The "Survival on the Train" game has bugs, it's really laggy!

The ten-minute preparation was nearing its end.

The engines of the Devourer were idling, their sound muffled within the engine compartment. Wang Hu tightened the two removed bushings again; the lingering smell of burnt metal from the welding torch hadn't dissipated. Tang Lan walked around carriage 013, checking the restraints on each wounded soldier. The veteran mechanic stuffed the last bit of dry gauze into the side pocket of his medical kit and zipped it up.

Little Fire lay on the control panel, its tail taut. Its paws scratched the panel twice; the old terminal screen was divided into three columns: the left side displayed the pressure sensor readings below the third section of the base plate, the middle showed the rail surface vibration frequency, and the right side displayed the airflow curve of the ventilation duct. All three curves fluctuated slowly, like breathing.

Su Yuan stood up from the driver's seat and walked to the side door. Li Wei, wrapped in the old blanket, was huddled in the corner by the door frame, his face still sallow. He looked up at Su Yuan and his lips moved.

"Go on," Su Yuan said.

Li Wei swallowed hard. His throat was dry and rattling. "Every day at 3:07 AM, there's a sound from below." He spoke softly, as if afraid of disturbing something. "It's not regular every day, but the time is within ten minutes of each other. The sound is muffled, coming up from the floor, and the whole carriage can feel it."

No one in the carriage responded.

Wang Hu tightened the last bolt and tossed the wrench into the toolbox. The metallic clanging sounded crisp in the quiet carriage.

"Before they fell asleep," Li Wei stared at the ground, "they all said one thing to me."

Su Yuan waited.

"They said there's something listening under the floorboards." Li Wei's fingers dug into the edge of the blanket. "It's not a system, it's not a machine. It's just... there's something down there, motionless. But it can hear what's coming from above. They can sense it."

A cough came from the direction of carriage 013, which was muffled and quickly disappeared.

Su Yuan turned and walked back to the driver's seat, sitting down. His right hand rested on the leather cover of the steering wheel.

"Small fire."

"exist."

"Pull up the logs of the third base plate sensor and only look at the trigger records."

With a swipe of its little claw, a timeline popped up in the lower right corner of the screen. The trigger seventeen minutes ago was marked in red, and the predicted trigger timestamps afterward were marked with gray dashed lines.

"There are eleven minutes left until the predicted trigger for the pre-generated logs," Xiao Huo said.

Su Yuan glanced at the timestamp. Then he looked at the track diagram. The downrail had a bend two kilometers ahead, then led straight to the fork. To the left of the fork was the signal source for the third carriage, and to the right was the living power source—now mostly blocked by the wreckage of the fourth carriage, but the signal was still beating.

"Let's go," he said.

The engine revved up. The front wheels of the Devourer pressed back onto the rails, the wet, grinding sound of the dark red fascia being crushed echoing from the bottom of the carriage. The third carriage was suspended, its door still open. Inside, the twelve sleeping Earthlings lay on reclining chairs, their chests rising and falling almost imperceptibly.

Wang Hu squatted by the side door, holding a can of white chalk dust. He leaned out and smeared some chalk dust on the outer beam of the third carriage. The chalk dust left a noticeable white mark on the damp metal surface.

"Mark the point." Wang Hu pulled back and said to Su Yuan, "We'll observe the vibration shift later."

The veteran mechanic came over from car number 013, carrying a half-full glass of water. He walked to the side door of the third carriage, squatted down, and gently placed the glass on the carriage floor near the door. Then he took out three more identical glasses and placed them in the other three corners.

Wang Hu looked at it. "Will this work?"

"A quick shake will tell," the veteran mechanic stood up. "More sensitive than a sensor."

Xiao Huo pulled a thin wire from under the control panel and tied a hexagonal nut to it. He attached one end of the wire to the handrail above the side door, with the nut hanging down at just the center of the carriage floor.

"A simple pendulum," Xiao Huo said. "If the deflection exceeds two centimeters, the base plate will be tilted."

Su Yuan stared at the three curves on the screen. The vibration frequency of the rail surface was very stable. The airflow in the ventilation duct fluctuated slightly, and the thermal pulse occurred every forty-two seconds. The pressure sensor readings fluctuated slowly within the green safe range.

The car speed was reduced to six kilometers per hour.

The sound of the wheels rolling over the fascia became viscous. The dark red tissue gleamed wetly under the headlights, and in some places it had grown onto the sides of the sleepers, like congealed scabs.

Tang Lan's voice came through communication channel 013: "Second check of all personnel's immobilization straps completed. The wounded's vital signs are stable."

Su Yuan didn't reply. His gaze fell on the timestamp in the corner of the screen.

Eight minutes left.

The carriage was so quiet you could hear the hum of the ventilation ducts. Someone whispered something over the 013 end, but the sound was absorbed by the duct walls, leaving only a faint hissing sound.

Li Wei was still huddled by the door. His fingers unconsciously tapped the edge of the blanket. Tap. Tap tap. The rhythm was chaotic and irregular.

Six minutes left.

Su Yuan suddenly spoke. "Wang Hu."

"exist."

"Loosen the main winch cable halfway. Leave a 20-meter allowance, and make sure the hooks don't get caught."

Wang Hu paused for a moment, but didn't ask. He climbed to the back of the vehicle, turned on the winch control panel, the motor spun a few times, the steel cable slackened, and the hook dangled half a meter off the ground.

Four minutes left.

The veteran mechanic walked to the side door and checked the position of the water glass again. The water surface was very flat, with only the slightest sloshing.

Three minutes left.

The fascia of the orbital facet suddenly moved.

It wasn't the slow, creeping movement we'd seen before. Instead, several dark red fascia ropes, thicker than fingers, suddenly emerged from the gap at the bottom of the third carriage and wrapped around the two wheelsets on the left side of the carriage.

The carriage shook slightly.

The old mechanic placed a water glass in the front left corner, and the water surface rippled.

On the old terminal screen, the pressure sensor reading jumped. It skipped from the edge of the green zone and bounced directly into the yellow zone.

The broadcast malfunctioned. It wasn't the previous aged, synthesized voice; it was a rough system tone, accompanied by the screeching of overloaded relays. "Pressure distribution anomaly! Nerve gas safety deactivated 20%!"

There was a moment of deathly silence in the carriage.

Someone cursed in carriage 013, their voice trembling. Several young survivors instinctively reached for the cutting tools at their waists.

The announcement continued: "Please immediately isolate the third carriage in the lead car. Otherwise, the entire train will be considered contaminated, and a full purification procedure will be initiated."

Li Wei's face turned pale. He gripped the doorframe, his knuckles white. "The third time... last time it rang for the third time, and the person inside..."

He didn't finish speaking.

Communication 013 went off. Tang Lan's voice was low: "Su Yuan, the stress on the tail beam has increased by fifteen percent. Those fascia are lifting the carriage."

Su Yuan didn't reply. He stared at the numbers flashing on the screen.

Toxic gas insurance: 20%.

Pressure sensor reading: middle of the yellow zone.

Ventilation duct heat pulse: 38 seconds remaining.

One minute left.

A dull thud came from under the carriage. It wasn't a metallic clang; something springy had struck from below. The entire carriage shook.

The six reclining seats near the front of the vehicle simultaneously rose slightly by two or three centimeters, revealing a gap between the seat surface and the floor.

The old mechanic placed a water glass in the back left corner; the water surface exploded into a ring, and half of the water splashed out.

Toxic gas insurance: 28%.

The announcement repeated: "Isolate the third carriage immediately."

Wang Hu gripped the wrench tightly. He stood by the side door, staring at the dark red fascia wrapped around the wheels. The rope was tightening, and the metal rims creaked under pressure.

Tang Lan's voice came again. "Su Yuan, if we delay for another twenty seconds, the tail boom of train 013 will break. If we uncouple now, I can save the lead car and the third train." She paused, "The choice is yours."

Several young survivors in the carriage looked up towards the cockpit of the Devourer. Some of them moved their lips but didn't speak.

Lu Mingyuan's voice came through the control room channel. The keyboard was being typed rapidly. "Su Yuan, the stress model is done. If the base plate is lifted twice more, the gas cylinder will enter an irreversible release process. Decoupling the third section is currently the only safe option."

He spoke very quickly, and every word was precisely chosen.

The carriage became even quieter. Suddenly, the humming of the ventilation ducts became very loud.

Su Yuan's hands remained on the steering wheel, motionless. His gaze shifted from the screen to the outside of the windshield. Inside the open door of the third carriage, the sleeping Blue Star personnel remained motionless. The railings of the reclining seats were upright, and the restraints were fastened. Their breathing was shallow.

"I won't take it off," Su Yuan said.

The keyboard clicks on Lu Mingyuan's end stopped. After two seconds, his voice was dry: "Mathematics doesn't lie."

"You calculated the static forces." Su Yuan released the steering wheel, got up and walked to the side door. He glanced at the dark red fascia wrapped around the wheelsets, and then at the white chalk mark on the outer beam of the third carriage.

"Wang Hu, Cold Spring Pipe."

Wang Hu had already dragged the pipe over. He unscrewed the connector, and two drops of cold water dripped from the pipe opening.

"Wait for my command," Su Yuan said. He crouched down, his fingers pressing against the outer frame of the third carriage. The metal was cool, and through a layer of rust and grime, he could feel a slight vibration. It wasn't coming from the carriage itself, but from underneath.

He closed his eyes.

The heat pulse in the ventilation duct will occur once every 22 seconds.

Vibration frequency of the carriage floor: 0.5 Hz.

Fascial tightening rhythm: irregular, but roughly synchronized with the vibration of the base plate.

Su Yuan opened his eyes. "Tang Lan."

"exist."

"Number 013 is partially locked. The tracks rotate a quarter turn, then lock. Once every seven seconds."

Tang Lan didn't ask why. "A half-circle lock, seven seconds per round."

"right."

"Wang Hu. Align the cold spring pipe with the left side of the third wheel section. Pour when the fascia tightens, stop when it loosens."

Wang Hu nodded.

Su Yuan walked back to the driver's seat and sat down. His right hand rested on the accelerator, and his left hand was next to the winch control button.

On the old terminal screen, the gas safety figure remained at 32%. It didn't rise any further.

Timestamp: Forty-seven seconds until the next prediction is triggered.

Su Yuan pressed the accelerator. Very lightly, the engine speed only increased by half a gear. The steel cable was slightly taut. At the same time, his left hand pressed the winch reel button. The winch motor turned, but instead of pulling forward—it applied a lateral force diagonally to the side.

A metallic groan came from the third carriage. The outer frame of the carriage was slightly deformed, and the position marked with white chalk was dented in half a millimeter.

At the same time, Wang Hu leaned out of the car and aimed the cold spring water pipe at the dark red fascia that was most tightly wrapped around the left wheel arch, and poured it on it.

Cold water splattered onto the damp tissue. Steam rose. The fascia contracted slightly, and the grip loosened a little.

Just this once.

The old mechanic placed the water glass in the front left corner; the water sloshed around for a moment, then returned to calm.

On the old terminal, the pressure sensor reading dropped one notch. It receded from the middle of the yellow zone to the edge of the yellow zone.

Toxic gas insurance: 31%.

effective.

Little Fire called out. The tip of its tail twitched.

Lu Mingyuan leaned forward in the control room, staring at the screen. He tapped his fingers twice on the edge of the console.

Section 2. Seven-second countdown.

Su Yuan repeated the operation. Throttle, winch pulled horizontally, Wang Hu sprayed water. The three men completed their actions within seven seconds, with an error of no more than 0.3 seconds. This time, Su Yuan pulled horizontally at a greater angle, the steel cable forming an angle of nearly thirty degrees with the carriage.

The outer frame of the third carriage has dented in a little more. The chalk markings are crooked.

Wang Hu's hose followed even more precisely. Cold water was poured directly onto the contact point between the fascia and the rim.

Click.

A soft cracking sound. It wasn't metal; it was the sound of some kind of fibrous tissue breaking.

Toxic gas insurance: 29 percent.

In carriage 013, someone took a breath. It was very soft, but it could be heard clearly in the quiet carriage.

Li Wei, peering through the crack in the door in the third section, pressed his forehead against the door panel, his eyes closed. His lips were trembling.

Section 3. Five-second countdown.

Su Yuan didn't wait the full seven seconds. He started two seconds early.

This time, the accelerator was pressed a little harder, and the engine revved to the second gear threshold. The winch pulled at a greater angle, and the steel cable was taut. Wang Hu's water pipe was aimed at the root of the fascia—the area most vulnerable to sudden cooling.

The moment the cold water was poured on him, Su Yuan released the winch cable reel button with his left hand and simultaneously pressed the clutch with his right foot.

The winch stopped.

But the inertia remained. The lateral pulling force was transmitted through the steel cable to the outer frame of the third carriage, pulling the already deformed metal inward a little further.

Then Wang Hu's cold water arrived.

Thermal expansion and contraction.

Snapped.

The three dark red tendons wrapped around the left wheelset broke off simultaneously at their roots. A small amount of dark red liquid spurted from the break, splashing onto the rail surface with a hissing sound.

The pressure sensor reading plummeted, dropping directly from the yellow edge back into the green zone.

Toxic gas insurance: 21%.

The broadcast was interrupted. The system voice repeated half a syllable—"Please temporarily call me—"—and then cut off.

Inside the carriage, six reclining chairs slowly lowered back onto the floor. The gap between the chair seats and the floor disappeared.

The water glasses that the old mechanic had placed in the four corners all returned to calm.

The nut-shaped pendulum hangs there, motionless.

In carriage 013, several young survivors put down their cutting tools. Some slumped to the ground, their shoulders trembling.

Tang Lan's voice came through the communicator. It was flat, but each word was emphasized. "All members of Unit 013, breathe in rhythm with the lead vehicle."

Outside the carriage, Wang Hu shrank back and closed the side door. He leaned against the doorframe, catching his breath. "Damn, it moved."

Su Yuan didn't reply. He stared at the screen. The gas safety figures were still slowly decreasing: 19%, 18%, 16%.

The heat pulse for the ventilation duct will occur once every eleven seconds.

Su Yuan released the accelerator, and the engine speed dropped to idle. He leaned back in his seat, his right hand resting on the steering wheel cover, without moving.

Timestamp: Eight seconds until prediction trigger.

Xiao Huo's ears flattened. "The readings are stable. No signs of a secondary trigger."

Su Yuan's gaze fell on the corner of the screen. There were three curves: pressure sensor readings, rail vibration readings, and ventilation duct airflow readings. The first two were stable. The third—the ventilation duct thermal pulse curve—was fluctuating according to a 42-second cycle.

But Su Yuan stared at one of the peaks.

The peak was delayed by 0.8 seconds compared to a normal thermal pulse. The amplitude was very small, almost drowned out by the background noise. It was practically invisible unless the three curves were superimposed for comparison.

"Keep it low," Su Yuan said.

"exist."

"The thermal pulse curve of the ventilation duct shows all peaks with a delay of more than 0.5 seconds."

With a flick of its little claw, the curve on the screen was magnified, and several subtle anomalies were marked with red circles.

Su Yuan looked at the red circles. They weren't randomly distributed. Each delay occurred after a tiny fluctuation in the pressure sensor reading—a fluctuation so small, less than 0.5%, well within the safe range, that the system wouldn't alarm.

But fluctuations do exist.

"We overlap and compare the time points of all the delayed peaks with the time points of the slight fluctuations in the pressure sensor," Su Yuan said.

Little Fire's claws moved swiftly. Two sets of data overlapped on the screen. The timestamps were accurate to milliseconds.

The delayed peak is 0.8 seconds slower than the tiny fluctuation of the pressure sensor each time.

Lu Mingyuan's voice came from the control room, sounding somewhat urgent: "Su Yuan, the pressure sensor has turned green again, the risk of decoupling has been eliminated. I suggest continuing the descent."

Su Yuan didn't respond. He stared at the two overlapping curves.

The thermal pulse delay in the ventilation duct is 0.8 seconds.

The pressure sensor shows slight fluctuations.

It always happens in the right-hand area of ​​the third carriage.

Depth: Three meters.

Su Yuan suddenly stood up. "Wang Hu."

"exist."

"Open the inspection cover on the right side of the third carriage, near the rear."

Wang Hu paused for a moment. "Which one?"

"The third one. Counting from front to back." Su Yuan pointed to the diagram of the carriage structure on the screen. "The area under that cover is empty and doesn't bear any weight."

Wang Hu jumped off the train carrying his toolbox. The veteran mechanic followed behind. The two walked to the right side of the third carriage and squatted down. The rail fascia was limp but still stuck to the metal surface; stepping on it would sink halfway into the sole of your shoe.

Wang Hu found the inspection cover. The four fixing bolts were rusted shut. He swung his sledgehammer and smashed it down, the bolt snapping in two. The second, the third... The fourth was stuck, the old mechanic used a crowbar to hold it in place, but Wang Hu finished it off with another blow.

The cover was lifted. It was dark underneath. Shining a flashlight inside, you could see a thick layer of dust and cobwebs, along with a few rusted pipes. Further down, it was empty—there was about a three-meter height difference between the carriage floor and the actual rail surface below.

A cold wind rushed in from the cave entrance. It carried a musty, rusty smell, and something else—a faint, sweet smell of nutrient solution mixed with the stench of some kind of decaying organic matter.

Wang Hu shone his flashlight downwards. The beam swept across the darkness, illuminating a section of metal track about two meters below. It was an old-fashioned, narrow track, heavily rusted, but still intact. A small cart frame sat on the track—very narrow, less than half a meter wide, with solid wheels and no power.

The frame is empty.

However, there were drag marks on the rails next to the frame. A layer of dust had been rubbed away, revealing scratches on the metal underneath. The scratches were very fresh.

Su Yuan stood by the side door of the driver's cab, looking at the opening. He didn't get down.

"Turn the fire down and connect the winch claw to the low-power angled light."

Xiao Huo did as instructed. He untied the hook from the winch, attached a thin steel cable with a small waterproof lamp tied to the end. Wang Hu took the hook and slowly lowered it into the hole.

The light swayed and sank slowly. Two meters. Two and a half meters.

The grappling hook made a soft click as it touched the metal rail. Wang Hu adjusted the angle, directing the light forward.

The narrow track stretched forward and disappeared into the darkness. It ran horizontally beneath the third carriage, across the bottom of the sleepers.

The light swept back.

It swept to the side of the small car frame.

Wang Hu's hand trembled slightly.

The light shone on a hand.

A hand, so thin it was just skin and bones, reached out from the darkness and rested on the edge of the narrow railing. The knuckles were large, the skin dry and brittle, clinging to the bone. The nails were long, several broken.

The hand was alive. The fingers were trembling slightly.

Su Yuan's voice came from above. "Wang Hu."

"Yes." Wang Hu swallowed.

"Don't move the light. Slowly move it over to illuminate the whole thing."

Wang Hu steadied his hand. The light was moved ten centimeters towards the hand.

The camera captured his arms. Forearms, elbows, and upper arms. He was wearing a tattered Blue Star field uniform, the cuffs torn into strips of cloth. His arms were thin, like withered branches.

Further on.

Shoulders. Neck. Half of the face.

It was a woman. Her face was thin, with prominent cheekbones and deep-set eyes. Her eyes were closed, and her lips were chapped. A black square box was pressed against her chest, with two thin lines running down the seams of her clothes and disappearing into the darkness.

There is an indicator light on the side of the box. The green light flashes faintly and steadily.

Heart rate transponder.

The woman's hand was still resting on the edge of the tracks. Her fingers were trembling, very slightly, but persistently.

Su Yuan stood there, looking at the hole. "Is there anything else next to her?"

Wang Hu shone the light on the woman's side. It illuminated a metal box, half-buried in the dust. The box had knobs and dials on its surface, and a flexible tube on its side, the other end of which was connected to a rubber airbag.

Old-style pressure simulation box.

It is used to simulate pressure signals of a specific frequency and amplitude to fool pressure sensors.

The woman lay there, and every now and then, her body would rise and fall slightly due to breathing or involuntary twitches. These fluctuations were converted into vital signs by a heart rate transponder and transmitted through circuitry on the base plate to pressure sensors.

At the same time, the pressure simulation box was set to a specific mode to create a regular "heartbeat"-like fluctuation in the sensor readings in conjunction with her vital signs.

Each fluctuation is identified by the system as a "biological signal that is neither caused by human movement nor mechanical vibration".

Each time, the gas safety measures are pushed one step closer to the release process.

Li Wei guarded this place for fourteen years. Every day at 3:07 AM, a sound would ring out from below.

That's not a monster.

It was this woman. Tied to a narrow-gauge train, tucked under the floor of the third carriage, she was used as a living trigger. She was alive, but unable to wake up. Her heartbeat, her breath, every spasm of hers, were repeatedly triggering the murderous program.

Inside the carriage, the veteran mechanic brought over the half-bottle of iodine and the last few rolls of bandage. Tang Lan jumped down from compartment 013, carrying an emergency light. She walked to the edge of the tunnel, glanced down, and said nothing.

Su Yuan squatted down and looked at the hand resting on the edge of the track.

"Wang Hu, lower the grappling hook. Gently, don't touch her."

Wang Hu operated the winch, and the hook slowly sank to the woman's side. The light shone on her profile.

Her lips moved. Very softly, as if she were saying something. But no sound came out.

Su Yuan stared at her lips for a few seconds.

"She's talking about 'water'," he said.

The old mechanic unscrewed his water bottle. It still contained about half a bottle of warm water. He handed it to Wang Hu.

Wang Hu tied the kettle to the hook and slowly lowered it. The spout was aimed at the woman's chapped lips. A few drops of warm water were dripped onto them.

The woman's throat moved slightly. The swallowing motion was faint, but present.

Her fingers curled up slightly.

The steel cable that had caught the hook was gripped.

Then, she tapped the steel cable three times with her fingers.

Short and rapid. Not Morse code. It's random tapping. It's the last bit of strength a person has before death, trying to make some sound.

After she finished tapping, her hand relaxed. Her fingers drooped, resting on the edge of the track, and stopped moving. But the indicator light on her chest remained lit. The green light flashed steadily.

The heart rate transponder is still working.

Su Yuan stood up. "Wang Hu, the old mechanic. Get ready to pull her up. Be slow, little by little. Don't pull, don't shake."

He looked at Xiao Huo. "Contact Lu Mingyuan. Have him calculate: if the heart rate transponder is disconnected, and an alternative signal source is connected to the base plate sensor, what is the reaction time of the gas safety device?"

Little Fire's claws moved rapidly across the control panel.

Lu Mingyuan's voice came back almost immediately. "The alternative signal source must simulate the bioelectric characteristics of the same frequency and amplitude. If the duration exceeds three minutes, the system will perform a secondary verification. If the verification fails, the gas safety will jump directly to 100%."

Su Yuan didn't reply. He stared at the woman below the cave entrance.

"Prepare two plans," Su Yuan said. "First, after pulling him up, connect the repeater to the warm water bag so the sensors can continue to read stable vital signs. Second—"

He paused for a moment.

"If the first set fails, I will directly remove the base plate sensor."

The carriage was silent for a second.

Wang Hu and the veteran mechanic exchanged a glance. The veteran mechanic nodded. "Take your time."

The steel cable of the hook began to tighten. Inch by inch.

The woman was slowly pulled out of the darkness. Her body was light, lighter than an adult's. The wheels of the narrow-gauge cart screeched against the tracks, but Wang Hu controlled the force, keeping the cart and her body rising in sync.

Two meters. Two and a half meters.

Her head emerged from the hole. Her face was pale and bloodless. Her eyes were still closed, but her eyelids were trembling slightly.

Tang Lan crouched down and placed her hand on the side of her neck. After a few seconds, she looked up. "The pulse is weak but steady. No fever. Like she's under deep sedation."

three meters.

Her entire body was dragged out of the hole and placed on the tracks next to the third carriage. The veteran mechanic immediately rushed forward and covered her with a blanket. Tang Lan opened the first-aid kit, took out a glucose injection, skillfully located the withered vein in her arm, and injected half of it.

The woman's throat moved again.

Su Yuan squatted down beside her, his gaze fixed on the black box on her chest. A heart rate transponder. Two thin wires extended from the side of the box, one connected to an electrode pad attached to her chest, and the other… the other connected to a junction box under the floor of the carriage.

Su Yuan reached out and pinched the thin wire connected to the power strip.

"Keep the timer on low heat."

"start."

Su Yuan pulled out the thin thread.

One second. Two seconds.

On the old terminal screen, the pressure sensor readings began to fluctuate. At first, there were slight fluctuations, then the amplitude increased.

Toxic gas insurance: 21%.

Twenty-five percent.

Thirty percent.

Someone in the carriage gasped.

Su Yuan didn't move. He took an empty rubber IV bag from Tang Lan's first aid kit, filled it halfway with warm water, and tied the bag tightly. Then he removed the electrodes from the heart rate transducer from the woman's chest and attached them to the face of the warm water bag.

The warm water inside the rubber bag simulates weak, regular temperature fluctuations.

The electrode pads convert this fluctuation into bioelectrical signals.

The signal is transmitted back to the terminal block under the floor of the carriage via a thin wire.

The pressure sensor readings stopped fluctuating and began to decrease steadily.

Poison gas insurance: 28%. 25%. 22%. 19%. 15%.

All the way down.

It finally stopped at eight percent.

Green safe zone.

The broadcast didn't ring. The system voice remained silent.

Inside the carriage, the six reclining chairs remained motionless. The sleeping Earthlings lay quietly in their seats.

The old mechanic wrapped the blanket tightly around the woman. Tang Lan was checking her injuries, her movements very gentle.

Wang Hu stood at the edge of the tunnel, looking down. The narrow-gauge train was still on the tracks, empty. Below the floor of the carriage, in three meters of darkness, there was nothing.

Only the logs at the very bottom of the old terminal screen have an additional line.

"Third section base plate pressure sensor: Signal source switched. New signal source: external simulator. Biometric matching accuracy: 97%. Continuously stable."

"Determination: Threat neutralized."

"This trigger point has entered a dormant state."

Su Yuan stood up and walked to the woman's side. Her eyes were still closed, but her breathing was a little deeper than before. Tang Lan handed her the half-full bottle of water, and Wang Hu carefully lifted her head, letting the spout touch her lips.

The woman swallowed a few times. Then, her eyelids fluttered open a crack.

The eyes were unfocused. Cloudy and dull, as if veiled in mist.

But her lips moved.

The sound was very soft, a breathy whisper, almost inaudible. Wang Hu leaned closer to listen.

"Don't... go down the left path..."

The woman said.

Each word was difficult to pronounce, but each syllable was clear as it was squeezed out of the throat.

"The left route... isn't to the outer ring road..."

She took a breath, her chest heaving.

"Go...feed it."

After saying that, she closed her eyes again. Her head rested on Wang Hu's arm, and she stopped moving. But her chest was still rising and falling. She was still alive.

No one spoke in the carriage.

Su Yuan stared at her for three seconds. Then he stood up and walked back to the driver's seat of the Devourer.

The old terminal screen was still lit. The orbital diagram was in the lower right corner. Behind the right-line entrance, which had been blocked by the debris from the fourth section, a new line had now appeared.

Very fine, gray, no markings.

Parallel to the right line, right below the current downward track where the Devourer is located.

Maintenance rail.

Su Yuan stared at that line.

At the same moment, a series of sounds came from under the carriage, in the darkness three meters deep.

It wasn't a heartbeat. It wasn't a confrontation.

It was the sound of metal wheels rolling over the tracks. Very light, very rhythmic, rolling along the surface. A short train, without lights, without power, was moving.

It followed them down slowly and parallel to the bottom of the Devourer.