Knock, knock.
Seoeun, who had been sitting on the hotel sofa, perked up her ears at the sound of the knocking.
Once more, the door was rapped in the same rhythm.
Seoeun scrambled to her feet and opened the bedroom door.
Perhaps tired from sightseeing, Miyeong was lying on the bed, fast asleep.
‘What should I do?’
In the end, Seoeun dragged a stool to the door and climbed up on it.
Peeking through the peephole, she saw a man in a suit and an East Asian woman wearing a scarf standing in a polite posture.
Relieved, Seoeun spoke up in a small voice.
“Who is it?”
When a child’s voice answered, they seemed momentarily flustered. But soon, a reply came.
“We’re from MIT.”
The man held up his badge.
A strange logo mixed with red and white—Seoeun, who couldn’t understand English, tilted her head.
The woman beside him spoke again gently in Korean.
“Hello. I’m Choi Yeji, a graduate student in the MIT Mathematics Department. I came along to help with interpretation. Is your mother here?”
‘Ah! The school that sent an invitation to big brother!’
Seoeun hesitated for a moment, then opened the door.
Creak.
“···.”
A pretty little girl in pajamas opened the door and stared at them fixedly.
The two of them barely managed to hold back their laughter.
The woman held out her palm as if to prove she was harmless. Then she slowly bent down to meet Seoeun’s eyes.
“Hi?”
“Hellloo.”
In response to her greeting, Seoeun replied with a deep bow.
“It’s safer to open the door when you’re with an adult. Especially in America.”
Just as she was about to ask if she could call an adult, Miyeong came out rubbing her eyes.
The woman quickly straightened up and bowed at the waist.
“Hello. We’re from MIT.”
When Yeji sent a glance, the man lightly bowed his head and showed his identification.
“I’m Mark. I’m from the MIT Office of External Cooperation. Sorry for coming at this late hour.”
‘At this hour, all of a sudden?’
The memory of Seoha collapsing in the past flashed through Miyeong’s mind.
Her expression stiffened.
“Did something happen to Seoha?”
Yeji waved both hands.
“It’s nothing to worry about; rather, it’s close to good news. Today, in the research building, Yu Seoha presented some meaningful observations and ideas.
Right now, related researchers have all gathered to verify the data. So he’ll be staying in the lab tonight to continue discussions. Of course, it was Yu’s own decision.”
“He’s staying up all night? Isn’t it dangerous?”
“We’re strictly ensuring safety.
It’s a controlled zone so outsiders can’t enter, and the Dean is carefully looking after rest and meals. We received word that he had soup and sandwiches for dinner just a short while ago.”
Mark held out the shopping bag he was carrying to Miyeong.
“Since there’s a possibility the schedule will be extended, the school asked us to inquire whether you could stay in America longer.”
“Pardon?”
“The school will cover the extended accommodation and meal expenses. These are meal vouchers and tour passes. And there’s a small gift inside as well.”
Seoeun’s gaze turned to the shopping bag.
Yeji smiled and pulled out another small envelope.
“There’s a gift for the little lady too. It’s a doll of our school mascot, ‘Tim the Beaver.’”
The animal with its front teeth sticking out was cute. Seoeun’s expression brightened.
“Beaver?”
“Yeah, it’s a cute animal that builds houses on rivers. You’ll be able to see one if you come to campus tomorrow.”
Miyeong couldn’t compose herself.
Only that morning, she had been thinking, ‘I guess we’ll be going back to Korea soon,’ yet now MIT was asking her to stay longer, even offering to cover the stay expenses.
“Could I possibly speak with Seoha?”
“Right now, equipment is running, so calls are restricted.”
Yeji took out a business card from her wallet.
“But if a gap opens up between sessions, we’ll contact you immediately. And tomorrow at 9 AM, I’ll come to pick you up and give you a campus tour.”
“Has this kind of thing happened often?”
At Miyeong’s question, Yeji thought for a moment, then shook her head.
“I’ve been here for eight years, and this is the first time professors and researchers have been urgently summoned at night. It’s also extremely unusual for the school to support living expenses for an international student.
I suppose that means the school is treating Yu Seoha with great importance.”
Mark made one final confirmation.
“We’ll come again tomorrow morning. If you need anything, even in the middle of the night, please contact us at this number. We’ll pick up right away.”
The two of them bowed politely and walked away.
Miyeong placed the two business cards she’d received from them neatly on the table.
Seoeun rummaged through the shopping bag, took out a gray hoodie, and tried it on.
“Mom, can I wear this tomorrow?”
“Sure, it looks warm.”
Miyeong smiled and straightened the hood for her.
Her son had been far from ordinary since childhood.
At first, she had worried about how to raise him, but now it felt as though he had completely left his parents’ hands.
* * *
A midnight call meant one of two things to researchers.
An accident, or a discovery.
Those who had received the late-night message rode in taxis, hoping dearly that the reason was the latter.
“What’s going on?”
“Dunno, did a project suddenly drop?”
Researchers gathered in the lab one by one. Though it was night, the entire building was as bright as midday.
Their reactions upon entering the lab were all similar.
Their everyday workplace had transformed into an unfamiliar place.
“Good heavens…”
“Oh my god.”
Formulas covering the entire glass wall, tables that had been there that morning all pushed aside, and numerous whiteboards brought from who-knew-where taking their place.
There, several researchers were engaged in heated discussion.
“Even the Deans are here.”
“Who on earth wrote this?”
“Someone explain what’s going on!”
Once most of the researchers had gathered, Leonard stepped forward to explain the situation.
Seoha was feeling an unfamiliar sensation.
There was no need to explain twice to the members here.
“Young man, explain that formula to them.”
Leonard pointed at the glass wall.
They were researchers working in a world-class lab.
They listened intently to Seoha’s explanation and threw out questions without hesitation when needed. In that way, within an hour—far sooner than expected—all the members were able to grasp the significance of what had happened today.
Finally, today’s goal was set.
“Now, let’s begin!”
The researchers moved all at once.
Some rushed to the whiteboards to verify formulas, while others opened laptops and began writing simulation code.
“Data pattern analysis team, to the left!”
Under Leonard’s command, the lab transformed into a battlefield in an instant. Each one moved to verify the hypothesis Seoha had presented in their respective fields of expertise.
“Seoha, this simulation here…”
“Seoha! Take a look at this formula.”
His name was being called from here and there. But Seoha couldn’t feel any fatigue at all.
“Seoha, the phenomenon you mentioned is appearing here too!”
A young postdoc researcher from India was rotating a 3D model in front of a holographic display.
Several researchers crowded in front of him.
“Rotate it 15 more degrees.”
“Wait, what if we reverse the time axis?”
“Let’s overlay the zeta function trace we calculated earlier.”
Watching this scene, Seoha felt his heart race.
It was the power of collective intelligence that he couldn’t feel when researching alone—dozens of experts latching onto a single idea he had thrown out, refining and expanding it.
“Anyone need coffee?”
Someone came in carrying a large box. It was late-night refreshments the school had hastily prepared.
“Thanks!”
“There are more sandwiches outside!”
But no one left their spot. Everyone was focused on their own screens and boards.
As time passed and midnight drew near, a cheer erupted from one side of the lab.
“Yes!”
“We got it! The simulation passed!”
A young East Asian researcher raised his fist high.
Leonard approached with quick steps.
“Are you sure?”
“Yes, I ran it three times and got the same results every time. Within a 0.03% margin of error.”
“Good.”
Leonard clapped his hands. The entire lab paused their work for a moment and looked toward him.
“First verification passed! Keep going!”
Excitement and passion could be felt in his voice.
Seoha and Whitman were standing in front of a whiteboard, writing down new formulas. They wanted to neatly organize in mathematical terms what today’s discovery meant.
‘As expected of an Abel Prize laureate.’
Whitman converted the concept Seoha had explained into a more elegant form. He wanted to teach Seoha as much as possible.
The researchers glanced at them.
Like a grandfather and grandson,
the harmony between two mathematicians with an age gap of nearly 60 years strangely drew people’s gazes.
Until the dead of night, everyone continued working without rest.
But no one complained.
There was nothing more exciting for scientists than being part of research that would astonish the world.
* * *
“Ugh, aren’t we gonna die from overwork at this rate?”
Mike groaned as he sank into a lab chair.
Looking around, he saw researchers collapsed asleep with gowns thrown over them—on sofas, under desks, even on the hallway floor.
They looked like corpses strewn across a battlefield.
“I thought I’d left this kind of thing behind in undergrad…”
Sarah nodded.
It wasn’t until past 6 a.m. that the approximate verification work was completed.
As tension dissipated, researchers who had been running on excitement and adrenaline began collapsing one by one like robots with their batteries drained.
“Uwaaah!”
Someone who had been sleeping face-down on a keyboard screamed and shot up. The simulation program was still running on his monitor.
“Those gentlemen are really amazing.”
Mike pointed with his chin to one side.
Beyond the glass partition, Leonard and Dean Whitman could be seen. The two of them were sitting at a desk, writing a draft paper. It was impossible to think of them as old men approaching seventy.
“The real monster is Seoha. I still can’t understand it. That level of thinking at his age isn’t normal.”
“There are people like that once in a very long time. Beings beyond common sense. They say Eliya Kronen was like that too?”
A silence fell between them.
A topic they wanted to bring up but found difficult.
“If today’s experiment is published as a paper, it’ll be chaos, right?”
Mike finally threw a curveball.
“Of course. It’s like a new clue to the Riemann Hypothesis has been found. Not just physics—the math world will be turned upside down.”
And what he had really wanted to ask.
“We’ll be included as co-authors, right?”
Sarah nodded.
“Leonard said he’d do it that way. Seoha as the first author, Leonard and Whitman as corresponding authors. The rest in order of contribution.”
Only then did Mike let out a sigh.
“Wow! Seoha isn’t even an undergrad, let alone a master’s or PhD student, and he’s already about to get his name on a Nature-level paper.”
“Nothing strange about it. It’s probably not even his first time, is it? I heard he’s already a rising star in math circles.”
A few days later,
the BBC and the New York Times posted new articles almost simultaneously.
MIT’s servers were temporarily paralyzed due to traffic overload.
[Boy Who Proved Four Color Theorem Presents New Clue to Riemann Hypothesis]
[New Breakthrough Opens in Riemann Hypothesis]
[What Happened in MIT’s Lab That Night?]
A powerful clue had emerged for a hypothesis that had seen no real breakthroughs for decades.
If proven, wealth and fame were guaranteed.
The attention of all mathematicians converged in one direction.
The door that Seoha had flung wide open,
was the very beginning of the ‘Grand Riemann Hypothesis Era.’