After learning that Lu Yibo’s girlfriend was Zhou Qi, Zhang Yi’ang immediately dispatched people to find Zhou Qi to understand the situation, only to discover her phone was already turned off. Checking with the mobile phone service provider, they learned Zhou Qi’s phone had been turned off that afternoon. Subsequently, they went to the hotel to investigate Zhou Qi’s interpersonal relationships with staff members. Through some informants, Wang Ruijun learned that no one had seen Zhou Qi these past few days. Others sent her WeChat messages and she occasionally replied, but when calling her phone, although it was on, no one answered. Officers also went to Zhou Qi’s home and knocked on the door, but no one inside responded.

Time was already late that day, so the investigation could only continue the next day. Who knew that early the next morning, the situation would take a new turn.

Zhou Qi had an older sister who worked as a manager at a KTV in San Jiang Kou. She also hadn’t been able to contact Zhou Qi for several days. Last night when the police asked her about Zhou Qi, she went to Zhou Qi’s home to check after getting off work from the night shift at three in the morning. She had a key to the house. As soon as she opened the door, a strong stench of decay rushed out. Upon entering and turning on the lights, she was shocked to see her sister’s corpse lying in the living room. Frightened, she stumbled out of the house and immediately called the police.

Zhou Qi’s residence was in an old residential complex that looked somewhat run-down. Reportedly, this was a place she had bought with money saved when she used to work as a prostitute. Later, she had purchased a new house in another upscale complex, but it was still being renovated and not yet ready to move into. She used to be a prostitute, and after getting together with Lu Yibo, to avoid causing him trouble, they maintained a secret lover relationship without making it public, so outsiders basically didn’t know.

Zhang Yi’ang got out of the car in the residential complex, leaning on two crutches, and walked toward a residential building across the way, led by Wang Ruijun and Song Xing. He laboriously climbed to the third floor. Police tape had already been put up in the corridor, and police officers who had arrived earlier had already begun investigation work. Just as he was about to enter the house, he noticed a small surveillance camera stuck at the doorway, identical to the one on the ceiling of Lu Yibo’s office. Below the surveillance camera, the police had already placed a marker, waiting for technicians to remove it for inspection. However, it should be the same as before—unable to trace who had monitored this location.

Opening the door, he had just walked a few steps into the house when he felt his stomach churning with nausea and quickly backed out.

It was now November and very cold outdoors, but the central air conditioning inside the house was turned up to the highest temperature. With all doors and windows sealed shut, the entire house was like a steamer. The corpse had been stored inside for many days, emanating rolling waves of foul odor.

Seeing Director Zhang in this state, Song Xing immediately went inside to turn off the air conditioning. According to regulations, the windows had to remain in their original state from the time of the incident to wait for forensic technicians to examine them and couldn’t be opened, so he simply opened the door completely to let the smell inside disperse as quickly as possible.

After ten minutes, the air finally became breathable. Zhang Yi’ang and the others stepped inside. The officers inside were all wearing masks, equally nauseated as they did their work. He roughly surveyed the area in a circle. This house was over seventy square meters with warm décor. To the left of the entrance was a small living room with a sofa and coffee table. Zhou Qi’s corpse lay on the sofa with large amounts of blood beside her.

He walked to the sofa’s edge, took a general look, then walked out of the house and called Song Xing over: “How did she die?”

“Looks like she was stabbed to death.”

“What about the time?”

“Probably just these past few days.”

“Who doesn’t know it was these past few days? I’m asking for the exact cause of death, time, and sequence of events!”

Song Xing frowned: “We’ll have to wait until Medical Examiner Chen arrives to determine that. We’re not professionals. The other forensic investigators are only responsible for crime scene examination.”

“Where is Medical Examiner Chen?”

“He’s on vacation at a farmhouse resort. We already called him earlier—he’s rushing back now, but it’ll probably take another three or four hours.”

Zhang Yi’ang was immediately displeased: “Right after Lu Yibo’s case, he went on vacation to a farmhouse today?”

“Uh… he said that after Lu Yibo’s murder case, based on past murder occurrence probability, it’s unlikely anything would happen these next few days, so he went on vacation.”

Zhang Yi’ang sighed—there was no helping it. San Jiang Kou had only this one medical examiner. Reportedly, he used to have an apprentice who changed jobs last year, and the two new apprentices who came this year were all students who could only do injury assessments. All autopsies depended on Medical Examiner Chen. He monopolized San Jiang Kou’s autopsy business, which is why he had such a tough temper at the unit—no one could do anything about him.

By evening, the investigation work of various departments was completed. Medical Examiner Chen verbally provided preliminary autopsy results—he still needed to conduct further chemical analysis to determine whether the deceased had been poisoned.

Zhou Qi died before Lu Yibo—perhaps on the same day, perhaps the day before. Because some time had passed since the incident, he couldn’t provide an exact time of death. Zhou Qi had been stabbed to death with a dagger—five stabs in a row to the abdomen. The door lock at home was undamaged. Analyzing the scene, the killer was an acquaintance. After Zhou Qi welcomed him into the house, he killed her. There were traces of a struggle at the scene, but the degree of struggle was slight. It appeared the killer struck when she was off guard, and she had little opportunity to resist before being killed. After killing her, the killer stayed at the scene for a long time, including wiping clean fingerprints and footprints everywhere. The physical evidence analysis yielded little harvest. Zhou Qi’s house keys and her phone were not found at the scene. The police believed her keychain had the third key to Lu Yibo’s office, and the killer used this third key to enter Lu Yibo’s office. After the killer took her phone, he didn’t turn it off. For the next several days the phone remained on, until yesterday when it was finally turned off.

Zhang Yi’ang and several other criminal police went through the case again from the beginning.

The killer was someone acquainted with Zhou Qi. He came to Zhou Qi’s home and killed her, taking the keys and phone. Subsequently, the killer took advantage of Lu Yibo’s night jogging to kill him. After that, he infiltrated Lu Yibo’s office to take certain things and installed surveillance to monitor the police investigation’s progress. Everyone believed the time the killer entered Lu Yibo’s office was at night, because during the day the hotel’s office floor frequently had staff moving about—the killer wouldn’t take such a risk.

Zhang Yi’ang instructed his subordinates to do two things: first, retrieve surveillance footage from the residential complex where Lang Botu lived to see if he went out on those evenings; second, check the lobby surveillance at Maple Grove Late Hotel, because to enter Lu Yibo’s office, the killer had to first enter the hotel.

The police worked through the night, and results came out the next morning.

Li Qian told him two things. On the evening of November 5th, after Lang Botu drove his BMW SUV back to the complex, half an hour later he changed clothes and walked out of the complex on foot, not returning on foot until after midnight—an interval of over two hours. His whereabouts during this time were quite suspicious.

Zhang Yi’ang immediately said: “During this time, he went to Maple Grove Late Hotel and infiltrated Lu Yibo’s office.”

Li Qian shook her head again: “But the hotel lobby surveillance has been checked many times—Lang Botu wasn’t found.”

“Could he have disguised himself?”

“The forensic police considered this possibility, but there weren’t many people entering and leaving the hotel at midnight. They checked every person who appeared in the surveillance footage and ruled out the possibility of Lang Botu.”

This posed a difficulty. Zhang Yi’ang lay on the sofa, repeatedly thinking about how Lang Botu could enter and exit the hotel smoothly without being captured by the hotel lobby surveillance.

“Director, could it be… could it really not be Lang Botu who did it?”

“Impossible. He went out for those two hours in the middle of the night—he must have gone to Maple Grove Late Hotel. How could he enter the hotel while avoiding surveillance—” Zhang Yi’ang suddenly widened his eyes and shouted, “Wang Ruijun, quickly call Wang Ruijun.”

After Li Qian called Wang Ruijun over, Zhang Yi’ang immediately asked: “Is there a way to enter Maple Grove Late Hotel without going through the hotel lobby?”

“The hotel back door? But when we went to check the surveillance yesterday, we found the back door was locked. The lobby manager said the back hall is under renovation, so the door has been locked during this time.”

“Besides the back door?”

Wang Ruijun spread his hands: “There’s nothing else. To enter and exit the hotel, you definitely have to go through the lobby.”

“Think about it more carefully.”

“I can’t think of anything.”

Zhang Yi’ang provided the answer himself: “The spa—this kind of establishment definitely has a secret back door leading outside! And definitely won’t have surveillance installed!”

“This… we’d have to go see it ourselves to confirm.”

“Don’t waste precious investigation time!”

“Yes,” Wang Ruijun could only blurt out, “there is indeed a back door, and there’s no surveillance installed there.”

“Are you certain?”

“I… I’m certain. I know about this back door entirely because an informant told me. When we handled cases before, we needed to…”

Zhang Yi’ang had no time to listen to his explanation. He grabbed his crutches and headed outside while instructing them to immediately bring Lang Botu in for interrogation—he would personally conduct it.

“On the evening of November 5th, after you killed Lu Yibo and drove home, why did you change clothes half an hour later and walk out of the complex? What did you go do?” In the interrogation room, Zhang Yi’ang sat between two interrogation team members asking questions. Li Qian and others watched the entire process collectively in the monitoring room.

“Director Zhang, I need to make a correction—I didn’t kill Lu Yibo. His murder has absolutely no connection whatsoever to me.” After being held for a day, Lang Botu’s face showed some fatigue, but his thinking was still very nimble.

Zhang Yi’ang smiled. He didn’t expect this kind of trap to be stepped into by the cunning Lang Botu, so he said: “Then you, being completely innocent, explain what you went out to do after getting home, and why you specially changed clothes—were the original clothes stained with Lu Yibo’s blood?”

“I changed clothes because I took a shower. I went out because I heard something happened with Zhou Rong. He’s had ongoing cooperation with our company, so I was worried it would affect the company’s situation. I was troubled, so after going out I went to the riverside north of the complex to take a walk and calm my mind.” He delivered this answer without any hesitation.

“A walk—a walk that lasted two hours?”

“I lay down on a lounge chair for a while and accidentally fell asleep, then went home later.”

“Didn’t you have a cold? Yet you still ran to the riverside in the middle of the night?”

“That’s why I had a fever the next day—probably because I fell asleep by the river and was blown by an evil wind.”

“Now you’ve connected the entire sequence explaining the cold from beginning to end. You prepared this script for a long time, didn’t you?”

Lang Botu sighed lightly and shook his head: “Director Zhang, I really have not the slightest connection to any murder case.”

“According to our investigation, that evening you didn’t go to the riverside but to Maple Grove Late Hotel.”

“I… how could I go there without driving?”

“Take a taxi.”

“I…” Lang Botu said helplessly, “Leader, what I said is absolutely true. You say I went to Maple Grove Late Hotel—what basis do you have?”

“What kind of basis do you want?”

“Hotel staff testimony, or surveillance on the road or at the hotel capturing me.”

Zhang Yi’ang sighed and laughed: “As expected, you’ve thought everything through thoroughly. You knew that taxi surveillance wouldn’t capture you, the spa has ceased operations, and entering the hotel through its back door means you won’t encounter anyone or be captured by the hotel’s surveillance.”

Lang Botu sighed, feeling very speechless: “I’m truly wronged to death. When investigating Lu Yibo’s death, you should look for Zhou Qi, who had the closest relationship with him. Why are you looking for me?”

“You know Zhou Qi is already dead, so yesterday you deliberately prompted us to look for Zhou Qi, and today you say this again.”

“What! Zhou Qi is dead!”

“Keep performing—the performance is very convincing. San Jiang Kou finally produces a Best Actor, and we’re all watching you. Behind this interrogation room there’s a whole bunch of criminal police watching your performance.”

Lang Botu’s expression changed slightly. After a second, it returned to normal, and he asked back: “How did Zhou Qi die too?”

“This should be asked of you. You first killed Zhou Qi, then killed Lu Yibo—how is it that you’re asking me instead?”

“You’re saying Zhou Qi died before Lu Yibo?” Lang Botu’s eyes widened.

Zhang Yi’ang looked at him strangely: “Yes, is there a problem?”

“That’s… that’s impossible.” Lang Botu swallowed forcefully.

Zhang Yi’ang noticed his expression and immediately pressed: “Why is it impossible for Zhou Qi to have died before Lu Yibo?”

Lang Botu’s eyes flickered, and he stammered: “I… the morning I went on the business trip I saw Zhou Qi. She… if she died, it must have been after November 6th.”

“What!” Zhang Yi’ang and all the criminal police behind the monitors widened their eyes. The autopsy results clearly stated Zhou Qi died one to two days before Lu Yibo—how could it be possible that on the morning after Lu Yibo’s death, on November 6th, Lang Botu still saw Zhou Qi?

Zhang Yi’ang hesitated for a moment, staring at him: “You need to take responsibility for these words.”

“I… that’s just how it is.”

“Didn’t you go to the hospital for an injection that morning? How did you encounter Zhou Qi?”

“I… I saw her on the road while driving.”

“Which road?”

“This… I can’t remember clearly.”

“Are you certain you saw Zhou Qi?”

“Of course. The road was congested at the time, and I even rolled down the window and greeted her.”

“Did she respond to you?”

“She…” Lang Botu recalled, “She responded to me. It was her.”

Zhang Yi’ang closed his mouth. This was unexpected information. Previously, everyone said that during these days after Lu Yibo’s death, no one had seen Zhou Qi. Her phone was on but she didn’t answer calls. When people sent her WeChat messages, she would occasionally reply with a few text messages. Now Lang Botu was saying he saw Zhou Qi on the morning of November 6th. But the autopsy results clearly stated Zhou Qi died before Lu Yibo.

Zhang Yi’ang took a deep breath and rebuked: “You still dare to lie! Our autopsy results show that Zhou Qi definitely died before November 5th. How could you possibly have seen her on November 6th? Why are you the only person who saw her, and yet you can’t specify the exact location!”

“I… so many days have passed—I really can’t remember, but I’m certain I saw her that morning. Have you… have you considered that your autopsy results are wrong, that the autopsy was unprofessional?”

Zhang Yi’ang frowned and pondered. Either Lang Botu was lying, or the autopsy results were wrong. Lang Botu had no need to lie about seeing Zhou Qi on the morning of November 6th, did he? What benefit could this bring him?

Could the autopsy really be problematic? Looking at Medical Examiner Chen’s appearance with his herniated lumbar disc, if he wrote the report incorrectly, that would actually be quite possible.

He said toward the surveillance camera: “You all call Medical Examiner Chen over.”

The criminal police behind the monitors looked at each other. Everyone had watched the interrogation just now and felt Lang Botu had no need to lie about this issue, which meant the autopsy report was wrong. But going to find Medical Examiner Chen to tell him the autopsy results were incorrect—this… who would go? After discussing for a long time, everyone encouraged Li Qian to go. After all, Li Qian was a female colleague—Teacher Chen would still show some gentlemanly courtesy, right?

Li Qian had no choice but to steel herself and go to the medical examiner’s office. When Medical Examiner Chen heard that suspect Lang Botu wanted to see him again, he immediately shook his head like a rattle drum—I’m not going! For colds and fevers you look for me—this isn’t a hospital!

Li Qian explained that this time it wasn’t about seeing a cold—it was another matter.

Medical Examiner Chen snorted coldly and firmly stated that no matter what she said today, even if she talked herself hoarse, he wouldn’t go. He still had scheduled injury assessments for assault and battery cases—he had no time to deal with this nonsense.

Li Qian stammered that this matter was rather urgent and asked Teacher Chen to please go to the interrogation room.

Seeing her expression, Medical Examiner Chen asked strangely: “What exactly is it?”

“That… that…” Li Qian took a deep breath and, trembling with fear, closed her eyes. “The suspect said the autopsy report is wrong. He said our unit’s medical examiner is unprofessional.”

She bit her teeth tightly and waited three seconds before opening her eyes, only to see Medical Examiner Chen grab a scalpel and charge directly outside.

“Knock knock knock”—urgent knocking sounded on the interrogation room door. The interrogator looked up at Medical Examiner Chen through the window and immediately opened the door to welcome him. As soon as he turned the lock, Medical Examiner Chen burst through with a bang, charged straight to Lang Botu, raised the scalpel and held it against his neck: “Was it you who said the medical examiner is unprofessional?”

Lang Botu was locked in the interrogation chair and couldn’t move. He had expected to encounter some methods during the interrogation process, but he never dreamed that during interrogation someone would take a knife to kill him. He was immediately frightened speechless, unable to even shout, only screaming in his heart—help, help, the police are trying to kill someone!

Fortunately, the next second the two interrogators reacted and quickly rushed over to restrain him. Wang Ruijun, Song Xing, and others in the monitoring room saw this situation and quickly ran over. Everyone shouted “Teacher Chen, Teacher Chen, let’s talk this through nicely. We’re all civilized people—there’s no need to use knives.”

After much persuasion, they finally carefully removed the scalpel from Medical Examiner Chen’s hand and convinced him to sit aside.

Zhang Yi’ang explained to him: “Teacher Chen, your autopsy report says Zhou Qi died on November 4th or 5th—in any case, before Lu Yibo. However, Lang Botu says he saw Zhou Qi on the road on the morning of November 6th, so we wanted to consult—”

“He’s lying—he’s the killer!” Medical Examiner Chen pointed at him fiercely. “My autopsy results are absolutely correct. Lu Yibo definitely died on the evening of November 5th, and Zhou Qi definitely died even earlier than him. It can’t be wrong.”

Seeing the danger had passed, Lang Botu could finally speak. He muttered quietly: “I clearly saw Zhou Qi on the morning of November 6th. Your autopsy must have made a mistake.”

“You murderer still dare to lie!” Medical Examiner Chen pounded the table heavily and pointed at him angrily. “I heard you went to Beijing on a business trip on the afternoon of November 6th, right? You want to say Zhou Qi died after November 6th so you’d have an alibi. Am I right!”

“Oh…” Everyone’s eyes lit up one after another, and they couldn’t help but want to applaud in their hearts. They had just been puzzled about why Lang Botu would say he saw Zhou Qi on the morning of November 6th—so it was to create an alibi! No wonder he went to Beijing for inexplicable investment pitch meetings and stayed for several days—there was another purpose.

Under the admiring gazes, Medical Examiner Chen straightened his back, raised his head, and pointed at him proudly: “However, science is science. Your lies have been ruthlessly crushed by science. Your statement and the autopsy results contradict each other, proving you’re lying!”

Lang Botu swallowed and looked up at him, saying timidly: “Why… why can’t it be that your autopsy results are wrong?”

“Because my autopsy reports never make mistakes!”

Facing Medical Examiner Chen’s attitude, Lang Botu gritted his teeth. Seeing the other had no knife in hand and wasn’t afraid of violence with so many criminal police present—fine, he’d go all out. He raised his head and questioned Medical Examiner Chen: “When conducting autopsies to determine time of death, don’t you need to consider factors like weather and temperature?”

“Of course I consider them. Corpses discovered in summer versus winter, indoors versus outdoors—after the same amount of time, the corpse conditions are completely different. If you don’t consider weather and temperature, seeing the same corpse condition would lead to completely different conclusions. Time of death could differ by several days. This tests a medical examiner’s practical experience!”

“Then let me ask you—if a corpse is indoors where the temperature is very high, how would you determine time of death?”

“The actual time of death would be shorter than it appears on the surface.”

“Then that’s it.” Lang Botu pursed his lips.

“What do you mean ‘that’s it’?” Medical Examiner Chen looked at him bewildered. “What are you trying to say? Lu Yibo’s corpse was discovered outdoors—that determination is extremely accurate. Zhou Qi’s corpse was at her home, where the temperature was only a few degrees higher than outdoors. Of course, I factored in these minor differences too. So the results can’t be wrong!”

“About this—” The criminal police suddenly realized something. Wang Ruijun hesitantly interjected: “Teacher Chen, Zhou Qi’s death scene wasn’t originally like that.”

“What do you mean?” Medical Examiner Chen was completely confused.

The criminal police recalled that when they first arrived at Zhou Qi’s home, upon entering it was very hot—they discovered the entire house’s central air conditioning was turned up to maximum temperature.

Medical Examiner Chen immediately flew into a rage: “Why wasn’t the original state maintained? Who turned off the air conditioning!”

Everyone recalled for a moment, then finally directed their gazes toward Song Xing, who was hiding in a corner with his head lowered. Song Xing explained: “I didn’t open the windows—the scene was still maintained in its original state. It was just too stuffy and hot, so… so I temporarily turned off the air conditioning. You arrived late that day, so… so later the indoor temperature returned to normal. I didn’t know it would… would affect the results so significantly.”

Everyone criticized Song Xing—don’t you have even this basic common sense? Are you still a veteran investigator? Can’t tolerate a stuffy crime scene, can’t endure even this little hardship—what kind of police officer are you? Wouldn’t it be better for you to work as a security guard staying in air-conditioned rooms all day?

Scolding aside, everyone suddenly turned their gazes in unison toward Lang Botu: “How did you know about the conditions at Zhou Qi’s home?”

“I… I didn’t say that. I was just giving an example. I didn’t say Zhou Qi’s home.” Lang Botu made feeble explanations.

This time, everyone deeply believed without doubt that he was the killer. All explanations were so futile. But no matter how they questioned him after that, he insisted he had just given a casual example earlier and hadn’t mentioned Zhou Qi’s home situation. He had no connection whatsoever to these murder cases—if you have evidence then arrest me, otherwise release me. Of course they couldn’t release him, but now the most critical issue was how to produce substantive evidence to prove it really was Lang Botu who killed them. Otherwise, they truly had no way to handle him.