Bai Muwan had a dream.
In it, she stood in a very, very long hallway. The walls on either side were white—blindingly white. At the end of the hall was a door, warm yellow light spilling through the crack beneath it, like the lamp in the old house's living room.
She walked forward for a long time, but the door only grew farther away.
Then she heard her mother's voice.
“Wanwan, stop going forward.”
She turned around. The hallway was empty. There was nothing there.
“Mom?”
No one answered.
When she woke up, her pillow was wet.
Bai Muwan lay there in a daze for a few seconds, then reached up and touched her face. Sure enough, she had been crying. She rolled over and buried her face in the rabbit plushie named Nuo Mi, sniffling into it.
Nuo Mi's ears had already gotten fuzzy from all the rubbing, and the stitching on its belly had been repaired twice, but she couldn't bear to replace it. Her mother had given it to her for her last birthday. She had been eighteen that year, and her mother had smiled and said, “Our Wanwan will always be a little kid, so you still need to sleep hugging a bunny.”
Three months later, her mother was gone.
Her phone buzzed.
Bai Muwan stuck one hand out of the covers and fumbled around for a long time before finally finding her phone. The screen lit up. It was a message from her big brother.
“Class today?”
Just two words. No good morning, no emoji, not even punctuation beyond a question mark. But Bai Muwan smiled when she saw it, because her big brother taking the initiative to text was incredibly rare.
She typed a long reply: “I do~ Computer science at ten this morning, law at two this afternoon~ Are you on duty today, big brother?”
She sent it.
Thirty seconds later, a reply came.
“Mm.”
Bai Muwan stared at that one syllable for a while, then typed, “What time did you go to bed last night, big brother?”
This time, she waited a long while. Long enough that she thought he wasn't going to answer.
Then the screen lit up.
“Leave early. Don’t be late.”
He hadn't answered her question.
Bai Muwan set down her phone and stared blankly at the ceiling. She remembered falling asleep on the living room sofa after the family dinner on Sunday because she had eaten too much. When she woke in the middle of the night to use the bathroom, she passed by her big brother's study. The door wasn't fully closed, and the light inside was still on.
She had been about to push the door open and ask why he was still awake, but the sight through the crack made her stop.
Her big brother sat at the desk, a stack of papers spread out in front of him. They weren't the case files he usually worked with, but old, yellowed papers with curled edges. His hand pressed down on one of them, his knuckles faintly white, as if he were using a great deal of force.
Bai Muwan had never seen that expression on him before.
It wasn't his usual sternness or his cold hardness. It was something—she couldn't find the words to describe it—like someone standing at the edge of a cliff, staring down for a long time, then deciding to take one step back.
That kind of expression.
She didn't open the door. She quietly returned to her room, lay in bed with her eyes open, and heard the light in her big brother's study stay on until four in the morning.
She knew because she hadn't slept either.
By the time Bai Muwan reached school, she was three minutes away from being late.
She ran into the classroom. Before she could even put down her backpack, her foot caught on a desk leg, sending her pitching forward. Luckily, a classmate in the row ahead reached out and caught her.
“Bai Muwan, every time you enter the classroom, it's like you're starring in an action movie.” Her roommate, Lin Kelan, had already saved her a seat. She handed Bai Muwan some water and shook her head.
“I actually left early today!” Bai Muwan gasped as she sat down, pushing her bird's-nest hair back. “But while I was waiting for the bus, I saw a stray cat. It looked like it was hurt, so I—”
“So you crouched there and talked to the cat for twenty minutes.”
“…Fifteen.”
“Does that make a difference?”
Bai Muwan smiled sheepishly and dug her textbook out of her backpack. After rummaging around for ages, she pulled out an orange, a pack of tissues, a tube of lipstick—big sis had forced it on her—three mints, and an autographed photo of her fourth brother, which she had no idea when someone had slipped in. Finally, she found her textbook at the very bottom.
A note was tucked inside, written in her second brother's handwriting: “It's getting colder today. Wear another layer. There's honey water in the fridge. Remember to bring it.”
She hadn't brought the honey water. She had even forgotten to wear another layer.
Bai Muwan carefully tucked the note back into the textbook. Her heart felt warm, along with a tiny bit of guilt.
Her computer engineering class was Advanced Programming, and today's lecture covered encryption algorithms. Bai Muwan actually loved the class. All the intelligence in her head that was completely useless in everyday life finally had a place in the world of code. She could forget her umbrella, forget her keys, and mistake salt for sugar, but none of the programs she wrote ever had a bug.
The professor was explaining the mathematical principles behind RSA encryption. Bai Muwan's notes flew across the page, messy but logically clear. She even drew a small flowchart in the margin and worked out the part the professor hadn't covered yet on her own.
Lin Kelan sneaked a glance at her notes and silently mouthed, “Freak.”
Bai Muwan didn't notice. She was staring at a piece of sample code on the screen, her brows drawing together slightly.
There was a hidden logic flaw in the code. The professor hadn't mentioned it, probably because he had left it for the students to discover themselves. But Bai Muwan found it in three seconds—not because she had been looking for it, but because the flaw was so obvious to her, like an ink stain on a white shirt.
She raised her hand.
“Professor, shouldn't the loop condition on line seventeen be changed to a strict less-than? As it's written now, when the input value is exactly equal to the boundary, it will run one extra iteration and the encryption result will be wrong.”
The classroom fell silent for two seconds.
The professor pushed up his glasses and glanced at her, the corners of his mouth lifting slightly.
“Miss Bai, I've hidden that flaw for three years. You're the first student to point it out directly in class.”
A wave of quiet astonishment swept through the room. Bai Muwan froze for a moment, then her face went bright red.
“I—I didn't do it on purpose… I just thought that part looked kind of weird…”
Lin Kelan whispered beside her, “You're a genius idiot.”
Bai Muwan buried her face in her textbook, her ears red as boiled shrimp.
After class, Bai Muwan hugged her textbook and headed toward the law school. The two colleges were on opposite sides of campus, so she had to cross an entire avenue of ginkgo trees. By December, most of the ginkgo leaves had already fallen, covering the ground in a golden-yellow carpet that rustled beneath her feet.
She walked very slowly because she was carefully stepping on the lines between the paving stones. Left foot on a line, right foot on a line. She couldn't miss a single step. It was a habit she'd had since childhood. She couldn't break it, and she'd never wanted to.
When she reached the middle of the ginkgo avenue, her phone rang.
It was her third brother.
“Hello?”
“Idiot, you forgot your coat again, didn't you?”
Bai Muwan looked down at herself. She was wearing a thin sweatshirt, flimsy as a sheet of paper in the December wind.
“…I brought one.”
“Your voice gets higher when you lie. It's been that way your whole life.”
“There’s a coat in the locker by the school gate. The combination is your birthday. I just put it there.”
Bai Muwan opened and closed her mouth. “Third brother, how did you—aren't you in class at school? It takes forty minutes to drive from your school to mine—”
“I was in the area.”
“How is your school anywhere near mine? It's completely the opposite direction!”
“I said I was in the area.” Her third brother's tone left no room for argument, but there was a hint of laughter in his voice. “Put it on, or I'll tell big brother.”
The call ended.
Bai Muwan stood on the ginkgo avenue with her phone pressed to her ear, the wind whipping her hair into a mess.
She sniffed. It wasn't because she was cold.
She turned and ran toward the school gate to get the coat.
At nine that evening, Bai Muwan was writing her law report in the library.
Five books, three case precedents, two cups of completely cold milk tea—bought by Lin Kelan—and a half-finished report were spread out in front of her. The topic was “The Admissibility Standards for Digital Evidence in Criminal Proceedings.” She had chosen it because she thought the intersection of computer science and law was interesting, but halfway through, she realized she had dug herself an enormous hole.
She slumped over the table, her cheek pressed to the open law code, and let out a muffled groan.
Her phone buzzed again.
A message in the family group chat.
Her fourth brother posted a selfie from the set. He was still in costume and hadn't removed his makeup yet. The caption read: “Missing my little sis. Filming was so exhausting today. I need my sister's encouragement to survive QQ.”
Big sis replied instantly: “Your makeup makes you look like a ghost.”
Fourth brother: “It's required for the plot! I'm playing a general!”
Big sis: “A ghost general.”
Third brother: “HAHAHAHAHAHAHAHA.”
Second sister sent a “…” reaction.
Second brother: “Wrap early. Get some rest.”
Fourth brother: “Only second brother loves me QQ.”
Bai Muwan smiled and typed, “Fourth brother, you look so handsome! You've got this! Today's fourth brother is the best too!” She added twelve heart emojis.
Fourth brother instantly replied with twenty-four hug GIFs.
Big brother wasn't in the family group chat.
Bai Muwan scrolled up through the chat history. Her big brother hadn't said a word in the group chat all day. That wasn't normal. He didn't talk much, but he usually asked “Has everyone eaten?” around dinnertime, or sent “Go to bed early” late at night.
Today, there had been nothing.
She opened her private chat with her big brother. Their conversation was still stuck on his morning message: “Leave early. Don't be late.”
She hesitated, then typed, “Big brother, did you eat dinner?”
She sent it.
Ten minutes passed with no reply.
Bai Muwan bit her lip and typed another message: “Big brother, the professor praised me in class today! He said I'm the first student in three years to find the bug in the code! Wasn't that impressive?”
She sent it.
Another five minutes passed.
A reply came.
“Impressive. Come home early.”
Four words. But Bai Muwan stared at “Impressive” for a long time, the corners of her mouth slowly lifting.
Her big brother had said she was impressive.
Her big brother rarely praised anyone.
Content, she set down her phone and continued writing her report. The wind outside grew stronger and stronger, making the library windows tremble faintly. She pulled the coat her third brother had brought her tighter around herself. It was huge, a men's coat, with sleeves that extended past her hands, but it was very warm.
She didn't notice the dark gray car sitting silently in a corner of the parking lot across from the library, beyond the reach of the streetlamp.
The man inside lowered his phone.
The screen displayed a photograph: Bai Muwan's profile as she lay over the library table, photographed through the glass. It was somewhat blurry, but the ginkgo leaf stuck to her sweatshirt was clearly visible.
The photograph was sent to an encrypted channel.
A line of text followed: “Target confirmed. Mu Baiyuan's youngest daughter, Bai Muwan, twenty-two years old, senior, double major in computer science and law. Currently residing at—”
Before the message was finished, another encrypted message popped up.
“Don't touch her.”
The sender's codename was a string of gibberish, but the man in the car clearly recognized it. His finger rested on the screen. After hesitating for three seconds, he deleted the photograph.
He started the engine and drove silently out of the parking lot.
Inside the library, Bai Muwan let out a huge yawn and buried her face in the coat's collar. It smelled faintly of laboratory disinfectant—the scent of her third brother.
She smiled and continued writing her report.
The wind outside grew colder and colder.