Allen woke from sleep, clutching his head that felt as though it would crack.
"Ugh, my head..."
He groaned, pressing his hand to his forehead.
When he threw off the blanket, a sweet smell of alcohol wafted up.
'Ah... I was invited to a meal.'
His memories connected faintly.
A garden, samgyeopsal on the grill, glasses of kimchi jeon and makgeolli.
The laughter of the kind-looking couple and the child's giggling; after that was a complete blank.
"You're awake?"
A soft voice came from the doorway.
Seoha approached, carrying a golden-colored drink on a tray.
"This is good for hangovers. Please try it."
Allen smiled awkwardly and accepted the cup.
*Gulp, gulp.*
As the honey water flowed down his throat, he finally felt his stomach settling a little.
"I'm truly sorry. To think I got drunk while visiting as a guest."
Allen had no face to show Seoha.
It was the first time since his undergraduate days that he had shown such a disheveled side to anyone else.
"It happens often in Korea. My parents love having guests."
Seoha shook her head as if to say not to worry.
"Seoha! Tell the guest to come out!"
A voice called from the kitchen.
When he came out, a meal was laid out on the dining table.
Allen's eyes widened at the food he was seeing for the first time in his life.
Miyeong glanced toward Seoha as if telling her to explain.
"It's called bugeotguk. In Korea, you always eat this the day after drinking. Though I like it regardless."
Since it would be rude to refuse the prepared food, Allen quickly took his seat.
Steam rose from the bowl.
Eggs were stirred into the clear broth, and red chili peppers and green onions were finely chopped and added for color and flavor.
"Please eat. It's hot, so be careful."
Allen carefully lifted his spoon and tasted the soup.
*Slurp.*
A hot, savory taste brushed the tip of his tongue.
But it was not pungent. The soft taste of the eggs probably mitigated the saltiness of the broth. The dried pollack flakes, alive in texture, gave off a savory taste with every chew.
The sparsely placed red chili peppers gave a mild stimulus to his tongue dulled by alcohol, and the taste finished with the refreshing scent of green onions that rose at the end.
"Mmm, this is good. It's low in oil and clean-tasting, so it doesn't burden the stomach."
"Right? It's one of my favorite dishes."
When Seoha translated Allen's words, Miyeong showed a nonchalant reaction, saying, "After drinking so much, even boiled stones would taste good."
When Seoha relayed those words, Allen laughed, his shoulders shaking. Her words had reminded him of the European folk tale, *Stone Soup*.
"Kwahahaha! It's been a really long time since I've had such an enjoyable weekend."
He had thought McMuffins were the best for hangovers, but the Korean hangover remedy restored Allen's body in a way entirely different from the American kind. He felt cells coming alive as his body warmed.
Allen emptied his share of the bowl cleanly.
After having the hangover soup and drinking cold water, his senses returned.
"Now then, I should achieve the purpose of my visit here, shouldn't I?"
"Yes! Let's go upstairs."
Allen had already grown comfortable speaking with Seoha.
As he climbed the stairs, Seoeun, who had been secretly watching from the second floor, ran off in a flash with her beaver.
"She's just shy."
Allen, who had no family, found Seoeun, who was of daughter age, adorable.
"That's too bad."
It seemed he would have to wait until next time to get close to her.
Allen suddenly noticed that his drinking buddy from yesterday was nowhere to be seen.
"What about Cheolho?"
"He hasn't gotten up yet."
"Haha! Well then, I've at least managed to preserve some American male pride."
When Seoha rolled her eyes, he cleared his throat.
"Come in."
Seoha's room was clean, as expected.
A bookcase excessively large for the room filled one entire wall.
Various theses, theoretical texts, and mathematicians' autobiographies were packed tightly on the shelves.
Half-completed formulas were visible on a large board standing in the corner of the room.
Complex symbols and curves, a zeta function matrix with question marks marking where something was not working out.
On one side was written a theorem regarding the 'Self-referential Phase Variable' he had been curious about.
"Is this the algorithm you mentioned?"
"Yes."
Allen unconsciously stepped up to the board.
That space where lines and symbols intertwined and scattered was like a map with Seoha's thought process visualized as it was.
Allen stood for a long time, following the formulas written on the board.
"It's a structure where the system accepts its own output as input again. Simply put, each signal in the city determines its phase by referring not only to its surroundings but also to its own state."
"Hmm..."
Allen glared at the board with his arms crossed.
Having woken up, his head was clear. To preserve at least minimal dignity, Allen desperately chased the formulas with his eyes.
"Ordinary feedback loops reference external variables, but here self-reference is included. You mean it recognizes and corrects its own phase deviation over time?"
Fortunately, Seoha nodded as if he was not wrong.
"That's right. Even without external central control, the entire network can autonomously synchronize phases.
Each node records its own state and uses that information as the criterion for judgment in the next cycle."
Allen listened seriously to Seoha's lecture, like a student who had returned to university.
Seoha's explanation continued at length.
And by the time it had grown pitch dark outside, he was finally able to completely understand Seoha's algorithm.
"Wow..."
Allen was briefly at a loss for words.
This was not a paper she had set out to write. Naturally, the preparation period must have been short. Yet with only the theme of signal optimization, she had created a theory to this extent.
"This isn't traffic theory, is it? It's something entirely new, combining phase theory, dynamics, and even cognitive systems.
It's as if I'm looking at a signal system from 30 years in the future. Would this even be possible then?"
A system close to the ideal that any urban engineer would dream of.
A fierce desire to realize this bloomed in Allen's heart.
"I'm not sure about that since it's not my major.
Cities repeat choices every moment, don't they? I wanted to try modeling centered not on traffic lights but on people's decisions."
"Because cars are ultimately driven by people."
Seoha found it odd that Allen showed interest in this.
"Do you think it can be applied to Boston?"
"Hmm..."
Allen placed his hand on his chin and thought deeply about something.
"Seoha, your theory is genius. No, it's so excellent that it can't be explained with such common words. Signal optimization is a theme that many countries are researching even now.
But I guarantee that no country's current system is more perfect than yours."
Seoha's face turned red at the excessive praise.
"There are still many flaws. Right now it's closer to a simple concept diagram. To actually apply it, we'd have to design it anew from the beginning.
But if we could use all of Boston's city data without restrictions, I could create a much more sophisticated algorithm."
Allen wrapped his hands around his head.
"Of course. You created such a high-dimensional algorithm from fragments that can hardly be called data. I'd give you full authority if I could, but reality isn't that simple."
"Is there some problem?"
"There are as many interests in a city as there are people. And depending on politics, capital, and power, the direction of policy changes from moment to moment.
I'm saying the budget approved today could disappear next year."
"What about the mayor?"
He shook his head.
"He's a timid, conservative person, so he won't cooperate with this. Yet for all that, his hunger for power is tremendous..."
Allen stopped speaking, as if he had thought of something.
"Seoha! How long do you think it will take for this algorithm to show results?"
"I think within a few months, all citizens would be able to feel it. Because commute times would get faster."
Allen fell into thought.
"...Perhaps I might be able to persuade him?"
Allen swept the papers scattered on the desk cleanly into his briefcase.
"Seoha! Let me borrow these materials."
Allen hurriedly greeted the couple and rushed off toward home.
* * *
Late afternoon, Boston Mayor's Office.
When the elevator doors opened, Allen walked in carrying a heavy leather bag.
"Sir, you don't have a schedule with the Mayor today?"
The secretary spoke with a troubled expression.
"I have something to report to the Mayor."
"Please submit it as a meeting agenda. We should be able to schedule something for next week."
He yelled, uncharacteristically.
"Then say it's an informal agenda!"
Without waiting for the secretary, Allen walked heavily toward the mayor's office door and opened it.
The secretary chased after him with a flustered face, but he had already gone in.
* * *
"What is it, Allen? What's the matter?"
Mayor Patrick set down his golf club, having been practicing his putting.
"You look like you have something to say, but just leave the documents and go. Right now is the precious 30 minutes when I can breathe for the only time in my day. You are ruining that."
Allen quietly opened his briefcase and took out the materials.
"Just give me 10 minutes. It's very important."
Patrick sighed.
"10 minutes. I'll be timing it, so don't complain later."
As if this wasn't the first time, Patrick took out a stopwatch from his drawer and pressed it.
*Beep.*
[00 : 09 : 50]
"This is a signal optimization algorithm developed by MIT researcher Seoha Yu."
Seoha was an undergraduate, but also a researcher.
"You're tormenting me again!
You know perfectly well there's no budget or manpower! I spent today fighting with the city council over bus route adjustments too."
Veins bulged on Patrick's face, as if it were no lie.
"It must be done now. At least look at the report."
"Hmph! Are you looking down on me because I'm a liberal arts major? I bet it's full of those arrogant numbers."
"You'll understand when you see it."
The first page of the report began with the conclusion.
[Downtown Boston Traffic Congestion Rate, 37% Decrease Within 6 Months]
He turned the page as if possessed.
The report contained graphs simulating the actual traffic network and curves showing estimated congestion indices by commute time.
Patrick furrowed his brow.
"What kind of joke is this? Did you make this yourself?"
"An MIT research team designed it. I only vetted whether that model could work in a real city."
"Scholars don't know reality. Do you truly think this city moves like a graph in a paper?"
"Mayor. Do you think I don't know the field?"
Allen glared at the mayor.
Overwhelmed by the momentum, Patrick put down the paper and leaned back against the sofa.
"I'm not a fool. Such magical things cannot happen in reality."
"It's possible."
"Can't you say anything with words?
If this fails, you can return to being a researcher. But what about me? My political life ends right there."
"This is a sufficiently viable theory. Mayor, you only focus on failure, so then what do you think happens if we succeed?"
"Tell me."
"Patrick, how long do you intend to remain the mayor of one city?"
Patrick lifted his back from the chair.
"What do you mean?"
"A mayor who solved Boston's hellish traffic problem could aim for governor, senator, or even higher positions, don't you think?
You'd gain nationwide fame in an instant. People will remember you as a successful innovator."
Silence flowed.
Patrick picked up the paper again and looked it over.
"I know you are an honest man. So speak honestly. Is this truly possible?"
"If you give me full authority, it's 99% possible."
"Full authority?"
"Budget, personnel, administration—everything regarding this project must be entrusted to me. If we're tied up by committee or city council approval procedures, we can't do anything. Of course, you'll have to block external pressure too."
Patrick had an expression of disbelief.
"Are you asking me to be publicly executed in the square?"
"I will definitely repay you."
Allen took out a letter of resignation and placed it on the desk.
"If I start this, I can't go back to being a researcher.
If I succeed, I'll gain fame, but if I fail, no one will call on me anywhere. A researcher who ruined a large project is more miserable than a failed politician."
*Creak.*
Patrick pressed his hand to his forehead.
After pondering for a long while, he rose.
"I need time to think.
I have a professor I know at Harvard; I'd like to get his opinion. Bring me the full paper, not just the report."
"Understood."
Allen smiled and rose from his seat.
'He's almost hooked.'
He would be imagining himself having become governor right now.
"Allen."
"Yes?"
Allen, who had been about to leave, turned around.
"What kind of person is the author of this paper? To have enticed someone like you so..."
Allen thought for a moment and answered.
"A mathematician whom MIT is carefully nurturing.
I think that in 20 years, MIT will far outstrip universities like Harvard or Stanford. For no other reason than simply because Seoha is there."
"That damn MIT connection..."
Patrick shook his head and gestured for him to leave.