Controlled Experiment Chapter 5

Controlled Experiment – 5

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Back in the car, Du Yusheng told Xiao Bai about what had happened.

Xiao Bai's opinion was more or less the same as Du Yusheng's.

"We've got the surveillance footage, what's the point of him lying?" He added, "Does he think we're stupid?"

The corners of Du Yusheng's mouth dipped slightly. "Exactly, what's the point? Pretending to be serious."

"So? Brother Yu?" Xiao Bai gestured out the window. "Any thoughts?"

"What do you think?"

It was a rhetorical question. Du Yusheng smacked his lips and glanced inside.

Huan Island Central Hospital was the largest and best hospital in the city. Whether in terms of medical equipment, staffing, or infrastructure, it was among the top tier. Even the glass on the outpatient building was spotless. Du Yusheng didn't have many outstanding traits, but his eyesight was considered one of the best in the team. From this parking spot, he could see the second-floor corridor quite clearly. He spotted that man immediately, Li Yao had just come out of a consulting room. He hadn't finished his shift and was still wearing that white coat, though he'd undone the buttons to reveal a light-coloured T-shirt underneath. He looked like he'd stepped out of a medical drama.

A young nurse had come over to speak to him. After exchanging a few words, Du Yusheng saw Li Yao bend down to sign something in her notebook, and hen give a polite half-bow. No need to guess, he was certainly wearing that courteous, well-mannered smile again. Although it was their first meeting, Du Yusheng thought that he'd already figured out this young doctor.

Of course, that was just his own impression. Later generations would look back on this confidence of Du Yusheng's and describe it as: idiotic.

"Brother Yu?"

Xiao Bai had to call him twice before Du Yusheng came back to his senses.

"Brother Yu... what are you mulling over?"

Du Yusheng shot him a blank look. "Okay, take him back to the station for questioning."

Xiao Bai was dumbfounded. "... Just take him back like this?"

"What else?" Du Yusheng laughed coldly. "Should we bring him back with gongs and drums, with lanterns and banners?"

Xiao Bai very nearly asked, Aren't you going to call it in first? But on second thought, this was Du Yusheng.

They sat in the car for three seconds. With no movement from Du Yusheng, Xiao Bai blinked in confusion.

"What the fuck are you waiting for?" Du Yusheng snapped. "I told you to bring him in."

"... I'm not the leader... what use is it if I go?" Xiao Bai muttered under his breath.

Du Yusheng had his own plans in his heart. Li Yao was very handsome, he had to maintain a good impression in front of him.

Xiao Bai had expected Li Yao to push back. He was ready for that. But instead, when Li Yao glanced at Du Yusheng's car through the window, their eyes met. Xiao Bai clearly heard the light laugh that escaped Li Yao, and just like that, he was easily taken back to the bureau.

As soon as they returned to the bureau, they bumped into Qin Yan in the corridor. He had just finished dealing with something and, seeing the two of them coming in, met them head-on. Xiao Bai looked deeply troubled, while Du Yusheng appeared pleased with himself. Qin Yan called out to Du Yusheng.

"The case cracked?" Qin Yan smiled. "Look at you, all smug."

Xiao Bai shook his head. "No, we've brought in a suspect, just about to go in and question him."

Du Yusheng raised one finger with a grin. "He. Lied." Then turned to Xiao Bai and said, "Xiao Bai, take the surveillance footage over."

Du Yusheng was notoriously lazy. If someone under him could conduct the interrogation, he would never bother himself. But when it came to this Li Yao, Du Yusheng wanted to ask the questions himself. Partly because the man was easy on the eyes, and partly because, well, why would someone intelligent tell such an amateurish lie? Du Yusheng couldn't make sense of it.

Once everything was ready, Du Yusheng pushed open the door to the interrogation room, holding a laptop, and walked in alone with an air of seriousness.

Li Yao had had his eyes closed, but opened them slowly at the sound, and greeted Du Yusheng with a polite smile.

He was wearing a light-coloured T-shirt, with a dark coat over it that suited his complexion well. He looked like a scholar from a period drama, carrying a whiff of scholarly grace, though without the stiffness or pedantry often seen in academics. Du Yusheng wasn't the brightest, and all that came to his mind was: good-looking.

"Dr Li doesn't seem nervous at all," Du Yusheng smiled as he plonked himself down on the interrogation table.

Li Yao shook his head with a smile. "I'm not sure what I should be nervous about." He looked around. "Is it because I'm at a police station?"

Du Yusheng rubbed his fingers together and casually stood up, leaning back against the one-way mirror and watching Li Yao's expression from a distance.

"I heard Dr Li went abroad with your parents at a young age. Then your parents immigrated, but you came back to China on your own before starting high school, you didn't go with them," Du Yusheng paused briefly, then continued, "Your parents must have really trusted you. You were so young, why didn't you emigrate with them? You're a family of three, after all."

Li Yao looked directly at Du Yusheng's eyes, showing no discomfort at all, as if Du Yusheng wasn't talking about his own family.

"My parents had their own considerations, I didn't have a say in it."

Du Yusheng nodded thoughtfully. "So after you returned to the country when you started high school, you haven't been in touch with them, right? Free-range?"

"......" Li Yao chuckled softly. "Does this have anything to do with the case?"

Walking back to the table, Du Yusheng shrugging indifferently.

"Just making conversation, you know, to get to know Dr Li a bit."

Enough small talk, it was time to get to the point.

"At the hospital just now, what did Dr Li say you were doing on Thursday?" Du Yusheng scratched his head. "You see, my memory's terrible."

"I went home after finishing a surgery," Li Yao repeated. "I didn't see Mr Luo that evening."

"Yo, isn't that odd?"

Du Yusheng turned on the laptop on the table, pressed the play button, and then turned the screen to face Li Yao. The footage on the screen was from the night of Luo Daheng's death, surveillance footage from around the villa. The monitoring equipment in high-end neighbourhoods was decent, and the footage was exceptionally clear. Li Yao quickly appeared in the video. Watching his expression from inside the interrogation room, Du Yusheng let out a barely audible sigh but saw no flicker of emotion on his face.

"Look how clear that shot is," Du Yusheng turned off the laptop and tapped the screen, watching Li Yao with interest.

Li Yao lowered his head and smiled. "Seeing your footage just reminded me I might have remembered it wrong."

That wiped the smile off Du Yusheng's face.

"I didn't go home after surgery on Thursday, it must have been Wednesday." Li Yao raised his head. "I did see Mr Luo on Thursday, and I did go to his house."

"... You're only just remembering this now?" Du Yusheng's fingers drummed heavily on the table. "Bit of a coincidence, isn't it."

"It's been hectic in the department lately, getting dates wrong... is quite normal, isn't it?"

Du Yusheng glanced at the one-way mirror.

"Alright then, tell me, why did you go looking for Luo Daheng?"

"A routine check-up," Li Yao said. "I'm his private doctor, I went to assess his current condition." As though already anticipating what was coming next, Li Yao continued, "There was nothing unusual about Mr Luo that day. I asked him a few questions and then left. Before going, I even reminded him not to stay up late and to get more rest. I was there for... no more than fifteen minutes."

"Fifteen minutes?" said Du Yusheng. "You remember that clearly? Were you timing it?"

Li Yao smiled faintly. "As doctors, we have a strong sense of time. It's an occupational habit."

"That's it? You didn't do anything else? Think carefully." Sitting in front of Li Yao, Du Yusheng crossed one leg over the other.

Li Yao's words sounded rehearsed, like scripted lines, nothing of real substance.

"That's all," Li Yao appeared to be thinking it over seriously. "I went home after that. You've got surveillance, you can check if I went home Wednesday night, and if I went there on Thursday night."

"... We don't need you to tell us that! We'll check it ourselves." Shooting another glance at the one-way mirror, fuming, Du Yusheng pushed the door open and stormed out.

Qin Yan and Xiao Bai had been watching the conversation from outside the whole time, listening in on every word. As Du Yusheng came out, the three of them exchanged a look, clearly neither of the other two had figured much out either.

"What do you two think?"

Xiao Bai looked through the glass at Li Yao, who had closed his eyes again and sniffed lightly.

"That bastard's obviously lying, saw the footage and changed his story."

"... Bastard, is it?" Du Yusheng smacked Xiao Bai on the back of the head. "Who the hell are you calling bastard?"

He didn't even watch who he was swearing at. Du Yusheng turned his head to look at Li Yao. Even though he knew the other man couldn't see him, Du Yusheng still instinctively glanced over, Why did he suddenly seem so wimpy?

"He's lying. And very calm about it," Qin Yan looked at Du Yusheng. "Standard procedure, take his DNA and fingerprints, and I'll take them to the lab as backup."

Du Yusheng nodded. That was what he had in mind as well.

He'd originally thought he could get something out of this interrogation, but in the end, it had all been for nothing.

Achieving nothing, Du Yusheng's mood was poor. He was planning to hold the man a bit longer before letting him go, but just before the end of the shift, a call came in. In short, a patient under Li Yao's care at the Huan Island Central Hospital had taken a turn, and they were requesting him back for a consultation. Li Yao had been solely responsible for this critically ill patient, and no one else dared to step in, so they'd ended up calling the bureau.

After hanging up, Xiao Bai and Du Yusheng exchanged glances.

After a moment, Du Yusheng sighed, jerked his chin at Xiao Bai and said, "Go, let him out."

Xiao Bai felt like he was jinxed, any errand running or getting scolded always fell to him.

When Xiao Bai got back, he thought he could finally clock out but was stopped again by Du Yusheng.

"Send someone to follow him, see where he goes."

After giving the instructions, Du Yusheng sat in his office and turned on his computer.

He'd recently set a new wallpaper, the award ceremony group photo. Du Yusheng opened a photo on the desktop, the photo of the twins that had come in through the anonymous email. Du Yusheng had saved it to the computer. The photo looked more like a prank, but it made him uncomfortable. His mind kept drifting back to it. In quiet moments, he'd find himself staring at it, lost in thought.

Controlled experiment.

What exactly did that mean?

Du Yusheng had a feeling that even if they caught the killer, this riddle might still remain unsolved.

He didn't know how much time had passed when Xiao Bai called.

"Brother Yu, Li Yao didn't go to the hospital," Xiao Bai said. "He went home first."

That wasn't unusual, it was quite likely Li Yao had gone home to fetch something.

Sure enough, five minutes later, Xiao Bai rang again. "Brother Yu, he's left again, should I keep following?"

"Don't," said Du Yusheng. "Go home and rest, I'll take care of the rest."

After hanging up, Xiao Bai still had no idea what exactly the rest referred to.

Grabbing his coat off the back of his chair, Du Yusheng threw it over his shoulders, picked up his car keys from the desk, and headed out the door.

This Li Yao was far too suspicious, Du Yusheng wanted to take a risk.

Li Yao's home wasn't far from the police station. It was in the same district, and without traffic, it would take just half an hour to drive there. It was deep into the night, so the roads were clear. Du Yusheng drove an old banger, called so because it really was ancient. The windows and doors had been replaced after purchase, and on close inspection, the colour differences were obvious. The seats were covered in rough leather, most of them frayed at the edges, and one of the replaced doors still had a manual window crank. Old Master Du had said not to be too flashy when going out, and Du Yusheng had taken that advice to heart, ending up with a car that even a repair shop wouldn't know where to begin with.

Li Yao's neighbourhood wasn't exactly an upper-class area, but it was one of the newer developments. Parked inside the estate, Du Yusheng's ten-times-used car of his looked especially out of place. The owner got out, walked over, and looked from a distance at the window of Li Yao's apartment. That part of the building was pitch black.

Hopefully, he'd find something tonight.

Li Yao lived on the tenth floor. Du Yusheng waited by the elevator for a bit. It was a new estate, with only two apartments per floor, quiet, and spacious corridors.

At the door, Du Yusheng pulled out a set of tools from his pocket and began fiddling with the lock.

Back in school, Du Yusheng wasn't good at much else, but when it came to this sort of thing, he was second to none. One of the professors had said there wasn't a lock Du Yusheng couldn't pick, nor a door he couldn't open.

In a matter of seconds, the rather expensive security door was opened by Du Yusheng without the slightest damage. Du Yusheng tucked the tools back into his pocket, rather pleased with himself. The apartment was unlit, completely dark, and there was a faint fragrance in the air. Reaching behind him, Du Yusheng shut the door and felt along the wall for the switch.

The warm yellow light was not blinding, and the ceiling lamp was stylishly designed; clearly, the owner had put effort into the place.

Du Yusheng's eyes shifted slowly from the lighting fixture downwards and then braked.

He wanted to drag Xiao Bai out of his house and give him a tongue-lashing from head to toe.

Because there stood Li Yao in the living room, wearing a dark blue set of home clothes, holding a clear glass.

The very man who, according to Xiao Bai, had left home, the very man who had supposedly been called to the hospital for an emergency consult, was now standing right in front of him.

Provoking trouble, unlawful entry. Those four words suddenly popped into Du Yusheng's head.

Never mind being a team leader, he suddenly felt like he might not even be able to keep his vice-captain post.

"... Hi, I opened the wrong door," Du Yusheng experienced what it meant to be at a complete loss for the first time. He awkwardly withdrew his hand, took a few steps back and pointed behind him. "Oh, Dr Li, you live here? What a coincidence, I live just opposite."

A lie that could be seen through in an instant.

But Li Yao didn't seem inclined to expose the poor deception. Nor did he appear startled or flustered by the sudden intrusion, almost as if he'd known he'd have an uninvited guest tonight. Du Yusheng watched as he calmly filled his glass with plain water and placed it down on the costly glass coffee table. His house slippers were dark green and looked thick and cosy. They must be really warm to wear, Du Yusheng thought.

"Neighbour?" Li Yao smiled politely. "I've only just moved in myself, I didn't expect us to be living so close."

Du Yusheng chuckled awkwardly a few times. "Exactly, very close indeed, just open the door and there you are... I forgot my keys, you see. And, well, in our line of work, you've got to know a bit of everything, lockpicking's part of the training. It was dark when I came up, I didn't notice and ended up at the wrong door."

Li Yao smiled with his lips pressed together. "You really scared me. Next time you forget your keys, feel free to come in and sit down."

Du Yusheng didn't know what to say, so he simply nodded, thinking to himself: Please, just don't go reporting me to the bureau for breaking and entering. He was already carrying enough pressure from the current case. That junkie incident had forced him to take more than half a month off, and even the Du family name was barely shielding him these days.

Du Yusheng took a few steps back when something suddenly occurred to him.

"... Didn't Dr Li say you were headed to the hospital?"

"No need for me to go now." Li Yao replied calmly as he set the half-empty glass aside and sat down on the sofa, looking at him. "I spoke to them over the phone in the car, they managed to resuscitate the patient, so I'm not needed any more." He added, "I've just come off several night shifts in a row, I'm exhausted, I just want a proper night's sleep."

With that, there was no reason for Du Yusheng to linger.

Before leaving, Du Yusheng apologised and glanced around the entrance. On the console table in the foyer, there was a set of keys. The design was refined, more like a key tag than a standard key.

Du Yusheng had a similar one himself, the key to Old Master Du's villa looked just like that. In other words, this was the same style used for Luo Daheng's villa keys, which meant that Li Yao very likely had access to Luo Daheng's house. A new theory formed in Du Yusheng's mind: even if Luo Daheng wasn't home, with that key, Li Yao could come and go freely.

Leaving Li Yao's apartment, Du Yusheng rode the elevator back down, his ears burning red as he got into the car.

He fumbled for his cell phone and made a call. Xiao Bai had only just gone to sleep when he was immediately woken up.

"What the fuck is wrong with your bloody eyes?" Du Yusheng snapped. "You're thirty, not eighty, can't even fucking tell people apart. Li Yao was fucking at home, you know that?"

Three fucks in one sentence, that was how furious Du Yusheng was. After several minutes of swearing, Xiao Bai finally grasped the situation. He scratched his head, still puzzled.

"But I clearly saw him coming out of the house."

"You saw shit," Du Yusheng shot back irritably. "Oh, and get the apartment opposite Li Yao's, buy it."

"......" Xiao Bai laughed dryly. "Brother Yu, you rich people really do burn money like it's paper, don't you?"

"And you've got the cheek to talk? If it weren't for those useless two holes of yours, would I even need to? One more word and I'll put it on your tab, got it?"

"Alright, alright, I'm on it now." Xiao Bai figured that, at the current prices in that neighbourhood, he couldn't afford a place there even if he lived to ninety-nine.

After hanging up, Du Yusheng lowered the window and leaned out to glance up at Li Yao's floor. There was something strange about Li Yao, every word out of his mouth was a flawless lie, and yet Du Yusheng still couldn't say for sure whether he had anything to do with Luo Daheng's death. As Li Yao himself had said, he was just a private physician, dependent on Luo Daheng's salary. He had no motive to kill. But then why did all the key evidence point straight to him? Du Yusheng lit a cigarette and clamped it between his lips, starting the car slowly.

He felt he needed a good night's sleep too.

‿︵‿︵ʚ˚̣̣̣͙ɞ・❉・ ʚ˚̣̣̣͙ɞ‿︵‿︵

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Translator Notes

Please feel free to comment any mistakes I made so I can improve and do better as I go through the book.

Translated: May 13, 2025 by Angel

Edited: June 1, 2025 by Angel