For a full two days, Lin Zhixia didn’t come to class.

Jiang Yubai’s campus life became like a faded oil painting.

Lin Zhixia’s seat was empty. Her laughter, her games during breaks, her “Human Observation Diary,” all vanished without a trace.

Lin Zhixia was recovering at home, with no news, and Jiang Yubai began to worry if something serious had happened to her. The night she developed a fever, Jiang Yubai had called her home, but no one answered.

Jiang Yubai’s parents and uncle never answered calls from strangers. Jiang Yubai suspected Lin Zhixia’s family might have similar rules.

So, that afternoon after school, Jiang Yubai decided to personally visit Ancheng Residential Area.

At five in the evening, the sky gradually darkened, the setting sun shattering the evening glow, everything dissolving into the twilight of dusk.

The main entrance to Ancheng Residential Area was wide open, with pedestrians coming and going.

The cold wind of winter whistled “shu-shu,” making people wrap their coats and scarves tighter. The streets and alleys were dim and cold, and even two streetlights were broken.

Jiang Yubai tucked both hands into his coat pockets and mingled with a group of students heading home after school, following them into Ancheng Residential Area. He easily found the Lin family’s supermarket—to his surprise, the supermarket was still open today.

Through a plastic curtain door, Jiang Yubai saw Lin Zhixia.

Lin Zhixia wore a sweater and track pants, with a pair of pink bunny slippers on her feet. She was leaning with both hands on the checkout counter, looking up at her mother and asking: “Where is my brother?”

Her mother answered: “Your brother isn’t out of school yet. At the beginning of next month, their school’s competition class will select a new batch of students. Your brother wants to test into the competition class, so he stays at school an extra half hour every day to ask the teachers questions.”

Lin Zeqiu was a student in the advanced class of the first year of junior high at Provincial No. 1 Middle School.

Provincial No. 1 Middle School was the best school in the provincial capital. It included both junior and senior high sections, gathering almost all the top students in the city and the strongest teaching resources.

The junior high section of Provincial No. 1 Middle School offered four types of classes—competition class, advanced class, regular class, and international class.

Lin Zeqiu had always wanted to join the competition class.

But he had never tested in.

“If brother wants to join the competition class, why didn’t he tell me?” Lin Zhixia asked puzzled, “I could help tutor him for the math competition.”

Mother smiled and said: “When he comes back, you can ask him.”

Lin Zhixia nodded, then said: “Mom, I want to go to University Town this weekend. Mom, can I go? Professor Shen Zhaohua has agreed to let me visit their physical oceanography laboratory.”

Before her mother could answer, Lin Zhixia glanced around and suddenly caught sight of Jiang Yubai.

Jiang Yubai and Lin Zhixia made eye contact briefly, then he bravely stepped through the supermarket door.

Lin Zhixia asked him: “Why did you come?”

Jiang Yubai had already prepared a legitimate reason for his visit. He immediately unzipped his backpack and pulled out a stack of test papers and workbooks: “Lin Zhixia, you haven’t come to class for two days, and the teacher assigned homework.”

Lin Zhixia’s mother suddenly spoke up: “Is this your classmate, Xiaxia?”

Lin Zhixia nodded proudly: “Yes! He’s my desk mate!”

After she spoke, Lin Zhixia’s father also came running out from the warehouse.

Both father and mother sized up Jiang Yubai.

Jiang Yubai stood straight. Today was his first formal meeting with Lin Zhixia’s parents. He decided to make a good impression on Lin Zhixia’s parents. His self-introduction was very detailed: “I am Jiang Yubai. This September, I transferred to Experimental Elementary School. My hobbies are reading, swimming, playing tennis, and doing math problems. I am Lin Zhixia’s desk mate this semester.”

Lin Zhixia cheerfully added: “That’s right! Jiang Yubai and I have been desk mates for four months now!”

“Four months!” Father exclaimed in amazement.

Before Jiang Yubai appeared, forget about four months, a child who could be Lin Zhixia’s desk mate for four weeks didn’t exist.

Lin Zhixia’s father had even received calls from other parents. One parent had directly advised him, saying that as Lin Zhixia’s father, he must properly control his daughter and stop her from saying all sorts of nonsense in class that affected other children.

Lin Zhixia’s father felt indignant about this.

It was clearly because that person’s child wasn’t smart enough to keep up with Xiaxia’s thinking, so how could that be Xiaxia’s fault?

And today, Lin Zhixia’s father was also hearing for the first time a nine-year-old boy claiming during his self-introduction that his “hobby is doing math problems,” which moved him somewhat. Indeed, such especially intelligent children would have a common language with Lin Zhixia.

Father asked gently: “Young classmate Jiang Yubai, did you come specially today to bring Lin Zhixia her homework?”

Lin Zhixia hadn’t come to school for two days, and the head teacher hadn’t mentioned her during class meetings.

Her home phone couldn’t be reached, which is why Jiang Yubai had thought of the idea to “pay a visit.”

The so-called “homework” was just an excuse.

Jiang Yubai was concerned about his competitor’s safety.

When he discovered that Lin Zhixia was fine, his mood lightened considerably. He went along with it and said: “Yes, I came to deliver the homework. Now that I’ve delivered it, I’ll be going. See you tomorrow, Lin Zhixia.”

By the supermarket entrance were stacked cases of drinks, shelves filled with various goods, and the floor was tiled with one light-yellow ceramic tile after another. The tiles in the corners had long since cracked, revealing several crooked gaps. The remaining fragments formed irregular patterns, looking very fragile.

Jiang Yubai paid special attention to these details. He stepped lightly on the tiles, careful not to crack another one.

He absolutely would not show disrespect in front of Lin Zhixia and her family.

Lin Zhixia suddenly called out to him: “Jiang Yubai?”

Lin Zhixia’s mother also said: “Xiaxia, get something to see him off. On such a cold day, he came from school just to bring you homework. You should remember to thank him.”

“I don’t know what he likes to eat,” Lin Zhixia was troubled.

She asked directly: “Jiang Yubai, what do you like to eat?”

Jiang Yubai had his back to Lin Zhixia. He had just stretched out a hand, about to touch the plastic curtain at the supermarket entrance. Just at that moment, two customers came from outside, a middle-aged couple returning home late from work.

Recently, Lin Zhixia’s family’s supermarket has also been selling some fruits, such as apples, bananas, oranges, pomelos, and so on. Customers stood in front of the shelves picking and choosing, and Jiang Yubai navigated around them to Lin Zhixia’s side.

Facing Lin Zhixia’s parents, he politely declined: “Thank you, Uncle and Auntie, no need to give me anything.”

Generally, when refusing others, one needs to find an appropriate reason, so as not to embarrass the other party while also saving face for oneself.

Quickly, Jiang Yubai thought of a good excuse: “Lin Zhixia at school… often inspires me to study physics. Today I brought her homework, which is just reciprocating her kindness.”

Lin Zhixia replied cheerfully: “Is that so? Then tomorrow morning, let’s discuss the overview of ‘Heterotic String Theory’ together! We can talk from the clockwise direction of nine-dimensional Grassmannian number hyperspace vibration strings to the counterclockwise direction of twenty-five-dimensional space vibration strings. Do you still remember the definitions of bosons and fermions? Quantum mechanical particles are divided into bosons and fermions. According to mathematical derivation, ten-dimensional space fermion vibrations use one way to loop, twenty-six-dimensional space boson vibrations use another way to loop, and the oriented closed strings formed by the hybridization of fermion strings and boson strings from two different high-dimensional spaces can describe gauge interactions, this is a simple description of heterotic string theory[1]. Tomorrow morning, I’ll explain it to you in more detail, more vividly, and bring along your favorite mathematical derivations.”

Jiang Yubai was startled and immediately took three steps back: “I’m going home now, see you tomorrow.”

With that, he decisively turned and left, and not even nine oxen could pull him back.

Lin Zhixia followed behind him: “Jiang Yubai, let me see you to the community entrance.”

But Jiang Yubai said: “Don’t dirty your bunny slippers.”

Lin Zhixia was wearing a pair of soft pink bunny slippers. And the city streets inevitably had dust and dirt.

Moreover, it was winter now, the night was pitch black, the moon wasn’t prominent, and the streetlights in the residential area were broken… Jiang Yubai walked down the steps, and Lin Zhixia quickly called out: “Wait for me! I’ll go home and change into a pair of sneakers! I have something I want to tell you!”

What thing?

Jiang Yubai, hampered by his curiosity, obediently stood in front of the steps, waited for about two minutes, and then Lin Zhixia came dashing toward him.

She smiled and said, “Sorry for the wait, I’m here.”

He asked: “What did you want to tell me?”

“It’s like this!” Lin Zhixia told him, “Do you remember Professor Shen Zhaohua? In mid-October, we met her and her four doctoral students at the Ocean Aquarium.”

Jiang Yubai had always suspected that Lin Zhixia would eventually skip grades.

He had never seen a girl like Lin Zhixia. When using his computer at home to surf the web, he couldn’t help but search for “childhood education of geniuses.” He discovered that intellectually superior geniuses mostly skipped grades and mostly broke conventions.

Jiang Yubai silently pondered without making a sound, while Lin Zhixia continued talking on her own: “This noon, I called one of Professor Shen’s students—that sister is called Zhu Chan, I called Zhu Chan. Zhu Chan told me that on Sunday morning, I can visit their laboratory! Do you know, Jiang Yubai, I’m so happy!”

Jiang Yubai nervously nodded once: “Is Professor Shen inviting you to attend university?”

“No,” Lin Zhixia stopped walking, “I’m only nine years old. I don’t want to go to university.”

Jiang Yubai reluctantly expressed his true thoughts: “You could go to university now.”

Lin Zhixia shook her head like a rattle drum: “I’m very free and happy just as I am now.”

Then, she also asked: “Jiang Yubai, are you free on Sunday? Professor Shen asked me to find her at University Town at nine in the morning on Sunday. If you’re free, we can visit the physical oceanography simulation laboratory together! The best laboratory in the country!”

Professor Shen worked at the best university in the province. This university is ranked in the top five nationally.

Jiang Yubai’s mathematics tutor was also an alumnus of this university.

According to Jiang Yubai’s original plan, this Sunday, he should first have a math lesson, then a piano lesson. By Sunday afternoon, his mother would host a winter banquet at home, and friends from this province and neighboring provinces would be invited to attend.

Jiang Yubai planned to postpone all his courses. As for that meaningless winter banquet, Jiang Yubai didn’t care whether he attended or not.

Lin Zhixia had already extended a sincere invitation to him. If he missed this opportunity—missed the chance to visit the university laboratory with Lin Zhixia…

He would be left far behind by his competitor.

That was certainly a scenario he didn’t want to see.

He could even predict a specific scene. For instance, Lin Zhixia might supplement in her “Human Observation Diary”: My desk mate Jiang Yubai gave up Professor Shen Zhaohua’s physical oceanography laboratory for a boring banquet. This is the thinking limitation of ordinary humans.

Jiang Yubai immersed himself in his imagination, then gave a cold laugh inwardly. Hah, he would break through the thinking limitations of ordinary humans and make the most correct, most rational choice.

After deep consideration, Jiang Yubai finally spoke: “I’m free on Sunday.”

Just five short words, concise and powerful, containing many of his plans.

Lin Zhixia immediately replied: “Great! By the way, Professor Shen said it’s best to bring a guardian, because we are both too young.”

“No problem,” Jiang Yubai promised without hesitation.

At this time, he and Lin Zhixia passed under a streetlight.

The light was almost warm orange, unable to illuminate the long winter night.

Lin Zhixia sneezed. Jiang Yubai remembered that she had a high fever the day before yesterday and had just recovered today; if she caught a cold again, it would certainly be unpleasant.

Jiang Yubai said to her, “You should hurry home, my driver is waiting for me.”

Outside the main entrance of Ancheng Residential Area, an eye-catching Aston Martin was parked. The car’s driver waved at Jiang Yubai and ran toward him.

The driver uncle was strong and ran with swift steps. He came to Jiang Yubai and wanted to take his backpack for him, but Jiang Yubai declined, so the driver said: “Let’s go, Young Master Jiang.”

Lin Zhixia chuckled softly: “Jiang Yubai, see you tomorrow?”

The night wind howled, the lights scattered. Jiang Yubai stepped forward, not looking back, thinking his profile was dashing: “See you tomorrow.”

Because Jiang Yubai had just struggled with the driver over his backpack, his coat hood was tightly caught by the backpack. The backpack hung at the back of his neck, and he was completely unaware of this. From Lin Zhixia’s angle, Jiang Yubai looked like he was wearing a turtle shell.

Although he stood with proper posture, sat with proper posture, walked with a straight spine and steady steps, he looked quite comical now, and Lin Zhixia couldn’t help but laugh secretly, as he couldn’t see or hear her anyway.

He was a very interesting person.

Lin Zhixia watched from a distance as Jiang Yubai got into the car.

She saw the car lights brighten, the wheels roll, and the black Aston Martin merge into the night, speeding forward all the way, driving toward a destination she couldn’t see.

Why did Jiang Yubai come to deliver homework?

Lin Zhixia began to ponder Jiang Yubai’s intention.

Jiang Yubai should know that Lin Zhixia writes extremely fast. It would take her only ten minutes to catch up on homework. Within ten minutes, she would complete two days’ worth of assignments.

If not to deliver homework…

Then was it because he cared about her?

That’s right!

Lin Zhixia considered Jiang Yubai a good friend, and Jiang Yubai indeed also regarded Lin Zhixia as a companion.

In the “Exploring the Universe” comic series, Lin Zhixia and Jiang Yubai would never be separated. No matter what mysterious events unfold in Orion, no matter which star system the Earth Legion chooses to settle in, Lin Zhixia and Jiang Yubai would always be companions supporting each other.

Thinking of this, Lin Zhixia’s steps back home became much lighter.

The first part of the “Exploring the Universe” comic series had already concluded. Lin Zhixia decided that tomorrow morning, she would create the second part of the “Exploring the Universe” comic series, letting Jiang Yubai understand her sincere feelings.

*

Lin Zhixia was a girl with strong initiative.

Early the next morning, she dug out her bottom-drawer notebook—this was a prize she had won at the “Elementary Student Encyclopedia Knowledge Competition” held at school last winter.

The notebook was thick, the pages smooth, flat, and non-bleeding.

Most importantly, none of the pages had grids!

Perfect for drawing!

Lin Zhixia hugged this notebook and happily ran to school for class.

Around seven-twenty in the morning, Lin Zhixia walked into the classroom of the fourth-grade 1 class, but Jiang Yubai hadn’t appeared yet.

Today’s duty students were cleaning the classroom, and the labor committee member, classmate Han Dawei, was busy running back and forth, sweating profusely. Seeing Lin Zhixia, he asked her: “Lin Zhixia, you haven’t been to class for several days, right?”

Lin Zhixia said: “Only two days.”

Han Dawei pointed to her seat: “Don’t forget to organize your drawer. Teacher Wu said that the teaching director will be inspecting the fourth-grade classrooms these days to evaluate the hygiene level of all classes. Currently, the hygiene red flag is in our class, and if the red flag is taken by another class, Teacher Wu will be furious.”

The “hygiene red flag” was a supreme honor.

At the end of each month, the teaching director would lead the brigade leader and team leaders to inspect the hygiene conditions of each class, and under the principles of fairness, justice, and openness, they would score those classes. The highest-scoring class would receive the only “hygiene red flag” in the entire grade.

The head teacher of class four grade (1), Teacher Wu, employed thunderous methods with effective management, dominating the “hygiene red flag” year after year.

It was said that the windows of class four grade (1) could reflect light, the floor was spotless, and the blackboard was cleaner than the labor committee member’s hair in other classes.

Teacher Wu explicitly required that all students maintain desktop cleanliness, preferably by wiping their desks every day.

Lin Zhixia hadn’t been to school for two days, but her desktop remained neat.

She knew that Jiang Yubai had also helped tidy her desk these two days.

She put down her backpack, opened her pencil case, and wrote on the notebook cover: “Exploring the Universe” Comic Series Part Two.

After Lin Zhixia finished writing, she immediately looked around to ensure no one had discovered her actions. Through a clean glass window, she happened to see Jiang Yubai crossing the corridor. He carried his backpack and entered the front door of the fourth-grade 1 classroom.

Jiang Yubai’s first words after sitting down were: “I have an uncle, he’s my father’s younger brother. On Sunday morning, he will take me to University Town.”

“Great! In just two more days, we can visit the university laboratory together!” Lin Zhixia chatted with Jiang Yubai while drawing her comic.

Jiang Yubai noticed that Lin Zhixia was compiling another plot for “Exploring the Universe.”

Lin Zhixia smoothed the first page of the notebook and set the title “Exploring the Universe Part Two Prologue: Survival Miracle in the Age of War.”

In front of Jiang Yubai, she straightforwardly wrote: After the Orion base was destroyed by evil forces, the Earth Legion drifted through the universe searching for their next target. The massive losses brought by war made all team members understand the importance of peace…

Jiang Yubai provided a new plot direction: “Lin Zhixia made a major discovery near Orion.”

Lin Zhixia nodded and recorded: A red supergiant star named Betelgeuse caught the attention of Jiang Yubai and Lin Zhixia. Betelgeuse is accelerating its expansion, it’s about to explode!

Jiang Yubai became a bit anxious: “Betelgeuse is about to explode, isn’t Lin Zhixia going to escape?”

“No escape,” Lin Zhixia claimed, “Betelgeuse is a star in Orion. Stars in their late evolutionary stages undergo super explosions, producing intense electromagnetic radiation, emitting the brightest light, illuminating the entire Orion. Then, it will become a supernova! Lin Zhixia wants to observe the formation process of a supernova.”

Jiang Yubai took out his fountain pen from his backpack and wrote in a blank space of Lin Zhixia’s notebook: Won’t the strong electromagnetic radiation ignite the molecular cloud cores? Jiang Yubai wants to take Lin Zhixia to escape.

Lin Zhixia laughed “hahaha.”

She quietly exclaimed: “Jiang Yubai, when I play games with you, I feel very happy.”

Jiang Yubai gripped his fountain pen and wrote: I am a bit happy too.

When writing, he hadn’t had time to think thoroughly.

After writing those six characters, he suddenly realized… what had he written!

Continuing like this, he might lose his competitive spirit. Lin Zhixia would treat him as a regular friend, just like how she viewed Gan Shuli, Ding Yan, and Dong Sunqi.

Wouldn’t he then forever lose to Lin Zhixia?

He absolutely wouldn’t allow that to happen.

While Jiang Yubai was distracted, Lin Zhixia added physics formulas beneath the diagram of the “Betelgeuse” star. She wrote: The formula for saturated nucleon pressure at the zero temperature limit substituted into the supernova explosion equation of state can be used to calculate the gravitational collapse and shock wave propagation[2].

Then, Lin Zhixia read out the next plot: “After calculation, Jiang Yubai discovered that his spaceship needed to develop to the level of ‘spatial leaping’…”

Lin Zhixia hadn’t finished writing when Jiang Yubai pointed out an issue: “In this chapter’s comic, Jiang Yubai calculated the gravity and shock wave?”

“Yes,” Lin Zhixia nodded repeatedly.

Jiang Yubai took a deep breath and mercilessly criticized himself: “Wrong! How could Jiang Yubai possibly calculate that?”

“Of course Jiang Yubai can!” Lin Zhixia turned to him with a smile, “Because Jiang Yubai is also very capable! Jiang Yubai is super capable!”

A “boom” sounded in Jiang Yubai’s mind, as if something had exploded.

This was the first time he had heard Lin Zhixia say with his ears: Jiang Yubai is also very capable! Jiang Yubai is super capable!

He capped his fountain pen and suddenly laid his head on the desk, burying his entire face in the crook of his arm.

He wore a well-made loose coat, the sleeves covering the side of his face. Lin Zhixia couldn’t see his expression, only noticing that his ears had turned bright red.