Chapter 26: Gene Sequencing

He Wei and Cheng Zesheng sat together in the living room, just like the last time. Two chairs were facing each other, and from an outsider’s perspective, they appeared to be talking to thin air, amusing themselves.

Cheng Zesheng drew a schematic diagram indicating the shoe prints and the positions of the bodies. He then marked out which ones belonged to the victims and which ones belonged to the third party. After passing the diagram to He Wei, he looked at it and became momentarily puzzled: “What do 1 and 2 mean for the shoe prints near the living room?”

“Based on the distribution of the shoe prints, 1 is the murderer’s, and 2 is the victim’s.”

“But they are the same. The murderer and the victim have similar heights and weights, and they’re even wearing the same shoes. It’s more likely that they’re friends or relatives. What about this side? What does 3 mean?”

“Number 3 is what we found during the previous scene investigation. There was a small stone embedded in the circular tread pattern on the sole of the shoe. Neither number 1 nor number 2 had it, so..”

“So you deduce that there were four people at the scene, but three of them left identical footprints.” He Wei smiled faintly. “Is that how capable this He Wei is? Can even create shadow clones?”

From his tone, Cheng Zesheng could clearly sense a hint of mockery. He furrowed his brows, “Do you think I want to believe that? Leaving biological evidence on the murder weapon that couldn’t possibly have been caused, and the autopsy results are even more bizarre. That He Wei has a ten-year history of allergic asthma, but the bronchi of the body not only had no lesions but also showed evidence of smoking for at least five years.”

“Do the DNA and fingerprints match? Are you sure it’s him?” He Wei rubbed his chin. “Have you investigated my younger brother? He’s my identical twin, so we have the same DNA.”

“We investigated long ago. Even the forensic experts in our bureau couldn’t believe such a bizarre case and suspected they had the wrong person. We’ve already taken samples from your younger brother for genetic sequencing.” Cheng Zesheng shook his head with a sigh. “But I don’t think we got it wrong. The fingerprints match, and there are no two completely identical leaves in the world. In cases involving twins, fingerprints often provide more evidence than DNA.”

Since the beginning of the case, Cheng Zesheng had been suspecting that the deceased He Wei and the He Wei they were investigating were two different people. He had always been skeptical of the idea that one person could have two bodies, but now that parallel worlds were even appearing, what couldn’t be possible? After all, there was a He Wei sitting right there.

“Do you smoke?” he asked.

He Wei smiled, “Why? Are you suspecting that the deceased in your world is me? Then who’s talking to you now?”

“..,” Cheng Zesheng murmured, “I’m not sure either; it’s just a hunch.”

“I don’t have enough information about this case, so I don’t have any leads at the moment.” He Wei suggested, “Bring the forensic and autopsy reports and the physical evidence back tomorrow. I’ll study them carefully.”

“.. Show them to you?” Cheng Zesheng’s voice clearly held hesitation.

“Why not? We’re not working in the same place, and even if I see them, I won’t leak any information. Maybe I can help you solve the case more quickly.” He Wei paused for a moment. “Besides, the one who died is a parallel version of me. I want to see if there’s anything wrong with my own report.”

“No, the issue isn’t there,” Cheng Zesheng reminded him, “If I bring the physical evidence back and you touch it, where else can I find it?”

“If you hadn’t mentioned it, I wouldn’t have remembered. What about the surveillance cameras?” He Wei questioned Cheng Zesheng, “You took them down, and now they are gone. How am I supposed to give them back to the tech team?”

Cheng Zesheng was surprised, “You set them up?!” So he had really misunderstood his father. Luckily, he hadn’t confronted him in a weird tone when he got home. It would have caused a big scene for no reason.

He Wei sneered, continuing to ask about the cameras’ whereabouts. Cheng Zesheng gently told him that he had taken them back to the office last week, intending to take them to the tech team to identify the model. However, they disappeared once he took them out, and the chances of retrieving them were slim.

“Not just slim, but impossible,” He Wei pinched his forehead, sounding helpless. “The atomic structure of the things that don’t belong to this world would collapse if taken out of the node. I can’t even take your fingerprints out, let alone the cameras.”

“..” Cheng Zesheng tried to change the subject, “You’ve had your share of the case; it should be my turn now.”

“Your case isn’t that mysterious. There’s no evidence pointing to an impossible crime at the moment. But the killer and the third suspect present at the scene are both very clever, leaving almost no traces. Oh, by the way, do you also have a brother over there?”

“..He’s dead,” Cheng Zesheng’s voice suddenly dropped, “He died at the hands of drug traffickers; it’s been several years.”

A brief silence fell in the living room. He Wei had intended to dig for information about Cheng Zhenqing, but hearing the somber tone and low spirits in his voice, he changed his mind as the words reached his lips: “My condolences.”

As soon as those words were uttered, the atmosphere in the living room suddenly changed. The deep silence of the night enveloped them. He Wei glanced up, and this time, the time was 12:30, a few minutes later than last time.

The conversation came to an end.

——

After a few days of surveying and visiting around Cheng Zesheng’s residence, Chong Zhen returned with good news: they had finally found information related to Cheng Zhenqing. They confirmed that this person was in Shengzhou City and had indeed been active in the vicinity.

“It wasn’t easy. One team pulled out all the cameras and stored surveillance within a five-kilometer radius for investigation, while another team went around showing his photo, and we got nothing after three days,” Chong Zhen twisted open a bottle of mineral water and took a big gulp, wiping his mouth, “It wasn’t until the night before last that an elderly lady who collects garbage mentioned she had seen Cheng Zhenqing. She had dropped several drink bottles while carrying them, and he helped pick them up for her.”

Wu Xiaolei continued, “This guy really knows how to hide. He rarely goes out, and he’s extremely cautious when he does. He always wears a mask, only revealing his eyes. Where were we supposed to find him? It was that day when he took off his mask to spit out gum, and coincidentally, he saw the old lady drop her bottle. He reached out and helped her, showing his face to her.”

“After that, we re-checked the surveillance according to the elderly lady’s description of his height and build, and we did find a few images of Cheng Zhenqing caught on camera,” Chong Zhen unfolded a folded map and said, “The points marked on it are the locations captured by the surveillance. After connecting the dots, I roughly outlined the activity area. But finding the person is still not easy. Most of that area is residential buildings. Unless we knock on every door, it’s hard to find him.”

Yun Xiaoxiao blinked her big, watery eyes, “You can coordinate with the local police station and check the household registration.”

He Wei looked at the map, the range outlined with a black pen covering four communities, a large supermarket, a comprehensive shopping mall, and even a school and two commercial streets. He asked, “Where was Cheng Zhenqing last seen? And what was he wearing?”

Chong Zhen anticipated that He Wei would ask this, so he had already copied that segment of the surveillance and stored it on his phone. In the video, a tall and lean man stood at a crossroads, wearing a black mask, a black windbreaker, and khaki casual pants. The crossroads on the opposite side had a green light, but he didn’t cross. He waited until the light turned red before turning right onto the pedestrian path and entering an alley.

“There are only two old grocery stores in that alley and no surveillance. There’s also another fork in the road behind, I think he chose that path to avoid surveillance.”

Yun Xiaoxiao leaned in, curious, “If he wanted to take the other path, why did he stand there for so long?”

Wu Xiaolei speculated, “Maybe he hadn’t decided on the route yet?”

“I think he was looking at something. He lifted his head for a few seconds,” Chong Zhen said.

Hu Songkai was lounging on the side, thinking that this kind of matter should be left for Lao He to investigate. Those eyes of his were too sharp; he must have pried the Sun Wukong’s discerning eyes and put them on himself.

Sure enough, He Wei enlarged and zoomed in on the surveillance footage several times, then turned to Yun Xiaoxiao and asked, “Xiaoxiao, did Cheng Zesheng have a branded watch in his endorsement?”

Yun Xiaoxiao nodded quickly and took out her phone, “Yes, yes, there is! That poster looked so cool! I took a picture of it when I saw it on the street.”

He Wei glanced at the screens of both phones, and then concluded, “He was looking at Cheng Zesheng.”

“..?” Wu Xiaolei looked bewildered, and He Wei sighed. With a swipe of his fingers, he enlarged the video, placed it on the table, and got up to make tea.

Chong Zhen and Wu Xiaolei were glued to their phones. Chong Zhen made a meaningful sound first, “Oh, I see now. As expected of Lao He. I have to admit your skills are impressive.”

Wu Xiaolei grabbed Chong Zhen’s arm, “Chong-ge, how did you figure it out?”

“You see, there’s an edge on this video, showing a glimpse of the cuff of a gray suit and the edge of a gold watch, right? Now compare it with the poster Xiaoxiao took. Isn’t it exactly the same?”

Wu Xiaolei widened his eyes, “..That’s a shirt and a watch?” He thought those blurry white, yellow, and gray shapes were an advertisement for cold medicine!

Chong Zhen gave him a regretful look, and Hu Songkai smirked, “Hey, your Captain Heng doesn’t have this skill, right? Why not come to our Criminal Investigation Division? We have plenty for you to learn.”

Wu Xiaolei stared at He Wei’s well-proportioned figure, and his eyes unknowingly carried a hint of admiration. He Wei brewed his tea, completely unaware that he had unintentionally gained a fan from the Anti-Drug Division.

———

Liu Renyu came to find Cheng Zesheng, and Professor Jiang asked him to go to the Forensic Department.

Walking side by side, they discussed Jiang Tan. Liu Renyu shook his head and said, “Vice-Captain Cheng, Professor Jiang’s mood is very bad. I suggest you not ask too much for now. Wait until his mood calms down before talking.”

“..Really? Can it be that bad?”

Liu Renyu’s expression grew serious, and he nodded his chin a couple of times as if emphasizing the severity of the situation. Cheng Zesheng understood, he already had an idea of the outcome. He suddenly thought, if he were to tell Jiang Tan that there was another living He Wei in the house, would it scare him senseless?

“By the way, what was the name of the science fiction movie you mentioned that’s going to be released?” Cheng Zesheng asked.

“Triassic Chronicles.”

“Isn’t that about the dinosaur era?”

Liu Renyu chuckled and shook his head, “The reason it’s called that is because the movie involves three overlapping timelines. The original work has received good reviews. Vice-Captain Cheng, you might consider watching it.”

The two of them had already arrived at the Forensic Department. Jiang Tan sat behind his desk, holding a thermos cup, his eyes fixed on the test reports. The door opened, and Jiang Tan’s eyelids lifted slightly. In a lifeless tone, he said, “You’re here.”

“Yeah, I can tell from your expression that the situation isn’t optimistic. Tell me, I’ve prepared myself mentally.”

Jiang Tan first picked up a report, “This is the result of the DNA methylation difference test between He Lu and He Wei. In the sample DNA building blocks, there are 47 different loci. Analyzed using the Illumina 450K methylation chip, He Wei’s sample contains the?AHRR1?and?F2RL32?genes, which He Lu doesn’t; there are also significant differences in the two CpG loci3?in the COMT promoter region. The detailed content is all in this report, and it can essentially completely distinguish between these MZ twins (monozygotic twins).”

Continuing, Jiang Tan picked up another report, “This one is the DNA methylation difference test for He Wei and the blood sample brought back from the hospital. It used the same DNA building blocks, and unexpectedly, these two DNA samples also have differences in 15 loci. Although both carry allergenic genes, one allergy pathway is related to IgE and the other to IgG.” He picked up the third report, “The sequencing results of the hospital’s blood sample and He Lu’s sample show differences in 56 loci. Do you know what this represents?”

“..Go on.”

Jiang Tan took a deep breath, “This represents that the three samples come from three different individuals. He Lu’s sample has significant differences in DNA methylation from the body and the hospital’s blood sample, ruling out the possibility of being from the same individual; the DNA profiling of the body and the hospital’s blood sample is nearly identical. In general, with a test of 23 loci, we can conclude that they come from the same person, but there is still a methylation difference. Excluding the?chimerism4?that might occur in hybrids and considering the contradictory conditions shown within the body, I can only conclude that these are also two different individuals.”

Although Cheng Zesheng was mentally prepared, holding the actual results still felt quite heavy in his hands. It seemed that anything related to He Wei was distorting the normal rules of science to some extent.

Jiang Tan seemed to release a breath he had been holding, collapsing into a chair, his baby face drooping, “Crazy, it’s crazy.. The same person actually has two different genetic traits. If I hadn’t seen it with my own eyes, I wouldn’t believe that something like this could happen in my entire life.”