This was the first time Shen Xinghe had appeared before them like this. This face overlapped perfectly with the one on his student ID photo, and it also merged seamlessly with the silhouette of the person standing at the Guangyuan cafeteria window a few days ago.
On the day the news broadcast aired, the cafeteria auntie had been sighing at the small television screen in the dining hall while enthusiastically scooping out food for the students. The hand holding the meal tray at the window moved slightly. Following that hand upward was a face wearing glasses. He had glanced at the television beside him and said a quiet “Thank you” as the cafeteria auntie served his food.
“Do you know why we looked for you?”
“Not entirely sure.”
“You weren’t attending classes at Guangyuan, nor did you ask your teacher for leave. What did you go to the auto repair shop for?”
“I’m interested in auto repair.”
“You’re currently a senior in high school, and your grades rank first in the entire grade. You’re interested in auto repair?!”
“…”
In the interrogation room, the youth wore an off-white woolen sweater. He was entirely composed and somber. Through his spectacle lenses, the criminal investigators opposite him couldn’t see the expression in his eyes clearly; it seemed as if a lot of things were hidden there, yet it also seemed like there was nothing at all.
Because he had been participating in car repairs over the past two days, a band-aid was stuck onto the second joint of Shen Xinghe’s index finger. The pad of his other index finger rubbed against the band-aid a few times before he said nonchalantly, “The classes at school are too boring.”
The investigator pressed, “You’re not even taking exams?!”
Shen Xinghe replied, “Early admission shouldn’t be an issue.”
A dead silence fell over the room. Shen Xinghe wasn’t bragging when he said this; he was merely stating a plain fact: “That’s why I said it’s too boring. I wanted to find something to do.”
The investigator raised his voice slightly: “Find something to do? Of all the things you could do, why on earth did you choose to become an auto mechanic?”
Sitting opposite them, Shen Xinghe truly didn’t look like a suspect. He had excellent grades and good looks; at a mere eighteen years old, he belonged in a classroom studying. Although the killer from the previous cat-killing case was even younger than him, it was precisely because that killer was young that he couldn’t control his emotions, making his hatred for his younger brother blindingly obvious. But none of that could be seen in Shen Xinghe.
He said flatly, without much emotion, “I told you, I’m interested.”
“Why didn’t you notify your teacher?”
“Because the teacher wouldn’t have let me out.”
His attitude toward the auto repair matter was incredibly firm. The interrogating officer shifted to a different question: “Your phone was confiscated by a teacher. What page were you browsing on your phone at the time?”
Shen Xinghe answered fluently, “The news. It was a push notification.”
“You pay that much attention to the news?”
“An incident happened at a nearby school. The whole city is paying attention.”
“…”
The large glass window of the observation room was very close to Shen Xinghe’s position. The youth was sitting almost directly in front of them. Chi Qing and Xie Lin could clearly see the expression on Shen Xinghe’s face as he spoke through this glass pane.
Xie Lin noted, “He’s very calm. Even though we caught him, this matter is probably going to be a bit difficult to handle.”
Before long, Ji Mingrui stepped out from the adjacent room: “This kid is way too calm. That mouth of his won’t budge no matter what you say!”
It was precisely his overly composed reaction that made everyone present realize—even though they had apprehended him, they currently didn’t possess enough concrete evidence to charge him. They had originally thought, how difficult could a high school student be to deal with? They hadn’t expected him to actually be quite a tough nut to crack. Shen Xinghe seemed absolutely certain that they lacked conclusive evidence for now.
Xie Lin squeezed Chi Qing’s hand through his glove, playing with it for a long while before suddenly thinking of something.
Chi Qing also thought of something: “Let me go over and try touching him.”
Although he had absolutely no interest in what others were thinking and had no intention of prying into anyone’s mind, he would occasionally remember Yu Lan’s large, gentle eyes. It seemed as though something had changed imperceptibly. At certain times, he no longer felt aversion or fear.
Xie Lin didn’t loosen his grip on his knuckles: “Do you know what the power of science is? Modern science can also read whether he’s lying.” Turning his head toward Ji Mingrui, Xie Lin added, “Hook him up to a polygraph and try.”
Under normal circumstances, unless absolutely necessary, they rarely used a lie detector. Most suspects under interrogation would still expose flaws through their emotions or dialogue. Reaching the step of a polygraph meant they truly had no other leverage against the suspect.
“A polygraph cannot be used as direct evidence, but it can induce a sense of psychological pressure,” Xie Lin explained. “When a person knows their lies will be detected through machine sensors, can they still speak so nonchalantly? His pulse, his heartbeat, his heart rate, his blood pressure, his respiration—which one of these won’t ‘betray’ him?”
The cold machine was quickly laid out on the table. Following instructions, Shen Xinghe placed his right index finger onto the sensor, and his wrist was subsequently fastened with a red strap. Several wires were connected to the polygraph, one of which led to a computer. An electrocardiogram-like display appeared on the monitor screen on the desk, responsible for gathering different frequency band data.
If the data turned abnormal, the waveform would shift accordingly. While the line changed from green to red, the machine would emit a sharp sound.
The conversation resumed. The questions cycled back to the very first one. The investigator sitting before Shen Xinghe re-asked the previous question: “Do you really not know why we looked for you?”
Shen Xinghe only cast a brief glance at the machine when the equipment was being fitted before coldly averting his eyes. Then, he repeated his previous answer: “Not entirely sure.”
“You transferred to Huanan City?”
“A family member’s job relocation.”
“Had you heard of Honghai No. 6 High School before?”
“I didn’t pay much attention to it before the incident.”
“…”
Shen Xinghe’s tone of voice never fluctuated once. The waveforms on the computer screen bounced gently up and down within a flat, narrow range. After a brief pause, he added, “…Could I have a glass of water?”
Shen Xinghe’s features were cold and detached. He didn’t actually possess much approachability; it was merely the glasses on the bridge of his nose that neutralized that impression, concealing his coldness and making him appear more refined. Resting his fingers against the wall of the glass, he took a slow, unhurried sip of water.
Handed over to him right alongside that glass of water was the death case file from Honghai No. 6 High School. Four different times were written on the cover of the file. A black gel pen had written four lines, each representing the time of a person’s death. Just as he set down the water glass, the investigator flipped open the first page according to instructions from the adjacent observation room.
The first page showed Wang Yuan, who had been discovered in the small woods.
“Do you know this person?”
“No,” Shen Xinghe set down the glass, looking at Wang Yuan’s photograph without a single ripple in his eyes. He added, “I don’t know why you’re showing me these.”
The waveform continued to float gently up and down along the baseline. Even with Wang Yuan’s photograph and death record laid out right in front of him, the machine couldn’t capture any fluctuation from him. The polygraph remained completely silent from start to finish.
Everyone couldn’t help but furrow their brows.
“If he really did it,” Ji Mingrui muttered, encountering someone like this for the first time, “then his psychological resilience is truly unmatched. He’s like an iron wall, completely airtight.”
Even an outlier like Xie Lin, who usually observed people as if under a microscope, failed to capture any useful details regarding the case from his reactions. He had to admit a stark fact: “Interrogating him might be useless. We still need to go look for evidence. His motive for murder is very obvious; it’s related to the death of his younger brother, Xu Xingzhou. In other words, there is definitely something fishy about Xu Xingzhou’s death. Aside from the killer, the person who knows this best is Jiang Yiyun—the killer’s final target whom he failed to eliminate.”
The interrogation was proving useless, and even the polygraph was entirely futile. They didn’t have time to continue wearing themselves out with him here.
Xie Lin reminded Chi Qing, “Put on your coat. It’s quite chilly outside tonight. Let’s make a trip to Jiang Yiyun’s house.”
However, just as the group prepared to depart, a shift occurred in the waveforms on the computer display screen.
“Wait—” Ji Mingrui cast a glance over before leaving, spotting the curve. “His heartbeat is accelerating.”
Although it was infinitesimal and nowhere near the threshold required to trigger the alert, it was Resoundingly speeding up.
Chi Qing noticed the file laid out before Shen Xinghe: “The file in front of him has already been flipped forward two pages. As long as they turn one more page…”
“As long as they turn one more page, it will be the profile of the final victim,” Xie Lin finished.
They knew perfectly well who the final victim was. It was “Yu Yang,” whom the killer believed her to be. Out of all these individuals, she was the only person the killer had once intended to spare. If this conversation could force Shen Xinghe to expose a flaw, then Yu Lan on the final page might just be that flaw.
Shen Xinghe’s eyes lowered, watching the investigator opposite him turn the file to the final page. His gaze fell upon the name of the victim on the first line. The paper hadn’t been flipped completely over, leaving half the name obscured.
Yu…
As the preceding sheet of paper slowly fell away, the character behind it immediately materialized: Lan.
Yu Lan’s photograph was pasted on the upper right corner of the file page. The girl had very large eyes, smooth hair, light makeup, and a very faint touch of lipstick. She looked slightly shy as she stared into the lens while taking her ID photo.
Shen Xinghe’s pupils dilated almost imperceptibly. At this exact moment, an expression entirely different from his earlier composure surfaced on his face. His hand resting on the sensor twitched unconsciously.
Among the several different curves, one curve dropped sharply, flattening into a straight line for an entire second.
Ji Mingrui’s upper body practically pressed against the large glass pane in front of him, bringing himself closer to the monitor display. He shouted, “There’s a reaction! His heart stopped for a second!”
The investigator was seasoned and experienced. His peripheral vision captured that one-second pause and drop, and he brought up the deceased person on the page: “She was the victim of that fire case a while ago. You pay so much attention to the news, you must have seen it too. The fire was massive that day. She was waiting for someone in the building to keep a date to watch a movie she had been anticipating for a very long time. But something went wrong that day; an accident occurred, and the door was locked from the outside. She was mute, so she couldn’t even call for help…”
Finally, the investigator stared into the youth’s eyes, asking syllable by syllable: “Do you know her?”
After Shen Xinghe’s heart skipped a beat, it suddenly lost its equilibrium.
The curve on the computer monitor was no longer as steady as before—even though the youth sat there with a countenance and expression no different from when he had first entered. He still looked exactly like an innocent bystander caught up in a misunderstanding; once the interrogation concluded, he would return to school to continue his classes.
After a long pause, Shen Xinghe opened his mouth toward the page covered in written text. His voice carried a slight, faltering stammer:
“I… don’t know her.”
In this conversation, he had uttered the words “don’t know” many times. But this specific response was entirely different from all the instances that came before it.
Because in the very next second after he spoke, the polygraph machine—which had been so silent it seemed broken—emitted its very first sound:
“—Beep.”
