Lin Wei stared at the notebook in his hands, the dust of decades coating its old cloth cover.
Lin Cheng.
His father's name.
Not a common name.Not a coincidence.
His throat tightened, but he forced air back into his lungs and flicked on his helmet light.The underground cavity glowed dimly, revealing the pump, the ancient stones, and the truth buried beneath a Siheyuan.
He opened the notebook.
The First Page
The handwriting struck him immediately—
Precise.Methodical.Engineer's script.
Lines of calculations.Load distributions.Stress vectors.Material aging curves.
And beneath them, a sentence:
"If someone is reading this, then the city has not learned."
Lin Wei's pulse hammered.
He turned the page.
A Warning From the Past
"My name is Lin Cheng. I write this knowing I may not see another sunrise."
Lin Wei's breath hitched.
The page continued:
"Years ago, I uncovered a structural criminal syndicate operating through official channels.They hid defects. They falsified reports.They sold collapses."
Lin Wei's blood went cold.
"When I opposed them, they threatened my family."
He clenched the page so hard it almost tore.
"I sabotaged one of their illegal projects to prevent a collapse disaster—only to be framed for it."
A tremble ran through his body.
"They sent someone after me.Someone brilliant.Someone monstrous."
Lin Wei whispered:
"…The saboteur…"
He turned the page.
The Mentor in the Shadows
"His name was Zhao Ruitian.""An underground structural theorist. A prodigy with no conscience.""He believed structural engineering should be a crucible—testing who deserves to live."
Lin Wei's hands shook.
"He told me that collapse is the purest form of truth."
Lin Wei's stomach twisted.
"He said I had potential.He wanted me to join him."
Lin Cheng had written a single, simple response beneath that line:
"I refused."
Lin Wei closed his eyes.
His father…had faced the same man.
"Zhao Ruitian swore he would test me.""He left clues. Riddles. Threats.""He turned structures into traps."
Lin Wei felt sick.
This wasn't random.This wasn't coincidence.This nightmare began long before he was born.
He turned the page.
The Sinister Prophesy
"If my son ever finds this notebook—"
Lin Wei froze.
Liu Fang's voice crackled suddenly in his earpiece:
"Lin Wei? Are you okay? Your vitals spiked—what's happening down there?"
He swallowed hard.
"I found… something."He forced his voice steady."I'm alright. Keep everyone away from the courtyard. I'm almost done."
Her breath steadied slightly.
"Be careful."
He returned to the page.
"If my son ever finds this notebook, it means Zhao Ruitian has returned."
Lin Wei's heartbeat thundered in his ears.
"He will test you.He will push you.He will hunt you."
Lin Wei gripped the notebook tighter.
"And he will watch the people you love."
His breath froze in his lungs.
"Especially the girl."
Lin Wei nearly dropped the book.
The girl…?
Did his father mean—
No.Impossible.
His father died when Lin Wei was eight.
He couldn't have known Liu Fang.
Unless—the "girl" meant something else.A pattern.A prediction.
Lin Wei turned the page roughly.
The Final Message
The last page was short.
Almost hurried.
"Zhao Ruitian believes only those forged in pressure deserve to save lives.""He will give trials.""Five of them."
Lin Wei inhaled sharply.
Five.
Just like the system.
"I set a failsafe beneath this courtyard.If you find it, it means Trial Three is his."
Lin Wei looked to the pump.His father had anticipated this exact event.
He read the final line.
"Son—If you face him…do not try to beat him at his game."
The ink smeared slightly, as if Lin Cheng's hand had shaken.
"Break the game."
Aboveground — A Sudden Shift
"LIN WEI!"
Liu Fang's scream blasted through the comm.
He jerked upward, hitting his head on the beam.
"What?!"
"The wall—it's moving!"
Master Yu shouted behind her:
"The pump just increased output! Pressure is rising!"
Old Zhang:
"The retaining wall is bulging—this is minutes from failure!"
Director Li:
"LIN WEI! Whatever is down there—shut it down NOW!"
Lin Wei snapped back to the pump.
His fingers flew across the casing.Twist.Press.Disconnect.Assess flow direction.
The pump wasn't just flooding—
It was drawing groundwater AND injecting foreign pressure fluid.
A hybrid sabotage technique.
Zhao Ruitian's signature.
Lin Wei grabbed the main valve and twisted.
It resisted.
He gritted his teeth and used all his strength.
The pipe squealed.
The pump whined.
Then—
CRACK!
The valve snapped open.A spray of water exploded outward.
The pressure dropped instantly.
And aboveground—
The vibrations halted.
Relief hit Lin Wei like a wave.
Then—
A soft metallic sound echoed behind him.
He spun.
The flashlight beam caught something on the far wall.
Something scratched into the stone.
Fresh.New.
A single sentence:
"Trial Four begins when you step outside."
Lin Wei's blood ran ice cold.
He crawled out of the underground cavity.
Emerging into the courtyard, mud-covered, soaked, gripping the notebook like a lifeline.
Liu Fang rushed to him.
"Lin Wei! Are you okay? What happened? What is that book?"
He held her gaze.
And finally spoke the truth:
"The saboteur knew my father."
She froze.
"He tried to recruit him."Lin Wei's voice was cold."And now he's trying to recruit me."
The entire team went silent.
Old Zhang whispered:
"…So this is personal."
Lin Wei shook his head.
"No. Not personal."
He stared at the cracked courtyard tiles.
"This is legacy."
He looked up.
His voice darkened:
"And Trial Four starts now."