The icy reality that ended the previous chapter was like a tightly drawn string pressed against Lu Chenzhou's throat. The faint warmth of the steamed buns in his memory had long since dissipated. The chill of the iron plate beneath him, the metallic scent of rust and dust in the air, and the heavy, relentless footsteps of the two search parties resuming their carpet-sweep advance after their brief standoff in front of the loom—these were the only truths of the present moment. His heart hammered heavily against his ribs. His left hand instinctively clenched the photograph he had taken from the small metal box, his fingertips feeling the sharp edge of the photo paper and the raised texture of the blurred handwriting on the back. *August 17, 2005. Linjiang Pier. Shen Yanqing. A strange middle-aged man.* And that back view, suspected to be "Old K," that made his blood run almost cold. He released his grip, stuffing the photograph back into the metal box along with the rusted "047" key. The small box clicked shut with a soft sound. Almost simultaneously, a beam of flashlight swept past the edge of the loom's chassis where he was hiding, illuminating a patch of dark, oily stain on the ground ahead. "Checked this side?" a hoarse male voice asked. "No human scent," another voice, deeper and more subdued, replied with a trained brevity. "But the trail is fresh. Split into two groups, you take left, I'll take right, flank them. Watch the pipes underfoot." Lu Chenzhou held his breath. His lungs seemed to have forgotten how to work, constricted, each tiny expansion bringing a stabbing pain. His eyes darted around rapidly: besides the path he came from on Fang Mu's side, to the left was a narrow passage piled with discarded spindles, to the right a row of rusted electrical distribution boxes, and behind him... behind him was a wall. The flashlight beam wavered again, probing towards the left passage. There was only one fleeting chance—the moment the light shifted away, the moment the searchers' attention was drawn to the left passage. Lu Chenzhou's body released like a compressed spring. He rolled out from under the loom's chassis, staying low to the ground, and without rising, used the strength of his core to dart directly into the shadows behind the row of electrical boxes on the right. The movement was lightning-fast, the rush of air he created almost masked by the footsteps of another search team in the distance. But his sleeve still brushed against a dangling wire, causing a suspended metal connector to strike the box with a faint *ding*. Lu Chenzhou didn't stop. He crouched and slipped through a gap less than half a meter wide between the distribution boxes. His palm, bracing against the ground, became coated in a sticky, unidentifiable black grease. Ahead, a half-open iron door appeared, leading to a downward concrete staircase. The darkness beyond was thick, exuding a sharper stench of mildew and urine. He slipped inside, pulling the iron door closed behind him with a soft hand, not latching it shut, leaving a gap about two fingers wide. Leaning against the cold, damp wall, his heart pounded like a drum in his eardrums. Faint dripping sounds echoed from below the stairs, *drip, drip, drip*, so regular it was unnerving. A few slivers of flashlight light leaked through the door crack, casting shifting spots of light on the floor. "Was this door open just now?" the hoarse voice was right outside. "Maybe it's always been open," the deeper voice replied, but with a barely perceptible pause. "What's down there?" "Old ventilation shafts, lead to the outskirts of the factory zone. Been blocked off for ages." The iron door creaked open fully. A blinding beam of light shot in, sweeping over the cobweb-covered pipes above Lu Chenzhou's head, then slowly moving downward. He was curled in the right-angled shadow formed by the wall behind the door and the start of the staircase, his body pressed tightly against the wall, his breathing suppressed to a thread-like whisper. The edge of the light beam grazed the tip of his shoe—that old leather shoe covered in dust, stopping less than ten centimeters from the edge of the shadow. Every second felt like being ground by a blunt knife. He could hear the sound of his own blood rushing, could feel the pulse on the inside of his left wrist, beating fast and erratic. Fear cascaded like an avalanche, but he forcefully suppressed any sound that might rise in his throat, even breaking down the act of swallowing saliva into the slowest, most minute muscle adjustments. "No one," the deep voice said. The flashlight beam began to withdraw. "Check the left passage. He can't have gone far." Lu Chenzhou didn't move immediately. In the darkness Although the area under the stairs might be blocked off, it was at least a temporary place to escape the search perimeter. He pulled out his phone—the screen had been set to the lowest brightness while hiding—and quickly glanced at the time. 4:17 AM. Eleven hours had passed since he received that encrypted message from Zhou Zhengping about "Old K possibly having a surviving child." Zhou Zhengping's message had been delivered via a voicemail left at an abandoned public phone booth, encrypted with a date code known only to the two of them, pointing to an address in the old northern district: "No. 74 Hongqi Street, third floor, east unit." At the end of the message, Zhou Zhengping's voice was weary and rushed, with the faint sound of porcelain clinking in the background—his habit of turning an old enamel cup when nervous. "Jingyuan," Zhou Zhengping had used his courtesy name in the recording, a rare, almost entrusting form of address. "The thread is hot... I might have been noticed on my end too. If you go, you must be quick. And you must go 'compliantly'." "Compliantly." Lu Chenzhou understood the meaning of that word. He now had Gu Zhixing by his side, the "assistant" sent by Shen Yanqing, shadowing him twenty-four hours a day. Any private action had to be cloaked in the legitimate guise of investigating Zhao Mingcheng's case for Shen Yan. Thus, he needed a performance. A cat-and-mouse game played right under the watcher's eyes, attempting to break free yet being firmly locked in place. This in itself was a test—testing the limits of Gu Zhixing's surveillance, testing the bottom line of Shen Yan's tolerance for his private investigation into old cases, and testing whether that lead itself had long been marked by more dangerous forces. The stairs were steep, the edges of the concrete steps severely damaged, with rusted rebar exposed in some places. The air grew increasingly stale, the smell of mildew mixed with the sour odor of some chemical reagent, growing stronger the further down he went. Sure enough, there was no path below. The bottom of the stairs ended at an arched doorway sealed shut with bricks and cement, the marks indicating it was a project from many years ago. But on the left wall of the doorway, there was a slightly lighter-colored, square area, roughly half a meter on each side. Lu Chenzhou approached and ran his fingers over that area. The wall surface was rough, but the edges were neat, as if some equipment had once been installed there and later removed. He crouched down, retrieved a slender, specially-made steel strip from a hidden compartment in his shoe heel—one of the small tools he had polished himself before going to prison—and slowly inserted it along the seam at the edge of the square area. There was slight resistance, then the steel strip slid in, touching some kind of metal component. He twisted his wrist with extreme lightness, then pushed it sideways. A faint click sounded from within the wall. The square area recessed inward by about two centimeters, then slid open sideways, revealing a dark, narrow pipe opening only large enough for one person to crawl through. A stronger current of air, smelling of rust and dust, surged out from the pipe, blowing against his face. This was part of the factory's emergency maintenance passage from back in the day, not on any blueprints, known only to the old workers. When giving him the address, Zhou Zhengping had also subtly mentioned this "possible old passage exit," located outside the western perimeter wall of the factory area, near a row of bungalows slated for demolition. Lu Chenzhou didn't hesitate. He retrieved the steel strip, lowered himself, and crawled into the pipe. The inner walls of the pipe were cold sheet metal, rusted through in some places, feeling rough and grainy to the touch. He could only rely on alternating pushes from his elbows and knees to crawl forward in absolute darkness. The sense of time vanished, leaving only the rustling sound of his body against the metal, his own heavy breathing, and a distant, rhythmic, low thrumming from deep within the pipe—like the heartbeat of some giant beast. Perhaps it was the residual resonance from the foundations of some large piece of equipment that hadn't completely shut down. After crawling about twenty meters, a faint light appeared ahead. Not natural light, but a pale, fluorescent glow from an energy-saving tube, leaking in through a gridded vent at the end of the pipe. He moved up to the vent and peered down through the rusted iron grating. Below was a small backyard piled with discarded plastic barrels and miscellaneous junk. The yard was tiny, with a low wall, beyond which lay a potholed alley. Across the alley stretched a continuous row of low, single-story bungalows awaiting demolition, most windows dark, with only a few scattered The lattice had completely detached from its frame, flipping outward. He quickly slipped through the gap, his body landing lightly on a pile of soft, discarded foam plastic below that emitted a strange, cloyingly sweet smell, cushioning the impact. He immediately rolled behind a dilapidated concrete laundry sink to one side, crouching low, his gaze sharp as he scanned the entire courtyard and the mouth of the alley. He stood up, brushing off the foam fragments and rust clinging to his clothes. His movements were quick, yet every detail carried a certain deliberate, professional tidiness—this was him signaling to any potential observer: I've escaped danger, but I'm still in control. The alley was narrow, the ground wet from last night's rain, with murky water collecting in the low spots. The air was thick with the complex odors characteristic of the old city: damp earth, rotting vegetable leaves, the sulfurous smell of unburned coal briquettes, and a faint, elusive greasy aroma of fried food drifting from somewhere. He needed a car, or at least a working phone. But before that, he had to dispose of the most conspicuous evidence on him—that small metal box. At the end of the alley stood a green, paint-peeling dumpster, stuffed with all sorts of plastic bags. Lu Chenzhou walked over. Instead of tossing the box directly inside, he tore a relatively intact black plastic bag from the edge of the dumpster, placed the box inside, and casually grabbed a few wads of waste paper and empty drink bottles to stuff around it for concealment. Then, he tied the plastic bag with a complex, hard-to-undo knot before throwing it deep into the dumpster. This wasn't discarding; it was marking. If he needed to, he could come back for it. After doing this, he turned and walked toward the lit end of the alley. His pace was neither hurried nor slow, his back straight, as if he were just an ordinary resident up early for the day. But the corners of his eyes continuously scanned the windows on either side, the shadows on the rooftops, and the activity at the alley mouth ahead. After walking about fifty meters, the alley mouth ahead connected to a slightly wider street. By the roadside, a small convenience store was lit up, with an old man dozing off behind the glass counter. Next to the counter, a red public telephone hung on the wall. "Make a call," Lu Chenzhou said, his voice steady, carrying just the right amount of weariness. The old man said nothing, just pointed at the rate sheet pasted next to the phone. Lu Chenzhou pulled a few small bills from his trouser pocket—the only cash he had, left in his old jacket before imprisonment and carefully hidden away—counted out the required amount, and placed it on the counter. Then he picked up the receiver and dialed a number. The dial tone sounded in the receiver. Once, twice, three times. Just before the fourth ring, the call was answered. "Hello." Gu Zhixing's voice came through the receiver, clear, steady, betraying no hint of being just woken up, nor any surprise. It was as if he had been waiting for this call all along. "Assistant Gu," Lu Chenzhou said, his pace measured, his wording precise. "I'm currently in the north of the city, near Hongqi Street. Ran into a bit of a situation. Need you to come over." He didn't explain what the "situation" was, nor did he say why he was in the old city district, over ten kilometers from the temporary residence Shen Yan had arranged for him, at four in the morning. Silence on the other end for two seconds. In those two seconds, Lu Chenzhou could hear extremely faint background static, and... some rhythmic, faint sound like keyboard tapping? Very light, almost masked by the noise. "Specific location," Gu Zhixing asked, no extra words. "The intersection of Hongqi Street and Jianshe Road, outside the small store on the east side," Lu Chenzhou reported his location, paused for a moment, then added, "Related to clues in Zhao Mingcheng's case. Might need to revisit the old address of a potential witness." "Understood," Gu Zhixing said. "I'll be there within twenty minutes. Stay put, keep your line open." Lu Chenzhou put down the receiver and turned to lean against the outer wall of the store. He fished out a half-crushed pack of cigarettes from his pocket—also an old item, the tobacco long dried out—took one out, and lit it. The brief flare of the match illuminated his face, his jawline tight, his eyes unfathomable behind the smoke. He needed these twenty minutes. Not to wait for Gu Zhixing, but to observe. The old storekeeper had dozed off again. The street was empty, only occasionally a three Lu Chenzhou did not look up, nor did he change his posture. He continued to smoke, even tilting his head back slightly to exhale a puff of smoke towards the gray-blue sky, as if merely relaxing his tired nerves. But the index finger of his left hand, holding the cigarette, curled almost imperceptibly, tapping twice lightly against the seam of his trousers. This was his habitual gesture when thinking. The rhythm of the taps corresponded to 'R' and 'U' in Morse code—'Received, unknown.' The peering from behind the window lasted about ten seconds, then the gap in the curtains closed, and everything returned to its former state. A coincidence? An early-rising resident nearby? Or... another pair of eyes? The "twenty minutes" Gu Zhixing had mentioned was frighteningly precise. In the nineteenth minute, a black, low-key sedan slid silently to the curb and stopped in front of the small shop. The window rolled down, revealing Gu Zhixing's face, framed by gold-rimmed glasses. He wore a crisply ironed shirt, the collar impeccably neat, showing no trace of the haste of being awakened in the dead of night. "Mr. Lu." Gu Zhixing nodded in greeting, his tone polite yet distant. "Please get in." Lu Chenzhou stubbed out his cigarette, opened the car door, and sat in the passenger seat. The interior was clean, carrying a faint scent of leather cleaner and air conditioning filter. The dashboard's fluorescent glow illuminated Gu Zhixing's profile. His fingers holding the steering wheel were long and slender, knuckles distinct, without any superfluous movements. The car started smoothly, driving into the still-dim street. "The address is No. 74 Hongqi Street, third floor, east unit." Lu Chenzhou gave the address provided by Zhou Zhengping, his gaze fixed ahead. "While reviewing the Zhao Mingcheng case files yesterday, I found an early interview transcript mentioning this person. They might have witnessed Zhao Mingcheng's activities in the area the week before his death. I wanted to go ask some questions." "So early?" Gu Zhixing asked, his tone not questioning, but a calm confirmation. "If the person is still there, going early avoids a wasted trip," Lu Chenzhou replied. "If they've moved, we can still ask the neighbors about their whereabouts." Gu Zhixing said nothing more, only gently adjusted his gold-rimmed glasses. His gaze behind the lenses remained intently focused on the road. The car wound through the narrow streets of the old city district. The sky gradually paled to the color of a fish's belly, but light remained stingy. The buildings lining the street resembled clusters of silent, vaguely outlined giants. Trash cans, clotheslines, illegally constructed awnings flashed by outside the window. Lu Chenzhou looked out the window, seemingly absent-minded. But his mind was racing at high speed, memorizing every intersection, every possible line-of-sight obstruction, every stretch where pedestrian flow might suddenly increase. About five minutes later, the car turned into an even narrower alley. On both sides were old walls six or seven meters high, plaster peeling away to reveal dark red bricks beneath. The alley was barely wide enough for one car. The ground was a pitted stone-paved road, the car bumping along as it advanced. Just then, Lu Chenzhou suddenly spoke: "Turn right ahead, there's a small open space where you can park. Cars can't go any further in." Gu Zhixing complied and turned right. Ahead was indeed a small, triangular open space, piled with some construction debris, empty of people. He parked the car steadily and turned off the engine. "It's about three hundred meters to walk in," Lu Chenzhou said, pushing open the car door and getting out. The early morning air was chilly and damp, carrying the earthy smell of soil into his lungs. He stretched his somewhat stiff shoulders, his eyes quickly scanning the surroundings: to the left of the open space was an even narrower side path, above its entrance, electrical wires illegally strung by a few households hung low like spiderwebs; to the right was a high wall, behind which seemed to be a deserted small courtyard, the branches of a crooked-neck tree peeking over the top of the wall. Gu Zhixing also got out, locked the car door, and walked to a position half a step away from his side. This distance was subtle—close enough to react at any moment, yet not so close as to seem overly familiar. "This way." Lu Chenzhou stepped off towards the depths of the alley. His pace was neither hurried nor slow, the soles of his boots making light *pat, pat* sounds on the damp, slippery stone slabs. The alley was winding, the light dim. After walking about a hundred meters, a T-intersection appeared ahead. Under the eaves to the left of the intersection, a breakfast stall had just set up its stove fire. Steamers At the breakfast stall, Lu Chenzhou took some loose change from his pocket and said something to the vendor. The vendor nodded, lifted the steamer lid, and a cloud of white steam billowed out, instantly enveloping Lu Chenzhou’s figure. The steam was thick, lasting three or four seconds. He didn’t wait for the buns. Instead, using the steam as cover, he took two quick steps backward and to the side, pivoted on his heel, and slipped into the narrow, shoulder-width gap beside the breakfast stall, a dark crevice piled with clutter! The other end of the gap connected to another parallel alleyway! His movements were extremely fast, almost noiseless. Once inside the gap, he didn’t immediately bolt. Instead, he pressed against the wall, holding his breath and listening intently. Back at the breakfast stall, the steam was dissipating. The vendor seemed to mutter something, followed by the soft thud of the steamer lid being replaced. No sound of hurried footsteps from Gu Zhixing. No shouts. Lu Chenzhou’s heart sank. This reaction wasn’t right. If Gu Zhixing had lost his target, there should at least have been a moment’s hesitation or searching. But outside, there was only silence. He didn’t wait any longer. He began moving quickly through the dark, narrow gap. The passage was cluttered with broken flowerpots, rotten planks, and rusty metal buckets. He had to sidestep, stride over, and duck under obstacles, yet his movements were fluid, as if he had practiced them countless times. The thirty-meter-long gap took him less than ten seconds to traverse. The alley connected to the exit was even more secluded, its ground slick with filthy water, the walls on both sides covered in moss. At the far end of the alley, the gradually growing clamor of the morning market could faintly be heard. Lu Chenzhou did not head toward the noise. Instead, he turned and slipped through a loosely closed, paint-peeling wooden door midway down the alley. Behind it was a dimly lit secondhand shop, crammed with all sorts of junk furniture, old appliances, towering piles of books, and assorted bottles and jars. The air was thick with the stale smell of mildew and dust. An old man dozed behind the counter, showing no reaction to someone entering. Lu Chenzhou quickly weaved through the chaotic piles of goods to the deepest part of the shop. There stood a dilapidated wooden door leading to a small backyard. A rusty padlock hung on the door, but the hinges were clearly well-used, the door frame edges worn smooth. He grasped the handle, twisted it very gently, and pushed inward— He slipped into the backyard. The yard was small, heaped with even more scrap. Against one wall was a rusted iron ladder leading up to an open, glassless window on the second floor. He didn’t climb the ladder. Instead, he strode quickly to the other side of the yard, where a low brick wall separated it from a wider alley beyond. He needed to confirm whether Gu Zhixing had followed, and how quickly. So, he crouched down, hiding behind a pile of old sofa cushions, and peered through a crack in the brick wall toward the entrance of the alley he had just come from. There was no movement inside the secondhand shop. The alley entrance was also empty. Then, after about two minutes—Gu Zhixing’s figure appeared at the mouth of the alley. He wasn’t running, nor had he even quickened his pace. He walked into the alley with the same steady, unhurried gait as before. His eyes swept over both sides. As he passed the loosely closed wooden door of the secondhand shop, his steps didn’t falter in the slightest, as if it were just an ordinary wall. But when he reached the middle of the alley, he stopped. Gu Zhixing lifted his head, adjusted his gold-rimmed glasses, and his gaze seemed to casually sweep over the secondhand shop’s faded, illegible signboard above the door, then glanced at the dim light seeping through the door crack. Then, he tilted his head slightly, as if listening. Inside the secondhand shop, there was only the old man’s muffled snoring and the rhythmic *tick-tock, tick-tock* of an old clock somewhere. For those ten seconds, Lu Chenzhou hid behind the backyard wall, his breathing suppressed to a minimum. He could hear the heavy, slow beat of his own heart in his chest, feel the fine layer of cold sweat that had broken out on the back of his neck, chilled by the morning breeze, causing a faint shiver. Gu Zhixing didn’t enter the secondhand shop. Instead, he continued walking deeper into the alley, toward the noisy end where the morning market was. His back soon disappeared around the alley’s It wasn't the typical musty smell of old buildings, nor the decaying odor of household waste. It was the residual scent of some kind of chemical solvent, mixed with the almost cloyingly pungent, uniquely sharp smell of fresh latex paint. Lu Chenzhou stopped at the turn of the staircase, his left hand instinctively pressing against his pocket—inside was the encrypted note obtained from Zhou Zhengping, bearing only one hastily scribbled address: Room West, Third Floor, No. 47 Xiangyang Road, Old District North. "Something wrong?" Gu Zhixing's voice came from half a step behind, steady and devoid of any discernible emotion. Lu Chenzhou didn't turn around. His gaze swept over the steps—the edges of the concrete stairs bore faint drag marks, not from furniture, more like shallow impressions left by the friction of some soft container. The marks were fresh; the exposed concrete color where the dust had been pushed aside was a shade lighter than the surrounding area. "The dust distribution is off," he said, his tone as even as if discussing the weather. "This building has at least six floors, four units per floor. But the dust thickness on the steps above the third floor increases noticeably." Gu Zhixing was silent for two seconds. "Meaning, only the third floor has seen frequent up-and-down traffic recently?" "More than frequent." Lu Chenzhou stepped onto the final stair, standing at the entrance to the third-floor corridor. The doors on both sides of the hallway were tightly shut, the windowpanes covered in a thick layer of dust. Only the doorknob of the west unit's door had an abnormally bright metallic sheen. "It was concentrated moving. And—" The lock on the west unit's door was an old pin-tumbler lock, its core severely worn. Lu Chenzhou fished a paperclip from his pocket, straightened it, and pressed his fingertip against the edge of the keyhole to feel the position of the pins. The corner of his left eye began to twitch slightly, once, twice. The paperclip probed in, turned, and with a soft *click*... A wave of intense chemical odor hit him like an invisible wall. Lu Chenzhou's breath hitched for half a beat. It wasn't the emptiness left after moving out furniture; it was the emptiness of having life's traces utterly stripped away. The walls were a blinding white, the newly applied latex paint reflecting a uniform matte finish under the morning light. The floor was old terrazzo, but so clean it mirrored the reflection of the windows—no dust, no water stains, not even the imprints left by years of furniture placement, all ground away. A window was cracked open a slit; the wind blowing in stirred the almost invisible particles of paint mist suspended in the air. Sunlight slanted in from the east window, casting a straight beam of light across the empty room. Within the beam, dust particles danced frantically like startled plankton. "Seems the person you're looking for moved out quite thoroughly?" Gu Zhixing followed him in, the clear tap of his leather shoes echoing on the terrazzo floor. He stood at the doorway, not venturing further, his gaze behind gold-rimmed glasses slowly sweeping every corner of the room. Lu Chenzhou crouched down, lightly brushing the corner of the wall with the pad of his index finger. The wall surface was abnormally smooth. Ordinary painting would leave subtle textures from rollers or brushes, but here the wall was as flat as if industrially sprayed. He leaned in and sniffed—formaldehyde, benzene compounds, and a hint of... acetone? The smell of professional thinners. Not the ordinary paint a renovation crew would use. "The potential witness in Zhao Mingcheng's case," he stood up, his voice betraying no ripple of emotion, "according to the tip, rented here for three months. Looking at it now, either the tip was wrong, or—" "—this witness is extremely privacy-conscious. Leaving not a single biological trace after moving out." Gu Zhixing adjusted his glasses. "Professional cleaning services are quite common nowadays. Especially..." he paused, "some landlords require tenants to restore the unit to its original condition upon moving out." "Restore to original condition." Lu Chenzhou repeated the phrase, walking to the window. In the corner of the windowsill was a small, milky-white congealed spot, not yet fully dried. He scraped a bit off with his fingernail, rubbing it between his fingertips. It was highly viscous—high-grade wall repair paste. "Has Attorney Gu ever seen this kind of 'restoration'? Walls repainted, floors polished, even the accumulated dust in the window seams vacuumed clean. This isn't cleaning; this is..." Lu Chenzhou turned around. Sunlight shone from behind him, elongating his shadow and casting it onto the snow-white wall. The edges of the shadow were as sharp as if carved with “First, the cleanser doesn’t want anyone to find this person. Second, the cleanser wants to test whether anyone can discern something from this ‘empty room.’” Gu Zhixing smiled. It was a faint smile, barely moving the finest muscles at the corners of his mouth. “Mr. Lu has a vivid imagination. However, from what I know, it’s quite common for rental apartments with high turnover in the old city district to be simply repainted after being vacated. Landlords do it to rent to the next tenant as soon as possible.” “Common,” Lu Chenzhou nodded. “But after painting, ventilation is needed for at least three days for the formaldehyde concentration to drop to a safe level. The paint in this room was applied last night.” He walked over to the wall and pressed his palm flat against it. The surface was icy cold. “Latex paint needs two hours to dry to the touch, twenty-four hours to fully cure. The wall is completely dry now, but the solvent smell in the air is still this strong, meaning the windows were closed while painting, and only opened for ventilation afterward. The time…” He estimated the indoor temperature and humidity, “…is no more than twelve hours.” Gu Zhixing didn’t reply. He walked to another wall and also reached out to touch it. His movements were slow, as if sensing something. “The conclusion is,” Lu Chenzhou withdrew his hand, took a tissue from his pocket, and meticulously wiped his fingertips, which had no actual dust on them, “someone was here before us. Not the landlord, not ordinary cleaners. A professional team, with professional equipment, working late at night. They knew we were coming.” “Or,” Lu Chenzhou continued, “they knew ‘someone’ would come.” Lu Chenzhou leaned back in the passenger seat, watching the street scenes speeding past outside the window. The clutter of the old city district gradually gave way to neat rows of shops, then newly built residential buildings, their glass curtain walls reflecting the nine o’clock morning sun. The world appeared orderly and proper, like a parallel universe separate from the thoroughly erased room he had just left. Gu Zhixing drove steadily, his hands always positioned at ten and two on the steering wheel. At red lights, he would lightly tap the edge of the wheel with a fixed rhythm, as if silently counting something. “In the cases you’ve handled, have you ever encountered ‘professional site restoration’ services?” Gu Zhixing’s fingers paused briefly. “There’s no such classification in law. Cleaning is cleaning.” “But some cleaning,” Lu Chenzhou continued, his tone casual as if making conversation, “uses special solvents that can break down proteins in bloodstains. Some bring ultraviolet lamps to check for residual fluorescent reactions. And some… even scrape off a layer of the wall plaster.” “Mr. Lu seems quite familiar with these things,” Gu Zhixing remarked. “Required coursework in criminal investigation,” Lu Chenzhou said, his gaze falling on the rearview mirror, which reflected a small portion of Gu Zhixing’s profile. “The first principle of crime scene investigation is to identify whether the scene has been ‘processed.’ The more professional the processing, the more it shows that whoever is behind it doesn’t want you to know what happened there.” “So, regarding today’s scene,” Gu Zhixing turned on the indicator, and the car entered a tree-lined avenue, “does Mr. Lu consider it ‘professionally processed’?” “Yes,” Lu Chenzhou answered without hesitation. “And the timing was extremely precise. Professor Zhou gave me the lead at three o’clock yesterday afternoon. I decided to investigate first thing this morning—only one night in between. The other party completed the entire process of clearing out, painting, and cleaning within that single night. The efficiency is too high to be a spur-of-the-moment decision.” Gu Zhixing didn’t respond immediately. The car entered an underground parking garage, the dim lights sweeping past the windows one by one. The tires thudded dully over speed bumps. The car stopped, the engine turned off. The residual warmth of the engine slowly dissipated in the silence. “Mr. Lu,” Gu Zhixing unfastened his seatbelt but didn’t get out, “Shen Yansheng asked me to assist you in the investigation to clarify the cause of Mr. Zhao Mingcheng’s death. As for other matters… some fragmented clues from old cases, I suggest you not delve too deeply.” “Because some waters,” Gu Zhixing pushed the car door open, letting the cool air from the garage rush in, “are much deeper than they appear. Venturing in recklessly can easily lead to drowning.” Having said that, he got out of the car. The sound of the door closing echoed through the garage. Lu Chenzhou sat alone in the car, unmoving. The air conditioning had stopped, but the cold air was slowly seeping into Lu Chenzhou closed his eyes, letting the water beat against the nape of his neck. His skin gradually flushed red, his muscles slowly relaxing under the high temperature. This was the only moment today that truly belonged to himself—the bathroom door was closed, the sound of running water masked everything, no one was watching, no expressions needed to be concealed. He took a deep breath; water vapor entered his nostrils, carrying the cheap lavender scent of the shower gel. He dried his body and put on clean cotton pajamas. The mirror was fogged, reflecting only a blurred human silhouette. He wiped a clear patch with a towel and saw his own face: faint dark circles under his eyes, cheekbones slightly prominent from recent weight loss. The left corner of his eye was still twitching lightly, faster than usual. He stared at the mirror for a few seconds, then pushed open the bathroom door. A floor lamp was lit in the living room. Gu Zhixing sat on the sofa, flipping through a financial magazine. Hearing the movement, he looked up. His gaze, behind gold-rimmed glasses, lingered on Lu Chenzhou for a moment before returning to the magazine. "Still here?" Lu Chenzhou asked, drying his hair with a towel as he walked toward the kitchen. "Mr. Shen Yansheng instructed that I stay here for this period," Gu Zhixing closed the magazine. "The living room sofa can be unfolded into a bed. I won't disturb Mr. Lu's rest." Lu Chenzhou took two bottles of mineral water from the fridge and walked back to the living room. He placed one bottle on the coffee table in front of Gu Zhixing; the glass bottle bottom made a crisp clinking sound against the glass tabletop. Then he sat down in the single armchair opposite, unscrewed the other bottle, and took a large gulp. The water was ice-cold, sliding down his esophagus, causing a slight contraction in his stomach. "The security in the old city district isn't great," Lu Chenzhou began, his voice somewhat relaxed from the hot shower. "Especially in those old buildings—the surveillance cameras are just for show." "So, to complete such a professional cleanup operation overnight in a place like that," Lu Chenzhou took another sip of water, "requires not just money and manpower. It requires information—knowing who lives there, knowing who would go to investigate, knowing when to investigate. It also requires..." He paused. "Clearance." "Late-night moving, heavy-duty grinding machines, paint sprayers. These would all make noise, produce smells. But not a single household in the entire building came out to look. The neighbor next door this morning avoided eye contact, claiming ignorance to every question." Lu Chenzhou put down the water bottle. "Either they're afraid of trouble, or they were given a heads-up beforehand. I lean toward the latter." Gu Zhixing finally picked up the water bottle. But he didn't open it; instead, he rubbed the label on the bottle with his thumb. The plastic film made a faint rustling sound under his fingertips. "What I want to say," Lu Chenzhou leaned forward, elbows resting on his knees, "is that the cleanup force wasn't Shen Yan." The living room fell quiet. The halo from the floor lamp cast a warm yellow circle on the coffee table between them. Beyond the light, the corners of the room sank into dimness. In the distance, the sound of a late-night car passing by could be heard, tires rubbing against the road surface, approaching from afar and then fading away. "Because if it were Shen Yan," Lu Chenzhou said, "you wouldn't have let me near that building at all. You would have used various excuses to delay, prevaricate, or simply told me the lead was dead. But today, you cooperated fully throughout. Even when I tried to shake you off, what you displayed were professional tracking skills, not obstruction." "Shen Yanqing sent you to follow me, nominally to assist, but in reality, to monitor. But there are two types of monitoring: one is to prevent me from contacting what I shouldn't, and the other is... to observe what I *will* contact, and what happens after that contact." "What happened today falls into the latter category." Lu Chenzhou leaned back against the sofa, his tone becoming very light. "I took you to investigate a lead regarding a witness in an old case, and the lead was precisely erased by a third party right before my eyes. You saw the entire process, saw my reaction, and saw the professionalism of the cleanup. Now, you will report all of this to Shen Yanqing. And he..." Gu Zhixing slowly unscrewed the water bottle. He took a sip of water; the sound of swallowing was especially clear in the silence. "Mr. Shen Yansheng is only concerned with the truth of Zhao Mingcheng's case," he said, his voice steady as usual. " “I gave you water, you accepted it, and you drank it.” Lu Chenzhou turned around. “In investigative psychology, this means that at least at this moment, subconsciously, you don’t consider me an enemy. Or, you don’t think I need to be guarded against to the extent of not even drinking a mouthful of water.” Gu Zhixing straightened up and looked at him. The light reflected two tiny points of light on his glasses. “It means,” Lu Chenzhou walked back to the coffee table and picked up his own bottle of water, which was still half full, “that regarding today’s cleanup, Shen Yan might have been aware, but he was not necessarily the executor. And you… you were observing, assessing, but you did not stop me from investigating further. Why?” The two men looked at each other. The air seemed to solidify, with only the almost inaudible hum of electric current from the floor lamp’s bulb. “Mr. Lu,” he said, “with some questions, knowing the answer isn’t necessarily a good thing. Just like some bodies of water, you only need to know they are deep; you don’t need to personally measure their depth. Mr. Shen Yansheng hired you to clarify the cause of Mr. Zhao Mingcheng’s death. As long as you focus on that, other matters… will naturally be handled by those who should handle them.” “Those who should handle them.” Lu Chenzhou repeated. “Like that professional cleanup team today?” Gu Zhixing did not deny it. He walked to the floor lamp and switched it of