In the lab, Song Ping hadn’t left after work, waiting for Wen Xining to finish the report.
It was just a piece of paper, and with modern technology, there were numerous testing methods. However, due to its strong absorbency, Wen Xining was very cautious with the solution test to avoid accidentally destroying the only evidence.
Soon, the secret of the paper was revealed—below the pen-written text appeared some marks, written with water starch, a kind of invisible ink that dried clear but revealed its true form with iodine tincture.
“This is…” Wen Xining picked up the paper with tweezers and observed it against the light, “Matrix code? What are the two symbols after that? An inverted V? An R? What kind of puzzle is this?”
“It looks like a mix of math and English, hard to decipher,” Song Ping looked at the transparent glass, “Maybe the guy outside knows.”
“You’ve been dazzled by him; this is nothing to him.” Wen Xining put down the paper and placed the tweezers in an empty beaker, “Just wait a bit; I’ll run a spectrum test and get a report out. Then you can go solve the mystery with him.”
Song Ping was surprised, “Hey, you’re making it sound like we’re going on a secret rendezvous!”
“Huh? Did I guess wrong?” Wen Xining tilted her head, sighing, “Poor Zhang Rui, left sour under the lemon tree.”
Song Ping told her not to talk nonsense; she only admired Yi Shi for his intelligence. Who wouldn’t like a smart, handsome guy? As for Zhang Rui, nothing was certain yet. As long as he didn’t confess, she wouldn’t act, seeing who could hold out longer.
Wen Xining continued her work while Song Ping helped clean the lab bench. Suddenly, Wen Xining made an exclamation, “Huh? How could this be?”
Song Ping turned around, seeing Wen Xining hurriedly move to the lab bench, placing the paper under a microscope. After a moment’s observation, she opened a cabinet, taking out several bottles to mix reagents.
“What’s wrong?” Song Ping asked curiously, “Didn’t you already figure it out? What are you mixing now?”
Wen Xining’s skilled technique in mixing powders and solutions made her look like a potion-brewing witch. She quickly shook the test tube, and after preparing the solution, she took a clean dropper from the rack. “This could be a discovery more important than the code.”
Song Ping leaned closer, watching as Wen Xining carefully covered the parts of the paper with pen writing, then cautiously applied a small amount of the solution to the text. After applying it, she placed the paper in a small dark compartment, bending down to observe closely.
Song Ping also stared intently at the compartment. In the dim light, the solution applied to the pen marks gradually emitted a faint… blue fluorescence?!
“Indeed,” Wen Xining’s brows furrowed, “I suspected something off with the spectrum, and I was right.”
“What did you use?” Song Ping picked up the brown bottle from which the powder was taken, “Luminol?!”
The faint blood reaction indicated the ink contained traces of blood. Due to the minimal amount and the oxidation of the blood, it appeared dark brown, making it hard to distinguish from the black ink.
To achieve this effect, the simplest method was to write with blood-soaked ink. Song Ping’s mind conjured up an image of someone bound, with their wrist cut for blood. The USB drive was given by a woman, right? Could she do something so gruesome? It’s possible; some female criminals use horrifying methods, making bloodletting seem mild in comparison.
The more she thought about it, the more horrified she felt. She rubbed her arms, smoothing down the goosebumps that had appeared. According to Yi Shi’s analysis, that woman was not one of Pang Daozi’s accomplices, but for some reason, Song Ping felt that she might be even more terrifying than Pang Daozi’s group.
—
Night had fallen, and the moon hung high in the sky. After the winter solstice, the days grew shorter and the nights longer. It was only six o’clock, but the sky had already turned dark, sprinkled with countless stars.
People in the examination department were clocking out one after another. Those passing by Yi Shi couldn’t help but glance at him curiously. Firstly, his face was unfamiliar, and secondly, he was cold and silent, sitting there without playing with his phone or reading a book. The incandescent light above him was slightly overshadowed by his complexion. If not for the rhythmic blinking of his narrow almond-shaped eyes, one might mistake him for a lifelike wax statue.
The lab door opened slightly, and Song Ping poked her head out, waving at Yi Shi. He walked in, and Wen Xining, wearing a mask, greeted him, “Hello, I’m Wen Xining from Haijing’s trace evidence department.”
“Yi Shi.”
Wen Xining nodded. His voice was pleasant, low, and cold, instantly dropping the room temperature a few degrees, making her want to turn on the central air conditioning.
After a brief introduction, Wen Xining handed him the completed report. “Sorry to keep you waiting. We found something unusual that I think will surprise you.”
Yi Shi took the report and flipped through it. The scanned images showed the symbols – ※∧R. The right stroke of the “∧” was slightly shorter, likely due to imprecise handwriting.
Mathematical symbols and English letters? Yi Shi’s brows furrowed briefly before relaxing. He turned to the next page, which contained a spectrogram and luminol reaction analysis data. His pupils constricted as he immediately looked up, “Whose blood? Human or animal? Can we extract DNA?”
“I can’t say for sure. The trace amount is too small; I’m not confident about successful purification,” Wen Xining clenched her fist, “Let me try. If it doesn’t work, we’ll ask the experts at the provincial lab.”
Yi Shi nodded, turned to leave, then remembered something and turned back, “Thank you.”
There were only a few people in the large office. Those who needed to be on duty were out, and those who could go home had already clocked out. The light in Captain Yuan Kang’s office was still on, and through the open blinds, he could see Yu Xue inside, having a pleasant conversation over tea.
Liu Chenyi was pretending to study case files, frequently looking up to check the door. Finally, seeing Yi Shi return, he hurriedly closed the files, eager to ask if they had found anything on the paper. But Yi Shi had already walked over, and his impatient demeanor made him look like he was awaiting an imperial decree. Feeling embarrassed, Liu Chenyi slowed his pace.
Just two steps away from the desk, Liu Chenyi leisurely picked up his teacup, waiting for Yi Shi to hand over the report. He thought to himself that this kid still knew to show respect to his seniors at Haijing, not as aloof and ignorant of social norms as he appeared.
Yi Shi walked straight past Liu Chenyi to the captain’s office.
“…” Liu Chenyi leapt up, causing his chair to make a loud noise. The young colleagues tidying up looked up to see Lao Liu glaring at Yi Shi’s back, his face dark as a pot’s bottom, as if he wanted to devour him whole.
Yi Shi knocked on the door, then handed the report directly to Yu Xue upon entering. After a few days of working together, Yuan Kang had realized that this guy followed rules strictly. But they were in Haijing, not Nanyi. Shouldn’t he show a bit of courtesy to the host?
Yuan Kang’s gaze fell on the report and then on Yi Shi’s expression. His eyes were calm, as if he didn’t even notice anyone else in the room. Fine, reports from their bureau, and the captain didn’t get the first look.
Yu Xue seemed accustomed to this, not minding Yi Shi’s lack of greeting, and handed the report to Yuan Kang. “This looks detailed. Your trace evidence work is meticulous and thorough.”
“Girls are more attentive,” Yuan Kang smiled but didn’t take the report. “Captain Yu, don’t you want to look first?”
“I was just about to get some water,” Yu Xue picked up his teacup, speaking casually. “Yi Shi was here to deliver the report, and since I was closer, I just passed it along. Here it is; you can take a look.”
With that, Yu Xue went to get water, making it seem natural and as he had described. Yuan Kang’s opinion of Yu Xue deepened. This guy was too shrewd, resolving any potential conflict caused by his subordinates’ actions with a single sentence and gesture. With such sharp mind, it would be a waste if he didn’t get promoted to the provincial department.
Yu Xue, holding his freshly filled tea, patted Yi Shi on the back, “Why are you still standing?”
Yi Shi found a stool and sat down with Yu Xue. Yuan Kang frowned and pushed the report over. Yu Xue glanced at it, “Oh, what’s this? The first is a mathematical symbol, the second is an exponent, a logical operator, or a Greek letter?”
Yuan Kang was puzzled, “This inverted V has so many meanings?”
“Yes, it’s written large, so it’s unlikely an exponent symbol. It could be a logical operator or a minimization operator in fuzzy mathematics. And there’s an ‘R’ after it, which could be the eleventh Greek letter, Lambda, a constant in physics.”
Yuan Kang was once again shocked, feeling like he’d entered a knowledge blind spot. Yu Xue spoke so casually about things he’d never heard of, let alone had any input on. Judging by Yu Xue’s age, he’d graduated from police academy over a decade ago. Did they offer advanced math and physics courses back then?
Yu Xue seemed to notice his confusion and smiled, “Science students like to delve into all sorts of details.” He looked at Yi Shi, “What are your thoughts?”
Yi Shi stared at the paper, slowly shaking his head, “Higher mathematics isn’t my strong suit.”
“Then don’t focus on that. Tell us what comes to mind. Your thinking is the most flexible in our team; don’t let my words restrict you.”
Yi Shi was never confined by others’ words; he just had no immediate thoughts. Yuan Kang turned to the last page of the report. Yu Xue scanned it, adjusted his glasses, “It should be human blood. What did the trace evidence team say?”
“We need to wait.”
Yu Xue understood the difficulty of purifying such a tiny blood sample and feared that even scientific methods might be insufficient. Yuan Kang tapped his pen on the table repeatedly, sighing, “Making it so complicated, do they really want us to save people?”
“There must be some special circumstances that necessitate this,” Yu Xue said, blowing away the steam from his tea. “The woman who delivered the message was very cautious. She couldn’t expose herself or provide complete information. If we could find her, it might greatly help the case.”
It was getting late, so Yuan Kang closed the report and suggested discussing it at the meeting tomorrow. Yu Xue massaged his neck and, along with Yi Shi, returned to the guest house. Coincidentally, Ding Ju and the others had just returned and invited Yu Xue to dinner. Before they could ask Yi Shi if he wanted to join, he had already gone back to his room.
“Dog, has he been ordering takeout recently?” Li Changsheng asked.
Ding Ju shook his head. Sharing a standard room with Yi Shi, he had never seen him order takeout. Apart from drinking water, he never ate anything in the room.
Li Changsheng stroked his chin, “I’ve only heard of fairy maidens drinking dew; I didn’t expect fairy men to do the same. Maybe I should try it sometime.”
Shao Shiqing nudged his shoulder, “Look in the mirror and see if you have the face to drink dew.”
Everyone laughed heartily, but Yu Xue, being considerate, packed a meal for the “dew-drinking” one and asked Ding Ju to take it back.
—
At the meeting the next day, the symbols and letters sparked a lively discussion. Regardless of feasibility, everyone had some ideas, and the whiteboard was filled with their thoughts. Only Yi Shi sat quietly, arms crossed, his expression calm and detached from the noisy atmosphere.
Sitting opposite him, Song Ping had high hopes for the “little brother,” believing he could come up with unique insights and amaze everyone. Zhang Rui, sitting one seat away from Song Ping, enthusiastically discussed his views with a colleague. Noticing Song Ping’s attention wasn’t fully on him, his enthusiasm dampened considerably.
“Listening to you, ‘R’ could indeed be an abbreviation for Restroom, Restaurant, etc. But where exactly? There are restrooms and restaurants everywhere,” the colleague nudged Zhang Rui’s arm. “Go on. I think your theory makes sense and is worth considering.”
Zhang Rui felt a bit annoyed, “Thanks. At least someone appreciates me.”
Yi Shi glanced at the whiteboard. Some ideas aligned with his own, but he sensed something odd, intuitively feeling that this answer wouldn’t be found through conventional thinking.
“I think this ‘※’ isn’t a mathematical symbol but a pattern. Doesn’t it look like a flower? The one next to it might be scissors, and this ‘R’ stands for Rose, so it should be in a botanical garden!”
Liu Chenyi was thrilled, convinced his deduction was correct. The botanical garden happened to be near the tail end of the Southern Cheng’an mountain range, making it convenient for Pang Daozi’s group to handle hostages!
Indeed, many people showed expressions of sudden realization, seemingly agreeing with his theory. Even Yuan Kang and Yu Xue were discussing it quietly. Liu Chenyi felt a surge of pride and glanced at Yi Shi, expecting to see him awkwardly losing his spotlight. To his surprise, Yi Shi didn’t even lift his head, his long, thick eyelashes drooping indifferently.
In fact, Yi Shi had been listening all along, but after hearing it, he dismissed it. According to the nursery rhyme’s hint, the location must be in a tall building. There were no tall buildings in the botanical garden, and the flowers inside would only backfire as a cover.
However, he agreed that the first ‘※’ might be a pattern. His thoughts were in the same direction. The inverted ‘V’… Yi Shi rubbed his temples, feeling a bit confused, and stood up to find a place to smoke.
As soon as he stood up, the noisy conference room fell silent, and all eyes focused on the cold and handsome man. Yi Shi always had this ability to become the center of attention effortlessly, yet he was unaware of it. He had intended to leave quietly, but now, everyone was watching him instead of the whiteboard.
Their eyes were full of anticipation. This person had been silent, and finally, he was making a move! Was he about to show off his skills and make a groundbreaking statement like yesterday?
Yi Shi was puzzled, not understanding what they were expecting. Was it Liu Chenyi’s theory they wanted his opinion on?
“Botanical garden? Impossible,” Yi Shi said lightly and left through the back door.
Liu Chenyi’s face changed several times, suspecting Yi Shi was doing it on purpose, always acting superior. In just two days, their enmity had deepened.
Shao Shiqing happened to be drinking water and choked. He whispered to Yu Xue, “I bet Xiao Yi didn’t think of anything.”
Yu Xue wouldn’t take that bet. It was obvious. Yi Shi didn’t do it on purpose. This had always been his temperament. He just stood up to leave for a while, either to smoke or wash his face. His teammates were used to it.
Besides, if Yi Shi ever had the mindset to provoke deliberately, he would finally seem more human. Those who knew him well understood how indifferent he was. His emotions were like a perfectly balanced scale. He had no special preferences for food, and his feelings for people were the same. Since joining the criminal investigation field, his world seemed to consist of only two kinds of people—ordinary people and criminals.
Yi Shi found a quiet spot in the small two-story building at the back, where it was cool. There was a sign—Forensic Examination and Identification Center. Unlike their bureau, Haijing’s forensic department was in a separate building, while the technical department was in the main building. His first thought was that this design was inefficient, wasting time sending evidence back and forth.
This place was usually deserted. As he walked, he finally heard a phone playing from an office. An elderly forensic doctor was watching a short video, laughing so hard that the wrinkles on his face nearly swallowed his eyes.
“What’s the matter?” The old forensic doctor saw Yi Shi and immediately turned off his phone, switching to a serious expression in an instant.
Yi Shi shook his head and waved the unlit cigarette between his fingers, indicating he was just looking for a place to smoke. He told the old doctor to continue watching, assuring him that it was almost lunchtime and he wouldn’t report him to the Haijing leadership.
The old forensic doctor stood up and looked him over. The young man seemed unfamiliar, likely one of the people from Nanyi here to handle a case. He beckoned Yi Shi to come in and gestured for him to close the door.
Yi Shi looked around for a “No Smoking” sign but didn’t see one. The old forensic doctor said, “What’s the matter? Are the rules in Nanyi so strict that you’re scared?”
Not really. In their bureau, the forensic department was run by an unmarried man in his forties who turned it into a smoky mess due to his heavy smoking habit. It was said that a few times, while working late shifts, he would come out for a smoke in the hallway mid-autopsy. The only light in the dark corridor was the red glow of his cigarette, making it look like a horror movie.
Yi Shi noticed the old forensic doctor’s name tag, Gu Yan, and no longer stood on ceremony. He closed the door and found a place to sit. He felt his pocket, realizing he didn’t have a lighter, and extended his hand to the old doctor.
“Kid, you come to smoke but don’t bring a lighter. Don’t forget to bring your gun when you go to battle!” Gu Yan glared at him, opened a drawer, and casually threw him a lighter.
“Thanks,” Yi Shi said calmly, covering the flame with his slender fingers to light his cigarette.
“Hey, kid, do you know your bureau’s forensic doctor Qi Wenyu?” Gu Yan asked.
“Yes,” Yi Shi nodded. “You’re his mentor. Nice to meet you.”
“Oh, that kid mentioned me?” Gu Yan leaned back, his hands resting on his belly. “That rascal insisted on transferring to Nanyi, and it’s been ten years in a flash. He only visits me during the two major holidays each year. He’s worse than those who go to the countryside to offer condolences.”
“Spring Festival and Mid-Autumn?” Yi Shi asked.
“…What else? Qingming, Winter Solstice?”
Yi Shi didn’t reply, but his eyes clearly said, “You mentioned it yourself.” Gu Yan complained a bit, then suddenly sat up and stared at Yi Shi. “Hey, tell me the truth. How’s Qi Wenyu doing with his partner at your bureau?”
Yi Shi was confused, “…Does he have one?”
“What? That kid told me they’ve been together for years! It’s so public that even the janitors at Nanyi know! So, he never had a partner? Does he ever tell the truth?!” Gu Yan was furious. “He transferred to Nanyi to chase that partner! Someone from the criminal investigation team, a name that sounds like Yu, now doing quite well. See, I knew they wouldn’t fancy him. He fooled me for years!”
Yi Shi was stunned. Combining the information, it seemed a lot like… Yu Xue?
Speaking of Yu Xue, he was also always single, never seen with a girlfriend, not even a rumor. Yi Shi had no interest in gossip and naturally didn’t care about his colleague’s love life. But thinking about it now, it was indeed odd that someone with Yu Xue’s qualities wasn’t dating.
Yi Shi was dazed, feeling like he had inadvertently stumbled upon a secret story. Gu Yan continued to lament, feeling betrayed by his unfilial student.
Yi Shi hurriedly finished his cigarette and left the forensic building. As he approached the main building, he saw Yu Xue coming out. Yu Xue had his jacket draped over his arm, walking steadily down the steps, looking more like a finance executive heading to sign a contract than a criminal investigator.
“Just in time, I need to talk to you,” Yu Xue said, pulling out a car key from his pocket and tossing it to Yi Shi. “Go back to Nanyi and bring something over. If it’s too late, come back tomorrow.”
Yi Shi caught the car key, frowning, feeling like Yu Xue hadn’t finished speaking.
Sure enough, Yu Xue added, “Take Yu’an from the station in front and give him a ride back. He has a competition in the city tomorrow.”
“…I knew it wouldn’t be that simple. He asked Sheng Yu’an to come back, and now you’re asking me to take him personally,” Yi Shi grumbled.
Yu Xue, noticing his reluctance, smiled, “Yu’an came to see you, and you sent him back with a word. The kid felt wronged and couldn’t even complain. This is Sheng’s order. When a big leader speaks, can you not listen?”
Sheng Yu’an’s father, Sheng Guoning, worked at the provincial office and was also Yi Shi’s adoptive father, making Yu’an his non-blood-related younger brother. Few people knew about this relationship. Yu Xue was one of the informed ones. Sheng Yu’an admired Yi Shi, calling him brother and even inviting him home for meals.
Yu Xue dragged Yi Shi toward the parking lot. “Yu’an told me he didn’t mean to interrupt your work. What could he do with the sports team training here? The kid felt wronged, getting scolded for no reason. You really have the heart for that.”
“…He was carrying a hiking bag.”
“Yes, planning to go hiking in Southern Cheng’an Mountain with his friends but didn’t make it. Since you worry he might get into danger, why not take him back? Tomorrow is the weekend, forensics won’t be working, and you can take a break and think about how to solve those symbols and letters.”
Yi Shi had to sit in the car. He started the engine and asked, “What do I need to get from the bureau?”
“Some physical evidence. I’ve already informed the bureau. Oh, right,” Yu Xue adjusted his collar, “also go to the forensics department.”
Yi Shi’s eyelids twitched. He swallowed his curiosity and doubts without showing any emotion, just as he always did, focusing solely on the task at hand.
Thanks for the chap!