Lin Zhixia dragged over a chair and placed it beside Lin Zeqiu. She took a sheet of paper with her left hand and picked up a ballpoint pen with her right. She quickly wrote down the solution process, explaining as she wrote, “Brother, first draw an auxiliary line, which gives you two similar triangles, then draw a perpendicular line. According to the circle’s perpendicular diameter theorem, you can derive an equation…”

Lin Zeqiu’s blocked thought process suddenly opened up. He grabbed Lin Zhixia’s hand, stopping her from writing further, and said, “I’ve figured it out.”

Lin Zhixia asked, “What about the second-to-last problem, brother? Can you solve it now?”

No, he couldn’t.

Lin Zeqiu had only figured out the second-to-last problem. As for the final problem, it remained beyond his capabilities.

Yet his sister asked him with an expectant tone whether he could now solve the last problem.

Lin Zeqiu felt extremely dejected, his mind becoming somewhat dazed. He turned his head slightly and gazed at Lin Zhixia.

Lin Zhixia stared at him with bright eyes. It was obvious that she cared deeply about her brother’s academic progress. She had placed her stuffed penguin toy on her lap. When she wasn’t writing, she would hold the penguin with both hands, making it take off and land.

How childish.

Her entertainment activities were truly childish.

Even though Lin Zhixia was a dedicated and responsible math teacher, Lin Zeqiu still found it difficult to accept the fact that “I need her tutoring.” He was almost fifteen years old; why did he need a little girl who couldn’t part with her stuffed penguin toy to teach him how to solve challenging problems?

He took a deep breath and told a lie: “I know how to do the last problem. You can go back to your room for your nap.”

“Really?” Lin Zhixia said, “Brother, write out the solution process. Once you’re done, I’ll go to sleep.”

Her brother suddenly questioned her: “Can you put away your little penguin?”

Lin Zhixia’s curled, black eyelashes fluttered lightly: “Why?”

Her brother said: “Because…” He struggled for a while before finally squeezing out: “I hate penguins.”

Lin Zhixia hugged her little penguin tightly. She was full of confusion: “Why do you hate penguins? Have you been to Antarctica? I could only believe you if you had been to Antarctica and been bitten by a penguin.”

Her brother irritably ran his fingers through his hair. The heavy household chores had built up his physical fitness, giving his arms smooth, defined lines. He should have been an energetic, healthy teenager, but instead he claimed: “I’ve had many nightmares, understand?”

Lin Zhixia hid the little penguin behind her back: “Brother, have you had many penguin-related nightmares? In your previous life, were you perhaps a fish in the Antarctic Ocean…”

Her brother remained silent.

Lin Zhixia hurried back to her room and hid her little penguin under her blanket. She said to the stuffed toy: “I’m sorry, from now on we can only be together secretly. I’ll try my best not to let my brother see you.”

When she was talking to her little penguin, Lin Zeqiu happened to be standing at the doorway.

Hearing his sister’s words, Lin Zeqiu felt like banging his head against the wall. He just couldn’t accept being tutored by his younger sister; he wasn’t some coward afraid of stuffed toys!

If this got out at school, how could Lin Zeqiu save face?

In their Class 3(4), his light had already been overshadowed by Lin Zhixia. People often came to interview him, asking about Lin Zhixia’s study methods. He would always rudely reply: Don’t bother me, I don’t know.

His classmates would then realize: Of course, if you knew, you would have made it into the competition class long ago.

Such scenes played out almost weekly.

Lin Zeqiu sorted through his thoughts and composed himself. He stepped forward and knocked on Lin Zhixia’s door. When Lin Zhixia turned and saw him, she immediately grabbed her blanket to cover the little penguin completely, then took out her pillow and placed it over the blanket.

Lin Zeqiu tasted the bitter flavor of being misunderstood. He really couldn’t solve the final problem and couldn’t possibly ask Lin Zhixia for help again. He wanted to walk around the house, clear his mind, adjust his state, and then go back to continue working on the problem.

He urged Lin Zhixia: “What are you dawdling for? Hurry up and take your nap.”

Lin Zhixia crawled under the blanket: “Brother, if you feel tired, you can rest too. This morning, Mom aired out our blankets for us. The blankets are nice and warm. Lying in bed to sleep at this time is comfortable. Brother, why don’t you go back to your room and try it?”

The person who aired the blankets wasn’t Mom, but Lin Zeqiu.

At seven o’clock this morning, while Lin Zhixia was still brushing her teeth and washing her face in the bathroom, the sunlight outside was pure and brilliant. Lin Zeqiu set up an iron rack on the balcony, wrung out a clean, damp cloth, and carefully wiped down the horizontal bars of the rack.

The balcony was narrow, and the rack wasn’t long enough. He could only air two quilts at a time. Lin Zeqiu thought for a moment, then brought out Lin Zhixia’s quilt first, followed by the quilt from their parents’ bedroom. He gave them priority for sun-drying.

Besides airing the quilts, there were many other chores, but he couldn’t remember them all. He didn’t have Lin Zhixia’s memory.

Lin Zhixia was good at getting her way, acting well-behaved, speaking sweetly, and couldn’t be wronged. With her pretty and cute appearance, she was like a little angel descended from heaven. It was inevitable that their mother favored her more.

Lin Zeqiu felt he could understand this.

He glanced at the wall clock and said to Lin Zhixia: “Hey, you can still sleep for forty minutes. When it’s time, I’ll wake you up.”

“Mm-hmm, thank you, brother!” Lin Zhixia responded.

Lin Zeqiu closed his sister’s door. He went to the kitchen, opened the refrigerator, his fingertips passing over strawberry yogurt, and picked up a box of peach yogurt. He lifted the lid just as his mother was changing shoes at the entrance. He asked, “Mom, are you going out?”

His mother told him with a beaming smile, “I’m going to the market to buy fresh shrimp. I’ll get a few extra pounds, prepare the filling, and make shrimp dumplings. Qiuqiu, what would you like to eat tonight? I’ll buy it while I’m out.”

Lin Zeqiu paused for a moment, then said: “I’d like apples.”

“Besides apples?” His mother held the doorknob. “How about green peppers with beef? You always enjoy that dish.”

Lin Zeqiu casually said, “Forget it, that two thousand yuan is Lin Zhixia’s scholarship money. Just buy more of what she likes to eat.”

His mother paused in her steps: “You are Xiaxia’s brother. She would certainly be willing to share with you. Xiaxia is Mom’s good child, and Qiuqiu is also Mom’s good child.”

When his mother said these words, Lin Zeqiu was tilting his head back to gulp down the yogurt. He coughed once, about to say something, but his mother had already left. He rushed to the door and saw his mother pushing out a bicycle—the seat of his mother’s bicycle had been broken for a long time. Yet Lin Zeqiu’s bicycle was still in perfect condition. Even so, his mother had never borrowed Lin Zeqiu’s bike.

Lin Zeqiu unconsciously called out: “Mom.”

His mother instructed him: “Tonight, we’ll have shrimp dumplings, stir-fried beef with green peppers, apple compote, cold tofu salad, and a plate of green vegetables. You like cola, and I’ve just put a can in the refrigerator to chill for you… After school, bring your sister home, and our family will have a good dinner together.”

Lin Zeqiu stood up straight. His spine was as straight as a plumb line. He gripped the door handle, his voice humming indistinctly: “Okay.”

Lin Zhixia also liked to say “okay.” She could make those two short syllables sound sweet, full of vitality, and likable. But when Lin Zeqiu expressed the same acknowledgment, it was as if his mouth contained a rotten peach. His mother waved at him once and rode away from the apartment building.

Lin Zeqiu suddenly felt a renewed sense of strength. The math problem that had been troubling him earlier didn’t seem quite so terrifying anymore. He closed the door, returned to his bedroom, and threw himself into his studies with renewed vigor.

Unfortunately, his mental strength was only like a flash in the pan.

After another ten minutes, he still couldn’t solve the final problem.

Time ticked away second by second, and he sat on the chair like he was on pins and needles.

The peach yogurt cup was covered with a thin layer of tiny water droplets, like beads of sweat flowing from his heart. He held the yogurt cup, his fingers dampened by the moisture, feeling slightly cool. He lifted his chin, his gaze penetrating the glass window, when Lin Zhixia’s voice came from behind: “Brother…”

He was startled: “Why are you awake?”

Lin Zhixia rubbed her eyes: “I dreamed that you were eaten by a little penguin. I was crying sadly in my dream…”

Lin Zeqiu felt very awkward.

But he couldn’t contradict what he had told his sister. He vaguely responded: “It was just a dream. What are you afraid of?”

Lin Zhixia insisted righteously: “I’m just a little scared, is that not allowed?”

There was another chair beside Lin Zeqiu. He patted the empty seat firmly, and Lin Zhixia ran over with a “pitter-patter” and sat beside him. He raised his hand and stroked her head as if petting a kitten.

“You’re too timid,” Lin Zeqiu criticized her while smoothing her hair.

But Lin Zhixia said: “But I’m not afraid of penguins or insects.”

When Lin Zeqiu was little, he had been bitten by a centipede, and since then, he had developed a fatal flaw. Whenever he saw insects, he would completely fall apart, abandoning all his masculinity, unable to maintain his usual proud, calm, and aloof demeanor.

He warned Lin Zhixia: “Don’t mention insects in front of me. If you mention them one more time, I’ll immediately tell you ghost stories.”

Lin Zhixia was terrified of ghost stories. She couldn’t forget them, nor could she forget the horrifying atmosphere they created. At her brother’s casual remark, her face went pale. She complained indignantly: “You’re so mean.”

Her brother slowly and gently stroked her head once more: “Ungrateful brat.” He said: “Since you were three years old, Mom and Dad have asked me to help take care of you. I was only six that year.”

Lin Zhixia stopped talking.

The glass window faintly reflected the indoor scene. The siblings were getting along harmoniously, warm familial affection flowing abundantly—what a touching scene it was.

Until Lin Zhixia spoke up: “Brother, you still haven’t solved the final problem?”

Lin Zeqiu withdrew his hand, stood up, and organized his pencil case: “It’s almost time. Go get ready, and we’ll head out to school.”

Lin Zhixia ignored her brother. She picked up her pen and wrote out the answer on paper, with extremely detailed solution steps. She even took out a blank sheet and carefully summarized the “approach to solving similar problem types.” After writing the last word, she yawned and quietly returned to her room.

Lin Zeqiu held the pages she had left behind, standing motionless for a long time.

That evening, Lin Zeqiu again benefited from Lin Zhixia’s achievement. Their family dinner was as sumptuous as a New Year’s Eve feast.

Business was busiest between six and seven in the evening, and their father didn’t dare to pause operations, so he packed some dishes in a lunch box. Lin Zhixia picked up her chopsticks, grabbed her father’s lunch box, and scooped a large portion of shrimp dumplings and green pepper beef into it.

Their father was immediately filled with emotion: “How good Xiaxia is! Tell me, my Xiaxia, what a wonderful little girl.”

He held the lunch box, satisfied, and walked toward their family store.

Their mother remained at the dining table, accompanying her son and daughter for dinner. Lin Zhixia expressed her happiness by clapping: “Shrimp dumplings! Three plates of dumplings!”

Their mother smiled and said: “If you like them, eat more.”

Lin Zhixia held her porcelain bowl, poured in vinegar, and reverently picked up a shrimp dumpling and placed it in her bowl. She savored the chewy skin, tender shrimp, sweet corn, and the sour, delicious aged vinegar with slow, deliberate bites. Her heart and lungs were filled with joyful emotions, and even the air she breathed became light and sweet.

“Xiaxia is very happy,” Lin Zhixia ate enthusiastically.

After eating seven dumplings in a row, she asked: “Are brother and mother happy too?”

Her mother coaxed her: “When Xiaxia is happy, Mother is happy.”

Lin Zhixia received a satisfactory answer from her mother. She turned her head to look at her brother.

Her brother hadn’t dipped anything in vinegar, simply placing green pepper beef and shrimp dumplings in his bowl, devouring the delicious food like a whirlwind. To his left was a bowl of apple compote, and to his right was a glass of ice-cold cola. He could barely keep up with all the food. Hearing Lin Zhixia’s question, he surprisingly said: “Thanks to you, our family has an extra two thousand yuan.”

When Lin Zhixia won the first prize in the junior high school competition, the school had rewarded her with a five-hundred-yuan scholarship. But she hadn’t handed over that five hundred yuan. She had secretly hidden it—this way, when she needed to buy books, stationery, or participate in spring and autumn school trips, she wouldn’t have to ask her parents for money. She always felt a bit embarrassed when asking her parents for money.

When her brother mentioned the “two thousand yuan,” it reminded Lin Zhixia of her five hundred yuan. Her face reddened, and she bit into a dumpling, speaking evasively: “Two thousand yuan isn’t a lot of money… I’ll earn more in the future.”

Her brother, as if trying to compete with her, quickly added: “I can earn a lot of money too.”

“After you earn money, you have to treat me to a meal,” Lin Zhixia proposed one of her dreams, “I want to eat Atlantic lobster with Mom, Dad, and brother.”

She gestured a length: “An Atlantic lobster this big.”

Her brother gripped his cola bottle: “There will be such a day.”

Lin Zhixia nodded: “Yes, there will be.”

*

Lin Zhixia loved seafood.

She had once carefully read a book called “The Complete Guide to Marine Life” in the library to determine which seafood was edible and which was not. Later, when she became deskmates with Jiang Yubai, she learned even more seafood-related knowledge from him.

Jiang Yubai had extremely broad knowledge. Not only had he read many books, but he had also personally traveled to various parts of the world. His own experiences and descriptions were far richer than the perspectives offered in “The Complete World Travel Guide.”

Lin Zhixia enjoyed listening to him recount what he had seen and heard during his travels.

She had heard him talk about St. Paul’s Cathedral in London, England. On the lower level of St. Paul’s Cathedral, the Duke of Wellington’s coffin was stored. Faded flags hung around the coffin, and the names of the deceased were carved into the stone floor.

Departing from St. Paul’s Cathedral, it was only a ten-minute drive to reach the famous “London Eye.”

However, Jiang Yubai said that the “London Eye” wasn’t interesting at all; it was a very boring attraction. He stood on a bridge near the “London Eye,” watching tourists take boat tours of the Thames River from a distance…

“What’s the Thames River like?” Lin Zhixia asked him.

He hesitated for two seconds, then honestly said: “The water color is yellowish, rather murky, not very clean.”

Jiang Yubai was very particular about cleanliness, and his focus differed from Lin Zhixia’s. Lin Zhixia cupped her face with both hands and concluded: “So that’s what London’s Thames River is like. Indeed, industrial pollution is too severe. I’ve seen it in books.”

Jiang Yubai added: “The upstream part of the Thames is still okay. There’s a Hampton Court Palace to the north of London, on the upstream riverbank, and the scenery there is decent. Many famous buildings are constructed along riverbanks. The Cherwell is a tributary, with Oxford University beside it…”

Lin Zhixia suddenly asked again: “What about Paris, France? What is Paris, France, like?”

Jiang Yubai picked up his water cup and patiently narrated his sightseeing journey. Lin Zhixia felt as if she had set off with him and admired foreign landscapes. What made Jiang Yubai interesting was that he shared completely unembellished personal experiences.

He said that on the summit of the Alps in July, the swirling heavy snow turned his hat white. In August in Aswan, Egypt, the sunshine around the Abu Simbel Temple was so intense that he couldn’t keep his eyes open. He admired how the ancient Egyptians built world wonders under such harsh conditions.

After listening to his travel introductions, Lin Zhixia immediately resolved: “I will tell you about my experiences too.”

Jiang Yubai asked her: “What experiences?”

If it had been someone else asking Jiang Yubai about his travel stories, he would have certainly refused to answer. But Lin Zhixia was different. Jiang Yubai knew that Lin Zhixia stayed at home every winter and summer vacation, hardly ever going out to play. Out of a sense of compensation, he spoke to her without reservation, holding nothing back.

In return, Lin Zhixia said: “Next January, I’m going to participate in the 2007 National Olympic Mathematics Competition. The students and teachers from our provincial team will all stay in a hotel. Can I call you then? I want to share my national competition experience with you.”

“Of course,” Jiang Yubai agreed without hesitation.

He wrote down his mobile number, his bedroom landline number, and even the mobile numbers of his driver and housekeeper, perfectly ensuring smooth communication between him and Lin Zhixia.

Lin Zhixia glanced at the note and said: “I’ve memorized it.”

Jiang Yubai couldn’t join Lin Zhixia for the 2007 National Olympic Mathematics Competition, which left Lin Zhixia somewhat regretful. But, as Jiang Yubai said, Lin Zhixia needed to bravely move forward and explore new universes.

*

On January 25, 2007, Lin Zhixia, along with her provincial team, arrived in the city hosting the National Olympic Mathematics Competition. This was the first time in her life that she had traveled far from home alone, without her father, mother, or brother by her side.

At night, Lin Zhixia lay quietly on the hotel bed, hugging her stuffed penguin.

The hotel room was immersed in boundless darkness. Thick curtains blocked out all light sources, and the moon was invisible tonight. Lin Zhixia opened her eyes wide, staring at the pitch-black ceiling. She could hear her heartbeat—thump-thump, seemingly right beside her ears.

She hugged her little penguin tightly, afraid and shrinking into the blanket.

All her life, she had been particularly afraid of unfamiliar dark environments.

Lin Zhixia tossed and turned, unable to fall asleep. She deeply regretted not insisting that her mother accompany her to the competition. She had worried that after her mother left, her father wouldn’t be able to manage everything at home by himself, so she had confidently declared: All students in the provincial team are minors, Lin Zhixia won’t encounter any problems! Lin Zhixia is strong and brave!

Lin Zhixia felt extremely ashamed.

She wasn’t strong at all, nor was she brave.

In the silent hotel room, her nerves were taut, but the feeling of fear didn’t dissipate; it remained deeply rooted in her gut. She recalled ghost stories that she had heard adults tell in the countryside when she was little. It was said that at the dead of night, if a ghost appeared behind a person, they absolutely must not look back, but could only slowly turn around; otherwise, the person would be scared to death by the ghost.

Lin Zhixia recalled the atmosphere at that time, the cold of the winter night, her grandmother’s solemn expression—she almost frightened herself out of her wits.

She also remembered that one afternoon, she had a dream where the little penguin had eaten her brother. Thus, even the little penguin in her arms could no longer provide Lin Zhixia with any sense of security. She missed Jiang Yubai terribly. Jiang Yubai always pretended to be calm and composed; he would run to the playground during breaks and hang from the horizontal bar; he would quietly open his thermos and drink water when classmates around were discussing him. He would gently push her back when she was too afraid to take a step forward.

Lin Zhixia wanted to call him.

The current time was nine-oh-five at night.

Jiang Yubai was already asleep. He would go to bed at eight-thirty every night. He needed to grow taller, and she couldn’t disturb him.

Lin Zhixia passed this night in a daze. At two in the morning, half-asleep and half-awake, she inadvertently glimpsed the red light of the TV’s power indicator and was startled again. She completely crawled under the blanket, covering her toes and hands with the blanket, leaving only the lower half of her face exposed to breathe.

The next morning, when Lin Zhixia got up, her head was fuzzy.

After washing up and making some preparations, Lin Zhixia followed her teachers and classmates to the designated location to attend the opening ceremony of the 22nd National Middle School Students Mathematics Olympiad. She met mathematics competition experts from all over the country, and even overseas students from Russia, Singapore, and other regions participating in the competition.

The competition was so intense!

Lin Zhixia felt that she needed a good night’s sleep tonight to perform at her best in tomorrow morning’s competition test.

That afternoon, around five or six o’clock, Lin Zhixia first called her mother. Her mother comforted her for half an hour, making her feel relieved, and she immediately called Jiang Yubai afterward.

Since Lin Zhixia had left with the provincial team, Jiang Yubai’s adjacent seat had remained empty. During these two days, Jiang Yubai carried his mobile phone with him at all times, even placing it on the bedside table when he slept at night. He had intentionally and unintentionally reminded the housekeeper and driver to pay attention to unfamiliar calls, but still hadn’t received any news from Lin Zhixia. Just as he was puzzling over this, finally, Lin Zhixia’s call came through.

His phone kept vibrating while he was having dinner.

He put down his chopsticks and immediately pressed the answer button. Lin Zhixia’s voice rang in his ear: “Jiang Yubai, Jiang Yubai, the exam starts tomorrow. This morning, I saw students from various provinces at the opening ceremony… I didn’t sleep well last night. The room was too dark, I was a bit scared. It would have been better if you could have attended the competition with me.”

“Even if I competed with you, we wouldn’t share a room,” Jiang Yubai analyzed rationally.

Jiang Yubai’s father, mother, and uncle were all at the dinner table. Hearing his nephew’s words, his uncle immediately spat out a mouthful of wine.

Jiang Yubai didn’t quite understand. What he said was correct; why did his uncle react so strongly? He continued to comfort Lin Zhixia: “Don’t be afraid, Captain Lin Zhixia. The universe is black; are you afraid of the universe?”

“No, I’m not,” Lin Zhixia answered honestly.

Jiang Yubai nodded: “Captain Lin Zhixia, set forth toward the universe.”

Lin Zhixia’s fighting spirit blazed up: “Alright!”