Outside the phone booth, Gu Zhixing’s footsteps halted five meters away. Lu Chenzhou hung up the receiver; the metal earpiece base knocked against the body of the phone, producing a brief, crisp sound. He pushed the door open and stepped out; the cold evening wind rushed into his collar. Gu Zhixing stood by the rusted railing, hands in the pockets of his trench coat, gazing at the silhouette of distant factory chimneys against the sky. Hearing the door hinge turn, he turned his head, his gaze behind gold-rimmed glasses calmly sweeping over Lu Chenzhou’s face. “Got it all clear?” Gu Zhixing asked. “A peripheral informant from the Zhao Mingcheng case, provided a few vague pieces of information.” Lu Chenzhou walked towards him, his steps steady. “Just got word that person moved to the old sanatorium area west of the city last month. Might know some people Shen Yan was in contact with before his death.” “The sanatorium west of the city.” Gu Zhixing repeated it, his tone betraying no emotion. “That area’s been abandoned for almost ten years.” “That’s why it’s suitable for hiding people.” Gu Zhixing looked at him for two seconds, then turned and walked towards the black sedan parked by the roadside. “Get in. We can still make it before dark.” As the car door closed, the corner of Lu Chenzhou’s left eye twitched slightly. He turned his face to look at the scenery speeding past outside the window. His fingertips unconsciously traced patterns on his knee, dismantling the structure of a nonexistent pen cap—once, twice, three times. Gu Zhixing started the engine; the dashboard lit up with a dim blue glow. Only the low hum of the engine filled the car. “How is Vice Captain Qin’s progress over there?” Gu Zhixing suddenly spoke, his voice as steady as if discussing the weather. Lu Chenzhou’s fingertips froze mid-air. “She’s in charge of the physical evidence chain verification,” he said, his pace measured. “My focus is mainly on the social connections line.” “That’s true.” Gu Zhixing turned the steering wheel halfway; the car turned into a quiet old street. “Leave professional matters to the professionals. However…” He paused. “I heard Vice Captain Qin is recently investigating an old case, somewhat related to that incident of yours from back then.” The streetlights outside the window began to thin out. Lu Chenzhou felt his breathing grow lighter. Something in his chest tightened slowly, like an invisible hand winding a spring. He turned his head to look at Gu Zhixing’s profile, outlined by the faint light of the dashboard. “Lawyer Gu is very well-informed.” “In our line of work, we have to know what our clients care about.” Gu Zhixing smiled, the expression vague in the dim light. “Shen Yansheng is very concerned about your state, Mr. Lu. After all, you are now working for Shen Yan.” “My state is very stable.” “Good.” The conversation broke off. The car drove out of the city limits; the lights on both sides grew increasingly sparse until only the small patch of darkness cut by the headlights remained. The road began to bump, tires crushing over gravel, making fine cracking sounds. Lu Chenzhou looked out the window; the black outlines of a cluster of buildings appeared on the distant hillside, like a pack of crouching giant beasts. They had arrived at the sanatorium. The iron gate stood half-open, its rusted hinges groaning in the wind. Gu Zhixing stopped the car but did not immediately turn off the engine. He sat in the driver’s seat, his gaze looking past the steering wheel, fixed on the cluster of buildings. A few seconds later, he pulled out the key. “Let’s go,” he said. Both men got out. Lu Chenzhou stepped onto the gravel ground, the soles of his shoes making faint friction sounds. The air carried a mixed scent—damp earth, rotting wood, and a faint, lingering trace of disinfectant. He looked up; the three-story main building stood in the darkness, most of its windows broken, like empty eye sockets. Gu Zhixing had already reached the iron gate, pulling a set of keys from his trench coat’s inner pocket. He found one, inserted it into the padlock—the lock core turned with an unusually smooth sound, unlike something that had been abandoned for ten years. “You’ve been here before,” Lu Chenzhou said. “Scouted the place last week.” Gu Zhixing pushed the gate open; it creaked inward. “Shen Yansheng instructed that any potentially connected locations must have their risks assessed in advance.” He turned slightly, making a gesture of “after you.” “You first, Mr. Lu.” Lu Chenzhou did The doors on both sides of the corridor were tightly shut, with only the ajar door at the end letting out a sliver of light. Lu Chenzhou walked toward it, deliberately slowing his pace with each step, allowing his gaze to sweep over the walls, floor, and ceiling. Large patches of the wall plaster had peeled away, revealing the concrete underneath, but the peeling patterns in certain areas were too regular—as if they had been pried off intentionally. He stopped before that door. The door was an ordinary wooden one, its paint mottled, but the doorknob was polished and bright, without a trace of rust. Lu Chenzhou reached out, his fingertips pausing a centimeter away from the handle. He looked back at Gu Zhixing. Gu Zhixing stood in the middle of the corridor, hands tucked back into his pockets, giving a slight nod. Lu Chenzhou pushed the door open. The sound of the door hinge turning was dull and smooth, as if it had just been oiled. The interior of the room unfolded before his eyes—from the doorway, the view was completely unobstructed. It was a ward, about twenty square meters in size, with an iron-frame bed against the wall, the sheets old but neatly spread. Opposite the bed was a wooden table, one of its legs missing a corner, propped up with a brick. A high window was positioned directly above the table, its glass grimy, but at that moment, a beam of dim yellow light slanted in, cutting through the dust floating in the air. The angle of that beam of light was too precise. Lu Chenzhou paused for a second at the threshold. His gaze swept quickly across the entire room: the position of the iron bed, the tilt of the table, the shape of the light beam falling on the floor, the clutter piled in the corner… Every detail was seared into his mind like a brand. Then he stepped into the room, his demeanor as calm as if he were walking into any crime scene. Gu Zhixing followed him in but did not venture further. He stopped by the door, leaning against the frame, standing sideways—a position from which he could see the entire room and observe Lu Chenzhou’s every move. "This place…" Lu Chenzhou began, his voice unusually clear in the empty room. "Has been kept remarkably intact." "Yes," Gu Zhixing’s voice came from the doorway, carrying a hint of inquiry. "Does Mr. Lu think this kind of ‘intactness’ was formed naturally, or has someone deliberately maintained it?" Lu Chenzhou did not answer immediately. He walked toward the center of the room, the soles of his shoes stepping on the concrete floor, each step stirring up fine dust. His gaze fell on the iron-frame bed—the sheets were coarse cotton, washed to a pale white, but their edges bore neat creases. He crouched down, aligning his line of sight with the mattress. There was a ring of dark stains around the edge of the mattress, irregular in shape, as if left by repeated soaking. "Someone lay here," Lu Chenzhou said, his tone flat. "For quite some time." "A patient?" "Or a prisoner." He stood up and turned to the wooden table. The surface of the table was empty, but near the edge, there was an area where the dust was thinner, forming a rectangle—as if some object had been placed there for a long time. Lu Chenzhou reached out, his fingertips hovering two centimeters above that area, sensing the temperature difference in the air. Then he saw the lunchbox. In the corner between the table and the wall, an old aluminum lunchbox lay half-open, toppled on the ground. The edges of the lunchbox were covered with dents from knocks, and the inner walls retained dark brown, dried stains, like the residue of moldy food scraps. Lu Chenzhou’s breath hitched for a moment. This detail was too specific. He crouched down again, not touching it with his hands, merely examining it carefully. The lunchbox was a common style from the 1990s, with a blurred peony pattern printed on the side. The wear was concentrated on the lower right corner—the spot most frequently rubbed by the thumb when held in the right hand. The distribution of the stains inside also followed a pattern—concentrated at the bottom and on one side of the inner wall, indicating that the user was accustomed to pouring their vegetables over the rice and always tilted the lunchbox toward the same direction when eating. These characteristics, he had seen them in the case files from seven years ago. No, not in the main body of the case files. It was in an inconspicuous witness statement in the appendix, mentioning that the victim had a habit during his lifetime: using an old aluminum lunchbox to carry his lunch, always pouring stir-fried vegetables onto the right side of the rice and starting to eat with a spoon from "So the lunchbox's appearance means either the person who set this up didn't understand how the sanatorium actually operated, or..." Lu Chenzhou paused briefly, "it was intentionally left as a psychological anchor." The room fell silent for a few seconds. Only the faint sound of wind from the high window, and the subtle noise of dust floating slowly within the beam of light. Lu Chenzhou remained in his squatting position, able to sense Gu Zhixing's gaze resting on the back of his neck, like some kind of cold probe. Then Gu Zhixing laughed, his laughter very soft. "Psychological anchor." He repeated the term, as if savoring it. "An interesting way to put it. What does Mr. Lu think the person who arranged this room wanted to anchor?" Lu Chenzhou finally stood up. A slight ache came from his knees. He turned around to face Gu Zhixing. Three meters separated them, the dim light reflecting two blurred halos on Gu Zhixing's glasses. "To anchor the observer's attention," Lu Chenzhou said, his pace steady. "To make the observer notice this abnormal detail, and then generate associations—associating it with the marginal information in the case files that wasn't accepted as evidence, associating it with the victim's habits during their lifetime, associating it with... the possibility that this room might be more than just an abandoned ward." "Then what is it?" "A testing ground." As his words fell, the air in the room seemed to solidify. Gu Zhixing didn't move, still standing there with his hands in his pockets, but Lu Chenzhou saw his Adam's apple roll slightly—a swallowing motion. "Testing whom?" Gu Zhixing asked. Lu Chenzhou met his gaze. "Assuming the person who set this up is Shen Yan's enemy, wanting to test Shen Yanqing's reaction to the details of the old case. Then everything here—" he raised his hand, sweeping it across the room, "this beam of light deliberately adjusted to a specific angle, this bed with suspiciously positioned stains, and this lunchbox, are all meant to trigger Shen Yanqing's specific memories. To see if he would recognize these details, and if he would thereby reveal more information." "A very reasonable speculation," Gu Zhixing nodded. "But there's a problem." "What problem?" "If it really is testing Shen Yanqing, why choose this location?" Gu Zhixing took a step forward, the soles of his shoes rubbing against the floor with a rustling sound. "This place is remote, hidden, but that also means the probability of Shen Yanqing coming here personally is extremely low. A more reasonable approach would be to set up the testing ground near Shen Yan's residence, or places he frequents." Lu Chenzhou felt the twitch starting again at the corner of his left eye. He forced that muscle to relax, but didn't dare shift his gaze away from Gu Zhixing's face. "Perhaps the person who set this up doesn't care whether Shen Yanqing comes personally or not," he said. "Perhaps the test subject is anyone who enters this room and has sufficient understanding of the old case." "Like you?" The moment the question was thrown out, Lu Chenzhou heard his own heartbeat drumming in his eardrums. He stared at Gu Zhixing, trying to catch any trace of emotion behind those gold-rimmed glasses—sarcasm, probing, or something more dangerous. But he saw nothing. Gu Zhixing's expression was as calm as a deep pool of water. "I do indeed have knowledge of the old case," Lu Chenzhou finally spoke, his voice steadier than he expected. "But the person who set this up couldn't have predicted I would come. Unless..." "Unless what?" "Unless the person who guided me here is the very one who set this up." The words fell like a stone into stagnant water. A crack finally appeared in the calm on Gu Zhixing's face—not shock, not anger, but a subtle expression almost akin to appreciation. He raised his right hand and pushed his glasses up, an action he had performed three times tonight. "A brilliant deduction, Mr. Lu," he said, his tone revealing neither praise nor criticism. "But there's a simpler explanation: I was merely following Shen Yansheng's instructions to bring you here to investigate possible leads. As for why this room exists, why it has these details..." he spread his hands, "I'm also very curious." *Lies.* Lu Chenzhou's fingertips curled at the seams of his trousers. Gu Zhixing was lying, and lying extremely naturally—steady tone, self-consistent logic, even with a touch of appropriately placed confusion. But it was precisely this perfection that exposed the flaw. A genuine "assistant," upon hearing such a subversive speculation, should not react with calm analysis as his first response, but rather with vigilance, skepticism, or at least a demand for more evidence. Gu Zhixing hadn't. He seemed "Old K." Lu Chenzhou uttered that name while observing Gu Zhixing's reaction from the corner of his eye. "Only the person who personally designed that interrogation back then would know the specific application methods of these psychological pressure tactics. The lunchbox, the lighting, the stains on the bed... these are all 'pressure points' in an interrogation, used to gradually dismantle the psychological defenses of the person being questioned." Gu Zhixing remained silent for several seconds. "If it really is Old K," he slowly began, "why would he recreate those methods here? To relive the past? Or to... test a new subject?" The last few words were spoken very softly, almost swallowed by the wind outside the window. But Lu Chenzhou heard them clearly. He felt a chill rise from the base of his spine, slowly crawling up the back of his neck. Test a new subject. This room, from the optimal viewing spot upon entry, to every meticulously arranged detail, to Gu Zhixing's leading questions—everything was pushing him toward one conclusion: this wasn't to test Shen Yanqing. This was to test him, Lu Chenzhou. To test his reactions when faced with the psychological environment of the old case, to test whether he could recognize those tactics, to test which line of thought his mind would follow. And Gu Zhixing, this "accompanying" assistant throughout, was the conductor of the test. Lu Chenzhou turned around, his back to Gu Zhixing, facing the high window. The dim, yellowish beam of light stung his eyes. He took a deep breath, letting the smell of mildew and dust fill his lungs, forcing himself to calm down. He couldn't reveal his hand. Revealing it now would be tantamount to telling the other party he had seen through the test. Then the next round of testing would become more covert, more lethal. He had to perform, to play the part of a misled yet still sharp expert, giving Gu Zhixing the expected reaction. "Regardless of who arranged this," Lu Chenzhou spoke, his voice regaining its steadiness, "the investigative value of this room is very limited. It's too deliberate, like stage scenery. A real crime scene wouldn't have such neat, stacked psychological symbols." He heard the sound of fabric rustling behind him—Gu Zhixing had moved. "So your conclusion is?" "My conclusion is, this place might be the practice ground of some psychology enthusiast or crime copycat. But any direct connection to Old K... the evidence is insufficient." Lu Chenzhou turned around to face Gu Zhixing. "My suggestion is to photograph and archive it, then leave. The focus should still be on Shen Yan's social connections from before his death." Gu Zhixing looked at him, his eyes narrowing slightly behind his glasses. That appraising gaze had returned, as if assessing the authenticity of a piece of art. A few seconds later, he nodded. "That makes sense," he said, his tone returning to a professional flatness. "Let's head out then. It's getting dark, this place isn't very safe." He walked toward the door first, his pace neither hurried nor slow. Lu Chenzhou followed behind. Before stepping over the threshold, he took one last look back at the room. The lunchbox still lay in the corner, gleaming with a cold metallic sheen in the dim light. Lu Chenzhou crouched beside the foot of the bed, his gaze falling on the old aluminum lunchbox. Light slanted in from the high window, cutting precisely across the edge of the lunchbox, casting a sharp line of light and shadow on the surface of the dried stains. The stains were a dark brown, with irregular diffusion patterns at the edges—traces left by some semi-liquid food after prolonged, undisturbed drying. On the lower right corner of the lunchbox were three parallel dents from impact. Their depth, spacing, and degree of wear perfectly matched the blurry close-up photo in the case file. That close-up had only appeared once, in the internal evidence photo collection of the special task force from back then. The photo had no number, was sandwiched among a pile of unrelated scene environment shots, and wasn't even listed in the case file index. "The lunchbox..." Lu Chenzhou's voice sounded in the empty ward room, tinged with a perfectly measured confusion, "this shouldn't be here." He didn't turn around, maintaining his observing posture. In his peripheral vision, Gu Zhixing's leather shoes appeared at the edge of his sight—black Oxfords, the uppers spotless, even the angle at which the heels met the floor maintained a certain deliberate stability. "Oh?" Gu Zhixing's voice came from behind, steady and clear, as if reading a legal document, "Mr. Lu believes it should be somewhere else?" Lu Chenzhou's fingertip tapped lightly once on his knee—a habitual movement when he was thinking—but he stopped after just that one tap. He couldn't let Gu Zhixing Gu Zhixing stood two steps away, his hands hanging naturally at his sides. Behind his gold-rimmed glasses, his gaze rested calmly on Lu Chenzhou’s face. That face held no extra expression, only a focused, patient waiting for an answer. But Lu Chenzhou noticed—Gu Zhixing’s right index finger was unconsciously, very lightly, rubbing against the seam of his trousers. An extremely subtle motion, steady in frequency, as if counting. “Your memory truly is remarkable, Mr. Lu,” Gu Zhixing said, a faint, almost imperceptible smile touching the corner of his mouth. “You even remember a lunchbox from the physical evidence list seven years ago.” “Just a vague impression,” Lu Chenzhou shook his head, his eyes sweeping the room again. “But this room… it’s too deliberate. Starting from that ‘best viewing spot’ at the door, to the angle of this bed’s placement, to the position of this lunchbox—everything feels like carefully arranged exhibits, waiting for someone to come in and view them.” He paused, deliberately infusing his tone with a hint of professional judgment: “If this was meant to test Shen Moqing, the arranger certainly put in the effort. Recreating the psychological pressure environment of the old case, down to restoring such details. But the problem lies precisely there—it’s too perfect, losing its sense of reality. A real crime scene wouldn’t be this… tidy.” Gu Zhixing did not respond immediately. He took two steps forward, stopping beside the iron-framed bed, and reached out to touch the edge of the bed. His movement was light; his fingertips lingered on the rusted iron pipe for two seconds before withdrawing. Lu Chenzhou saw a faint dusting of dark red rust powder on his fingertip. “You’re right, Mr. Lu,” Gu Zhixing said, his voice betraying no emotion. “The arranger did indeed pursue perfection. But what do you think is the purpose of this ‘perfection’? Is it to make the test subject believe in the scene’s authenticity, or… to test whether the subject can see through this perfection?” Here came the question. Lu Chenzhou’s heart gave a heavy thump in his chest. He felt the corner of his left eye begin to twitch slightly—that damned physiological reaction under stress. He forced himself to relax his facial muscles, maintaining an expression of calm analysis. “Both,” he said, his gaze meeting Gu Zhixing’s. “If the test subject is Shen Moqing, the arranger hopes that when he sees this room, it will trigger his memories and emotional reactions to the old case. But at the same time, the arranger is observing—observing whether the test subject will be led astray by these ‘perfect details,’ whether he will focus excessively on a particular part and overlook the intention behind the overall layout.” As he spoke, his mind was racing furiously. Gu Zhixing’s question was guiding him to think about the “test subject’s” reaction pattern. Not “how would Shen Moqing think,” but “how would the test subject think.” This subtle shift in phrasing had already appeared three times in their previous conversation. The first time was about the lighting: “If a person were locked in here alone…” The second time was about the space: “What effect do you think the size of this room would have on a person’s psychology?” This was the third time: “Can the test subject see through this perfection?” Each time, Gu Zhixing was pushing Lu Chenzhou’s thoughts in the same direction—making him step into the role of the “test subject,” making him analyze the “test subject’s” psychology, making him evaluate the “test subject’s” reaction. And Gu Zhixing himself remained in the observer’s position all along. Lu Chenzhou’s fingertips began to grow cold. It wasn’t because of the room’s temperature, but because he suddenly understood one thing—this test, from start to finish, was never prepared for Shen Moqing. That “Chenxi Behavioral Correction and Image Management Consulting Co., Ltd.,” that expert team specializing in micro-expressions and body language imitation, that secret subsidiary company that was suddenly deregistered four years ago, its employees’ whereabouts unknown… Gu Zhixing came from there. No, Gu Zhixing might be part of that “control layer.” “Mr. Lu.” Gu Zhixing’s voice cut through his thoughts. “Hypothetically—just hypothetically—if the person who arranged this room, their true purpose wasn’t to test Shen Moqing, but to test another person… what kind of traits do you think that person should possess to be selected as the test subject?” The air in the room seemed to solidify. Dust drifted slowly within the dim yellow beam of light, like a silent countdown. Lu Chenzhou could hear his own breathing, the sound of his "That person..." Lu Chenzhou spoke slowly, each word treading on the edge of a blade, "should have a deep understanding of the old case, ideally a firsthand witness or investigator from back then. They need sufficient professional expertise to recognize the psychological pressure tactics used in this room. At the same time, they must harbor some... preconceived notion about Shen Yanqing, which would make them easily believe the room was prepared for Shen Yanqing." He paused, letting his gaze sweep across the room once more before finally settling on Gu Zhixing's face. "Most importantly," he said, his tone calm as if stating an objective fact, "that person must have their own weakness. A weakness that the arranger can precisely target. For example, an obsession with a certain detail, a sensitivity to a particular emotion, or... an excessive craving for the truth." Gu Zhixing smiled. It wasn't a happy smile, nor a mocking one. It was a... confirming smile. Like a mathematician finally deriving the last step of a formula, like a chess player seeing the opponent's inevitable losing move. He raised his hand and adjusted the gold-rimmed glasses on the bridge of his nose. The look in his eyes behind the lenses became exceptionally clear in that instant—so clear that Lu Chenzhou could see his own reflection in them: an experimental specimen standing at the center of ruins, being carefully observed. "Makes sense," Gu Zhixing said, his voice carrying a relaxed satisfaction. "It seems the arranger, despite their effort, still left traces of artifice. Too eager to showcase their 'expertise,' they ended up revealing their intentions." He walked toward the doorway, stopping at that "best viewing spot," then turned to look inside the room. From this angle, the entire layout of the room was clear at a glance—the bed, the meal box, the high window, the deliberately aged stains on the walls, and Lu Chenzhou standing in the center of the room. "Mr. Lu," Gu Zhixing said, his tone seemingly casual yet laden with meaning. "After this investigation, what do you think... whose reaction was really being tested?" The question had arrived. The final question, and the deadliest one. Lu Chenzhou felt a layer of cold sweat seep from his back. His shirt clung to his skin, bringing a chilly sensation. His brain screamed, warned, urged him to flee—but he couldn't. He had to stand here, had to give an answer, had to complete this performance. He took a deep breath, filling his lungs with air, then slowly exhaled. Then he met Gu Zhixing's gaze, his tone as flat as if discussing the weather: "Naturally, Shen Yanqing's," he said, even tilting his head slightly, showing just the right amount of confusion. "Who else?" Silence. A silence that lasted five seconds. Gu Zhixing stood at the junction of light and shadow in the doorway, his expression blurred in the dimness. Lu Chenzhou could only see the faint glint reflected in his lenses, could only hear his steady breathing, could only feel those eyes analyzing his every subtle reaction inch by inch, like a scanner. Then, Gu Zhixing smiled. This time, it was a real smile—the corners of his mouth lifted, fine wrinkles appeared at the corners of his eyes, his entire posture relaxed. He reached out and pushed open the old wooden door; the hinges groaned dully. The cold air from the corridor outside rushed in, diluting the room's mingled smells of mildew and disinfectant. "Time to head back," Gu Zhixing said, stepping aside to make way. "Shen Yansheng is still waiting for your investigation report." Lu Chenzhou nodded and stepped toward the doorway. His footsteps were steady, each one landing firmly on the solid concrete floor. As he passed Gu Zhixing, he caught a faint scent of cologne—cedar mixed with amber, steady and expensive. It was the perfume Gu Zhixing always used, but at this moment, the scent churned Lu Chenzhou's stomach. He walked out of the room and into the dim corridor. Gu Zhixing followed behind him, footsteps unhurried, always maintaining a distance of three steps. Those footsteps echoed in the empty corridor, like a rhythmic tapping, thud, thud, striking Lu Chenzhou's nerves. They crossed the corridor, descended the stairs, and walked out of the abandoned sanatorium building. Outside, the sky had completely darkened. The early winter night wind carried a biting chill, whipping up dead leaves and dust from the ground. The black sedan was still parked in the same spot, like a beast lurking in the shadows. Gu Zhixing walked to the driver's side and pulled open the door. He didn't get in immediately but glanced back at Lu Chenzhou. "Mr. Lu," he said, his voice particularly clear in the night wind. "Today's investigation was very valuable. Shen Yansheng will Gu Zhixing settled into the driver's seat and closed the car door. The sound of the engine starting was particularly jarring in the silent night. The headlights flicked on, two beams of white light slicing through the darkness, illuminating the pothole-riddled concrete road ahead. Gu Zhixing shifted into gear, released the handbrake, and the car slowly pulled away from the ruins. Silence filled the interior. Only the low hum of the engine, the faint crunch of tires over gravel, and the warm air blowing from the AC vents. Lu Chenzhou watched the night scenery receding rapidly outside the window—withered trees, abandoned factory buildings, scattered lights on the distant edge of the city. Everything looked like faded film, smeared into blurry ribbons of color on the glass. Then, Gu Zhixing turned on the stereo. What flowed out was a piano solo. Lu Chenzhou’s breath hitched. It was Chopin’s *Nocturne* Op.9 No.2, but the performance version was peculiar—the tempo was fifteen percent slower than the common version, the volume of the left-hand accompaniment was pressed extremely low, yet the melody line of the right hand was exceptionally clear, each note seeming to cautiously probe something. This version was Lu Chenzhou’s favorite to listen to before he went to prison. He had only heard this version on a privately collected record, a live recording by a certain deceased pianist, never officially released. In the whole world, no more than three people knew about it. One of them was that "Old K" who had been in charge of interrogating him back then. Lu Chenzhou’s fingertips began to turn cold. He felt the blood receding from the ends of his fingers, leaving behind a numb chill. He forced himself to remain calm, forced his gaze to continue looking out the window, forced his breathing to maintain a steady rhythm. But he knew Gu Zhixing was observing him. From the rearview mirror, from the corner of his eye, from every possible angle inside the car. This music wasn’t being played at random. It was a continuation of the test—testing his reaction upon hearing this piece, testing whether he would exhibit any abnormality, testing if he still remembered the meaning behind this version. The piano notes flowed through the car’s cabin. Slow tempo, sorrowful, carrying a kind of restrained despair. Each note was like a fine needle, piercing deep into Lu Chenzhou’s memories, stirring up the silt that had long settled. He remembered the last time he listened to this music—three days before entering prison. That night, he sat on the sofa in his apartment, playing this record over and over. His younger sister, Lu Chenxing, was asleep in the bedroom. The date for her heart surgery was already set, and the money had been gathered. He knew what he had to do the next day—to sign that fabricated confession, to trade ten years of freedom for his sister’s chance to live. That night, this music kept him company the whole night. And now, this same music was flowing from Gu Zhixing’s car stereo, inside this confined space, on this night just after a psychological test had concluded. Lu Chenzhou closed his eyes. Not because he was tired, but because he needed to hide—to hide any emotion that might leak from his eyes, to hide any possible contraction of his pupils, to hide any physiological reaction Gu Zhixing might capture. He leaned back in his seat, letting his body relax, letting his breathing remain even. The piano music continued to flow. Then, Gu Zhixing spoke. His voice was very soft, almost drowned out by the music, but every word reached Lu Chenzhou’s ears clearly: "Mr. Lu's professional expertise is truly well-deserving of its reputation," he said, looking straight ahead, his hands steady on the steering wheel. "Shen Yansheng will certainly be very satisfied with today's 'investigation report.'" Lu Chenzhou did not open his eyes. He merely gave a soft "Hmm," as if brushing it off, as if tired, as if acknowledging he heard but didn't want to respond. But he understood clearly in his heart—this sentence wasn't praise, wasn't a summary, wasn't a polite remark. It was a confirmation. Gu Zhixing was confirming that Lu Chenzhou had completed the "test," given the "correct" reaction, played the role of the "misled expert" well. At the same time, he was hinting—today's investigation report would be written according to the conclusions Lu Chenzhou had provided: the room was set up to test Shen Moqing, had value but contained obvious flaws, the person who set it up left traces of artifice. And this conclusion was precisely what Gu Zhixing (Old K) wanted. Because only then would Lu Chenzhou continue to believe that he was still investigating in secret, that he hadn't been He knew he had just undergone a psychological test personally designed and proctored by the real killer. He knew that by performing "being misled," he had temporarily lulled the other party. But he also knew—this lull would not last long. Gu Zhixing (Old K) was a top-tier psychological manipulator. He would certainly reassess at some point, would definitely set up more tests, would surely use more sophisticated methods to verify whether Lu Chenzhou's reactions were genuine. And Lu Chenzhou had to be prepared before that. He had to find a way to fight back, had to find evidence, had to drag out this demon hiding behind the mask of a legal advisor. But first, he had to survive. He had to survive in this cat-and-mouse game, survive until the day the truth was revealed. The car stopped at a red light. Gu Zhixing's fingers tapped lightly on the steering wheel, the rhythm perfectly in sync with the piano music from the speakers. He turned his head, glanced at Lu Chenzhou, his eyes inscrutable in the dimness of the car's interior. "Mr. Lu," he said, his tone as casual as if making small talk. "Do you think... if that old case were reinvestigated now, could new evidence still be found?" Lu Chenzhou turned his head, meeting his gaze. Their eyes locked. In that instant, Lu Chenzhou saw something in Gu Zhixing's eyes—not probing, not assessing, not pretense. It was a kind of... interest. The interest of a researcher in an experimental subject, the interest of a chess player in an interesting opponent, the interest of a hunter in a cunning prey. "Perhaps," Lu Chenzhou said, his voice calm. "Perhaps not. But regardless, the truth is always there." Gu Zhixing smiled. The light turned green. He stepped on the accelerator, and the car drove back into the night. The piano music continued to flow, Chopin's "Nocturne" was nearing its end, the final note trembling and dissipating in the air, leaving a long aftertaste. Lu Chenzhou looked out the window. He knew the next round of testing was perhaps already on its way. And this time, he had to win.