Late that night, Seoha could not fall asleep.
The notebook spread open on his desk blurred before his eyes. His eyes were tired, but his mind was growing clearer and clearer.
“Why isn’t it coming out?”
Seoha rose from his seat and brought over the board.
Even today alone, he had erased and rewritten it dozens of times. But no matter how many times he organized it, there was one part that kept bothering him.
“I have to deal with this before moving on…”
The process of minimizing the energy function using variational calculus, the starting point and core of the proof.
‘ΔE=0⇒Euler–Lagrange equation…’
The formula flowed smoothly, then at some point came to a dead stop.
It was like driving along a well-paved road only to suddenly enter a rough gravel field.
‘Is there no helping it?’
With an uneasy expression, Seoha looked into the mirror.
“Ducky, what do you think?”
The moment Seoha called the name, the atmosphere changed as if a switch had been flipped.
A strange stillness, as though the center of gravity of his personality had shifted.
Thump, thump.
His heartbeat quickened, as if his body needed more fuel to maintain itself.
At last, a part of Seoha’s mind opened with a sharp click.
“Hmm.”
A different air from usual settled in his eyes.
Shooting out a gaze as sharp as a beam of light, he scanned the board.
“Let’s look from the beginning again. Don’t do anything useless, just help me.”
Seoha did not want to summon this uncomfortable cohabitant if he could avoid it. The various side effects were exhausting. But it, too, was a part of him; when he needed help, he had to accept it.
The energy function as seen through Ducky’s eyes.
The functions writhed and took shape. A landscape called “energy”—the equations began to gain three-dimensionality. Curves rose like ridgelines, and slopes broke off like cliffs.
Beneath the integral sign, an endless field stretched out.
‘So this is what it felt like.’
Seoha looked around.
Before the place where the path ended, a vast mountain range of energy rose up.
“Is there no other way?”
It was a path no one had ever managed to pass through until now.
A mountain range that retained its primordial form, as if rejecting the touch of human hands.
It stood silent, like a predator lying in wait for an intruder.
Seoha slowly approached it.
Sheer precipices and high ridges. The cliffs dropped vertically like blades, and it seemed that if he set foot there, his very form would vanish in an instant.
“No wonder I couldn’t find a side path in a place like this.”
One more step, and he would be in the domain of the energy mountain range.
Seoha tried putting his foot forward.
Ruuuuumble—
Had it sensed the intrusion? The entire mountain range made of functions shook violently.
The ground split open with a crack, and another ridge rose up from the floor.
As if he had expected as much, Seoha let out a faint laugh and took a step back.
“You really were an incredible one, weren’t you?”
Aside from the Riemann Hypothesis, it was larger than any problem he had ever seen.
There were no shortcuts. He had no choice but to take the orthodox path and cross it one step at a time.
“Hoooo.”
Seoha exhaled at length.
His body felt hollow. Like an F1 driver accelerating without a thought for what came afterward and burning through all his fuel in an instant.
‘I shouldn’t have left the CD in the lab…’
Even that, now that he had listened to it too much, was starting to lose its effect.
Before he knew it, quite a bit of time had passed.
He was thirsty. Not for water, but for glucose; his body was fiercely craving sugar.
Seoha slowly pushed back his chair and stood.
At dawn, even the slightest movement made a loud sound.
Tiptoe, tiptoe—
He walked on the tips of his feet so as not to make a sound.
When he reached the kitchen, he carefully opened the refrigerator door.
Chik—
‘What’s in here?’
A few containers of side dishes, bottles of water, meat that had been thawed for the morning, and salad vegetables. That was all.
‘This won’t do…’
Seoha wore a troubled expression.
‘Huh?’
Just as he was about to close the door, he looked into the corner and saw a pudding with a cute character drawn on it.
Seoeun’s favorite snack in the whole world. Seoha unconsciously reached out his hand.
He needed sweetness.
His body urged him to hurry up, tear off the packaging, and eat the pudding.
Just imagining the sweetness entering his mouth made his body feel warmer.
The instant he was about to peel off the wrapper, he came sharply to his senses.
Self-loathing washed over him at the fact that he could not even control something so trivial.
‘She’d definitely be disappointed, wouldn’t she?’
Pudding for dessert after breakfast.
It was one of the joys Seoeun could not do without in her day.
‘Yeah, this isn’t right.’
Shaking his head, he was about to put the pudding back when a small voice came from behind him.
“…Oppa?”
Seoha flinched and turned around.
There stood Seoeun, hugging a beaver doll.
Wearing pajamas, Seoeun rubbed her sleepy eyes and looked at Seoha.
“Oppa, do you want to eat my pudding?”
Seoeun’s voice trembled at the end, as though she were about to cry.
“No!”
Startled, Seoha hurriedly shut the refrigerator door.
“I was checking the expiration date. I didn’t want you to eat it and get a stomachache.”
“Really?”
“Yeah!”
“If you want to eat it, Oppa, I don’t mind giving it to you.”
“Absolutely not! You know Oppa doesn’t really eat sweet things.”
Seoeun tilted her head, then nodded as if she understood.
“…That’s true. Is the date okay?”
“Huh? Oh! It’s totally fine. I don’t think it’s been long since Mom bought it.”
“Then it’s okay if I eat it in the morning?”
“Yeah.”
Seoeun’s face brightened.
“That’s a relief, hehe.”
After taking Seoeun back to her room, Seoha let out a sigh of relief.
He had almost tarnished the dignity of an older brother.
‘I should never do this at home.’
It was a side of himself he never wanted to show his family.
* * *
The next morning,
Sri cleared his head with coffee, then headed to Seoha’s lab.
His heart trembled.
But along with it came anticipation at the thought of researching mathematics together with him.
Beep—
When he held up the key card he had been issued, the door opened.
He cautiously stepped inside. Then he looked at the front of the lab and was greatly startled.
“What is this?”
Sri’s eyes widened.
A massive drawing covered the blackboard.
‘Is it a doodle?’
No.
It was a precise form in which not a single line or point had been drawn carelessly.
Curves were stacked in layers like a mountain range, and beneath them, arrows symbolizing gradients fell as steeply as cliffs.
“This isn’t just a graph…”
It was not a simple sketch.
Each curve visualized the gradient S (∇S * a vector indicating changes in the surface), and the parts that bent like cliffs marked the “points where singularities occurred” that Seoha had agonized over all night.
The undulations of the curved surface were connected smoothly, as if following the flow of the variational formula.
All of it harmonized together, giving him the illusion that he was looking at a landscape.
In that instant, the function he had been wrestling with for the past month surfaced in his mind.
“No way…”
Sri’s eyes flew wide in shock.
“Did he draw the energy function itself?”
“Yes, that’s right!”
Seoha’s voice came from behind him.
He was holding a large donut box.
Rustle.
“Would you like one?”
When he opened the box, a rich smell of sugar poured out.
Glazed donuts heavily coated in white sugar. Just looking at them felt like it would make one’s blood sugar explode.
A snack Americans went crazy for.
Chomp—
Seoha took a big bite of a donut, then wore an expression as if he had come back to life.
Sri also accepted a donut.
When it came to sweet things, India was no slouch either.
“Thank you.”
Eating it with strong Americano mellowed out the sweetness, making it pair well.
Beep—
“Good morning, Seoha.”
Theo came in, greeting him in the morning.
He spent most of his day here.
“Come on in, Theo.
This is Sri. We’ll be researching together from now on, so I hope you two get along.”
Sri sprang up from his seat and bowed his head.
“I’m Srinivasa Krishnan, a first-year master’s student in mechanical engineering.”
But Theo did not hear him. All his attention was focused on the landscape Seoha had drawn.
“Ah… hmm. Huh?”
Making sounds like interjections, he observed the blackboard for a long while.
Then he took out his camera and snapped a photo.
Click.
“This is an image of the energy function, right?”
Sri was startled.
He had recognized the drawing because he had been discussing it with Seoha for a long time.
But how on earth had Theo known?
From what he could tell, Seoha had not shared anything about the energy function with him.
“As expected, Theo can recognize it.”
When Seoha gave him a thumbs-up, Theo turned his head, looking embarrassed.
“Why this, all of a sudden?”
“I’m thinking of trying to find the minimal energy surface with Sri. I believe images are very important when dealing with difficult problems.
I tried to depict the waves of the energy function as I see them, and it makes me proud that both of you recognized it.”
Theo’s gaze brushed over the donut box sitting on the desk.
‘Did he enter that state of extreme focus again? It would be a disaster if he collapsed.’
“I’d like all of us to solve this together. What do you two think?”
Seoha said it casually, but silence briefly flowed between the two of them.
Sensing the atmosphere, Theo quietly raised a hand.
“This was a project you two started, wasn’t it? I don’t think it would be appropriate for me to join now.”
Role conflicts, struggles for leadership, questions of contribution.
Having come from Stanford, Theo had seen countless such problems. Since Sri was someone Seoha had his eye on, Theo thought it would be best for him to take a step back here.
“Hm? I’m afraid not.”
At Seoha’s refusal, Theo blinked.
“What do you mean…”
“If the three of us work on it, we can do much better. Theo, you’re strong in variational calculus and analysis. Sri can offer not only mathematics, but also the engineering perspective I lack.
This is a hard problem. Even if we pour in every resource we have, we don’t know when we’ll be able to solve it. And yet someone who could be a great help says he’ll sit out…”
Seoha stared straight at Theo.
“Ahem!”
To think Seoha had acknowledged him to such an extent.
Theo let out an unnecessary cough.
“I agree as well. What matters is solving the problem. Everything else is secondary. Let’s try everything we can.”
At Sri’s words, Seoha nodded repeatedly.
“Then the three of us are a team now.”
“A team?”
“Is that how it works?”
“Then what’s the team name?”
“Pardon? Do we need something like that?”
Theo looked frustrated.
“Of course we do. Later, when articles come out and when we publish papers, having a team name makes citations easier. It’s also much more convenient when registering copyrights or patents.”
“Oh!”
“Wow!”
The two of them looked at Theo with eyes full of respect.
Theo had a premonition that he would end up taking charge of all the paperwork on this team from now on.
“MIT already has a lot of research units divided by team, so we’ll definitely need a name.”
“Yes, I understand. Then the name…”
Seoha brought a hand to his chin and thought for a long time.
“Can’t we just call it ‘Team Yoo Seoha’? You’re the identity of our team anyway.”
At Theo’s words, Seoha recoiled and waved his hands.
“Absolutely not. If someone heard that, they’d think I was an egomaniac.
Instead, how about ‘Team Apex’?”
Theo nodded in satisfaction.
“Apex… Not bad. Since Seoha is with us, this team has no choice but to aim for the peak anyway.”
“That’s what you meant?”
Sri was startled by the scale, which had grown beyond his control.
“Obviously.
If this team produces poor results, it’ll be one hundred percent because of either you or me. Seoha has already turned the mathematics world upside down several times on his own.
So if you’re not prepared, it would be better for you to leave even now.
Surely you didn’t come here with a half-hearted attitude, did you?”
Sri bit his lip hard.
“I’m prepared. If it means making this project succeed, I’m willing to stake the rest of my life on it.”
The atmosphere sank heavily.
“Don’t worry. You two are the most outstanding mathematicians at MIT.”
At Seoha’s praise, their expressions softened as if by magic.
“Since it’s a hard problem, I can’t guarantee anything. But let’s do our best.”
“Of course.”
“Yes!”
A new nameplate was hung on Seoha’s lab.
[Team Apex Lab]
—Seoha Yoo, Theodore Ranford, Srinivasa Krishnan
Compared to the fame they would one day gain, it was a very modest beginning.