Chapter 189: Did I Enter the Wrong House?

April 5, 6:00 a. m.

Xu Xu Qingzhou picked up his suitcase and went downstairs, ready to leave the city where he had stayed for seven days; Prof. Xu and Zhao Sheng, along with two seminars, had to wait two more days, so today he was alone.

To his surprise, a familiar blue pickup truck was parked outside the door.

"Mr. Zhao told me you're leaving this morning."

Catherine shook the keys in her hand and smiled lightly: "I think you'll need a car to take you to London."

"Thank you," Xu Xu Qingzhou said, accepting without protest.

They got into the car.

The engine roared to life, and the blue pickup sped toward London.

Take back what I just said—now it felt even more unreal, like my feet weren't touching the ground.

Read! {

Seeing the boy's strange, dazed expression, Song Yao couldn't help smiling—perfect effect, stunned him good.

"Meow~"

505. That's right.

At the symposium, everyone discussed the most cutting-edge topics—clashes of thought, bursts of inspiration. Attending such seminars was far superior to locking oneself in and working in isolation.

Xu Xu Qingzhou tore his gaze from his notebook and looked out the window; his thoughts drifted, beginning to consider his next task.

Just as Xu Xu Qingzhou took a few steps, Catherine's voice came from behind: "Hey, Xu, I have one last question."

When k=1, this conjecture transforms into the twin prime conjecture.

And there's Professor Maynard's idea on prime gaps—how he proved there are infinitely many pairs of primes with gaps smaller than 600, though the improvement still relied on Zhang Zhang Yitang's method, which now held no use for him.

"Goodbye."

Besides these, there were things from analytic functions—analyticity over complex domains, exploring periodicity in analytic functions, and so on.

Xu Xu Qingzhou recalled he had indeed complained about Western food being terrible, but this scene still felt dreamlike.

"Meow~"

Twin prime theorem done. Next: Polignac's conjecture.

He sent Song Yao a message saying he'd arrive in an hour, pushed his suitcase toward the airport, hailed a taxi, and headed straight for Yandongyuan Community.

Thus, at the 505 dining table, two young people began eating a strange breakfast.

Catherine said: "As an apology, you might want to look at that prime number problem I meant to ask about that day—the Irishman beat me to it."

Fuck, I can't have even gotten the building wrong? Squeak~ Just as Xu Xu Qingzhou doubted himself, the door opened again.

Song Yao nodded: "Yeah, didn't you say you wanted white rice lately?"

"I guess so."

Xu Xu Qingzhou squinted, savoring the morning sunlight, took a deep breath, and dragged his suitcase toward Building 4.

Xu Xu Qingzhou shook his head, relieved to finally be back on familiar soil—especially hearing the people around him speaking Chinese, which felt deeply comforting.

After all, the twin prime conjecture—no, now it should be called the twin prime theorem—had already been proven.

Has Song the campus beauty turned into a snail girl? Seeing the idiot still standing there, Song Yao reminded him: "Wash your hands and eat."

But challenging mathematical conjectures was just a small goal; he didn't plan to start immediately. First, finish his current physics experiment, and maybe read a few books to refresh his mind.

Unfortunately, he already had a lover.

Watching the receding figure vanish through security, Catherine's blue pupils gleamed with something unusual; she smiled faintly—he'd known exactly what she wanted to ask.

At 9:50 a. m., Xu Xu Qingzhou sent Song Yao his final message, boarded the plane, and began his journey home.

Forty minutes passed.

505.

If you're unfamiliar with the name of this conjecture, you've surely heard its special case: k=1.

With countless questions in mind, he washed his hands and went into the kitchen to help Song Yao carry out the tomato and egg soup.

"I'm sorry, I've been busy lately," Xu Xu Qingzhou said helplessly. During his time in London, he'd always felt light-headed, as if his feet never touched the ground.

"The main function of f(p) is to loosen the upper bound to c×(log p)^a."

He changed planes in Warsaw; twelve hours passed like that.

Xu Xu Qingzhou took two bites of rice, finally couldn't hold back, put down his chopsticks, and said seriously: "I have a question."

Outside the door, Xu Xu Qingzhou still smiled wryly, thinking he must be exhausted—so tired he couldn't even find his own home.

In the morning, warm sunlight fell; the tree branches had gained a touch of green, but were still mostly bare, while the gray walls reflected dappled light filtering through the branches.

With that, she waved and walked into the airport security checkpoint.

"Sorry, wrong door," Xu Xu Qingzhou blinked, snapped back to reality, apologized to the cat, and stepped out with his suitcase.

There was knowledge related to Dirichlet L-functions.

Read materials, sleep, transfer, rest, read materials, sleep. The plane landed; Beijing time: 6:10 a. m.

"What are you standing there for? Come in."

But—he looked around—it was definitely this place!

He had already proven the k=1 case of Polignac's conjecture; there was no reason not to keep researching.

"I'll remember this promise."

Huh? Their eyes met.

In Catherine's eyes glinted a mischievous triumph—she thought she'd finally gotten her petty revenge.

The conjecture states that for every natural number k, there are infinitely many prime pairs (p, p+2k).

Xu Xu Qingzhou obediently followed Song Yao inside; the tabby cat sat before its food bowl, watching him warily, as if afraid he'd steal its meal.

The sprawling cityscape shrank below; after the plane leveled out, Xu Xu Qingzhou grew bored and pulled out the notes he'd taken during the symposium. Though he hadn't attended the final two days, the earlier sessions had filled nearly half his notebook.

London Heathrow Airport.

Xu Xu Qingzhou turned to face her, smiled, and said: "Proven."

The familiar, beautiful face appeared in Xu Xu Qingzhou's vision—high ponytail, apron tied around her, hands still damp from washing them in the kitchen.

At 7:30, Xu Xu Qingzhou stepped out of the car with his suitcase.

Only when he entered the living room did he notice: several dishes were already on the table—twice-cooked pork, stir-fried seasonal vegetables—my god.

Xu Xu Qingzhou picked up the draft paper; it contained questions on the prime gap Guilv in Cramér's theorem, involving the properties and applications of the f(p) function.

The door was slightly ajar; Xu Xu Qingzhou pushed it open directly.

"Mm, goodbye."

More precisely, he was staring into the eyes of a cat.

Catherine's tone turned wistful: "Xu, I gave you my number—you never called me once."

Finally back.

Xu Xu Qingzhou exhaled deeply, glancing at Catherine with lingering shock—Zhao Sheng took an hour; she took thirty minutes. The speed was unimaginable.

!.

"Thanks for driving me—I'll treat you to a drink next time," Xu Xu Qingzhou sighed inwardly. He'd been careless. He should've known she wasn't a sweet girl the moment he realized she owned that wild pickup.

"Oh."

"Oh, okay," Xu Xu Qingzhou nodded, turned to wash his hands, then muttered: "It's morning."

"Hm?"

Song Yao nodded—she knew this would shock Xu Xu Qingzhou.

Xu Xu Qingzhou's expression turned serious: "Tell me—where did you get these dishes? From some restaurant?"

"Xu Xu Qingzhou!"

(End of chapter)