talked to.
So Sujeong decided to generously pass on all the know-how she had acquired to Seoha.
“Now, what did I say?”
At Sujeong’s question, Seoha flinched.
“You said that 90% of the students who ask me questions already know the answer and are asking anyway...”
Snap!
Sujeong snapped her fingers.
“Exactly! Isn’t it really ridiculous? Why would they ask if they already know?”
Seoha’s expression went blank.
“Isn’t it because they’re trying to confirm whether what they know is really correct?”
What other intention could there possibly be?
“Tsk, tsk! It’s the exact opposite.”
Sujeong narrowed her eyes as if mocking him, then shook her head.
“What?”
Sujeong looked at Seoha with pity, her expression saying, What am I to do with this poor little lamb!
“They’re trying to confirm whether you might not know something they know.”
Seoha tilted his head, still not understanding.
“Is it... showing off?”
“No? Rather than that, it’s probably that they want to protect themselves.
‘Even Yu Seoha, who is su-per good at math, doesn’t know this, but I do!’ Something like that. If they can secure even the tiniest bit of evidence that there’s at least one area where they know more than you, they can preserve the bare minimum of dignity.”
Sujeong blushed, seeming embarrassed even though she was the one who had said it.
At one time, Sujeong had felt something similar toward Seoha. But before an exceptional human, all people became equal. Sujeong had noticed and accepted this early on.
‘I don’t know if he’s the pitiful one, or if the kids in his grade are the ones I should feel sorry for...’
If you keep staring at a tree you can never climb, not only does your neck hurt, but your heart gets wounded too. Sujeong knew a few boys who had become jealous of her and gone dark.
It would be easier for everyone if he simply showed overwhelming skill, the way he had with her...
It would be nice if they saw his result of first place at the IMO and acknowledged him, but the bloated egos of gifted high school students did not yield superiority to others that easily.
‘Was I like that too?’
She probably had been. She had seriously believed there was no one in the world she couldn’t beat.
Her face burned.
Besides, Seoha had a strangely infuriating side to him.
Especially that face of his, which seemed to say, “Unlike you people, I know nothing of jealousy.”
“Why don’t they return greetings?”
Seoha asked Sujeong about something he had been curious about all this time.
“They were all wearing earphones, right?”
“I... think so.”
Sujeong nodded as if she understood.
“That’s like an unspoken rule at this school. It means, I’m busy doing something else right now, so I won’t give or receive greetings.”
Sujeong stirred her cola straw and laughed.
“Selfish, right? They’re saying they’ll protect their own world, even if they have to omit the bare minimum of courtesy. You hate it when your flow gets interrupted while solving a problem, don’t you? The kids here are kind of like that.”
“Oh!”
The question had been answered.
At Seoha’s admiring gaze, Sujeong felt satisfied.
“So how worried do you think I was? How hard would it be for a kid like you, smelling of the countryside, to live here?”
It was not easy, but it was certainly interesting.
Seoha repeatedly thanked Sujeong and returned to school.
On the way to the dormitory, he organized his thoughts.
In other words, the members of this place were...
“They have strong self-consciousness and are selfish. They have no interest in others and are extremely individualistic. There is room for them to show exclusivity toward people who do not come from the same population group.”
The more he put it into words, the worse it became.
Seoha, who had never had any major problems with friendships until now, had come here and found himself facing an enormous challenge.
* * *
Contrary to Seoha’s thoughts, the students in his class had a subtle interest in him. It was just that their way of expressing it was a little twisted.
On the surface, they each opened their problem books and scribbled formulas on their tablets as if nothing was happening. But their gazes kept drifting toward Seoha, who was sitting in the very front seat.
Of course, what each of them was thinking was different.
‘Is he really on a completely unreachable level?’
‘Maybe he actually isn’t that different from me?’
‘How good can a kid be, anyway?’
‘He seems like he’ll become something big later. Should I try to get close to him now?’
‘Mom told me to bring him over sometime...’
‘I heard a rumor that the genius Shin Uhyeon mentioned is him.’
‘I have one really hard problem. Should I ask him?’
‘Ah, should I have greeted him before?’
While everyone was thinking of something else, math class began.
Rattle.
Teacher Park opened the classroom door and came in.
Today was his first class with this class.
After worrying about it all night, he had concluded that he first needed to accurately assess Seoha’s ability.
“Today, we’re having a quiz.”
“From the first class?”
“What’s the range?”
“Will it count toward our grades?”
Various reactions poured out from the students.
Tests at gifted high schools were famous for their high difficulty.
Last semester, the top student in the entire school had an average of 57 points, while the bottom student in the entire school had 46 points.
But Teacher Park had designed this test so that the average would be 30 points, in order to accurately evaluate Seoha’s ability.
It was different from the IMO.
Since many problems had to be solved within a set time, proficiency was important.
Rustle.
Teacher Park handed out the test papers he had prepared in advance.
The test paper was four pages long, with a total of ten questions.
Next to each question, “key words” were written in small letters. Invariant, expected value, rationalization, symmetry, limiting structure, graph connectivity, pigeonhole, generating function.
The students’ eyes scanned there first.
Key words—not meaning that they would tell them the answer, but a guide specifying through what lens they should view the problem.
‘Without even that, it would be too difficult...’
“You have 35 minutes!”
At Park Seongdae’s words, the classroom fell silent all at once.
“I’ll be looking at the flow of the solution rather than the answer.”
Scratch, scratch.
The pencils all began moving at once.