Three days had passed since Yoe Choin's journey. Namgung Shiri and his entourage met at the western canyon.
Yoe Choin, in the form of Moen Kang Yo, stood on a podium he had personally constructed with millimeter precision. His glowing blue eyes scanned the twenty people lined up before him, their postures rigid yet energetic.
These were no ordinary disciples; they were 'Chosen Material' extracted from the four pillars of power now under his control: five Evernight core disciples, five formidable warriors from the Tiger Guild, five shadow hunters from the Crow Guild, and five steel-muscled miners from the Stone Guild.
"Listen!" Choin's voice cut through the silence of the field, cold and sharp like a chisel striking granite.
"You are the Structural Intervention Unit. Your job isn't just to fight as soldiers. Your job is to be the 'Sensor System' for the entire Evernight Gate building. Empress Wei has sent her killer termites, the Structural Saboteurs, to tear down every pillar we've built. Today, I will teach you how to sense 'killing intent' not from an opponent's gaze, but from the vibrations they cause in the structure."
Choin ordered them into a three-story wooden building purpose-built with a complex interlocking system of supports. Under each step and pillar, Choin had installed highly sensitive spring mechanisms and Qi cables.
"Jin-Pyo! Activate the shock load simulation!" Choin commanded.
Jin-Pyo pulled a large lever. Suddenly, the building shook rhythmically. Choin jumped into the crowd of students who were beginning to lose their balance.
"Close your eyes!" Choin shouted.
"Don't use your sight. Use the Internal Finishing breathing technique to align your heartbeats with the frequency of this building. Feel where the bolts are loose. Feel where the wood is starting to crack. Sabotage begins when someone tries to alter this frequency."
A disciple from the Tiger Guild tried to move, but Choin immediately slammed his foot into the pivot point.
"Wrong! You're applying too much lateral load to this floor. If your opponent were on the floor below, they'd know your coordinates just by the shifting dust on the ceiling."
The training lasted for hours. Choin forced them to run, fight, and survive inside a structure he'd deliberately set on the verge of collapse. Social bonds began to form under the deadly pressure: the Evernight apprentices had to hold the hands of the Stone Guild members to keep them from falling, while the Crow Guild members provided shadow protection for their comrades. They learned that the safety of one person depended on the stability of the structure they shared.
As the sun began to tilt westward, Choin stepped down from the podium and walked into the shadowy area behind the bell tower. There, Gwi-Hyuk stood still, almost invisible, as if he were part of the pillar's shadow itself.
Choin handed over a scroll of black parchment marked with the critical coordinates of the East Bridge, the South Supply Depot, and the West Mine Entrance.
"Gwi-Hyuk," Choin said in a low voice that only the silent assassin could hear.
"The Intervention Unit was our static defense. But you are the 'Independent Auditor.' I want you to conduct standby patrols at these points every three days. Do not let yourself be seen. If you find any anomalies in the structure, whether it's a cut cable or an pulled peg, don't immediately kill the perpetrator. Mark the route, find who gave the sabotage order. You are my spy in the shadows of this concrete."
Gwi-Hyuk accepted the scroll, gave a curt, steady nod, and then disappeared into the darkness of the corridor without making the slightest scrape on the stone floor.
That evening, inside the administration office, now filled with building models and logistics reports, Han So-Wol was massaging her temples. She was staring at the mounting operating costs.
"Young master," So-Wol called out as she saw Choin enter.
"The Namgung clan's procurement of cast iron has already consumed 70% of our gold reserves this month. If we continue building with steel, we will face a liquidity crisis before the end of the year."
Choin sat across the table, his eyes glinting with a much grander plan.
"That's why we won't rely solely on steel, So-Wol. We need a cheaper yet stronger adhesive than traditional clay."
Choin pointed to a map of the sect's northern region, the area known as White Valley. "Remind me of the limestone mines there."
So-Wol frowned. "That area is barren and devoid of energy crystals. Elder Gong's previous management considered it a 'dead wasteland.' Even the person in charge there is Old Hang... a sect veteran who was forced to retire for refusing to go along with Gong's corrupt scheme to build the warehouse."
"Tua Hang is a wasted material, So-Wol," Choin replied.
"I met him in secret the day before yesterday. He possesses extraordinary knowledge of limestone calcination. We've made a deal: I'll restore his honor as 'Chief Material Supervisor,' and he'll give me the formula for 'Hydraulic Cement.'"
Choin took a small white stone from his pocket and crushed it on the table.
"With this limestone, we can make concrete. A material that can be shaped when liquid and harden like rock in a matter of days. This will be a revolution in our construction. I want you to immediately prepare a budget for clearing the route to the North. Tua Hang is awaiting his first mobilization instructions."
Before retiring, Choin stood on the balcony of his pavilion, gazing out into the dark and silent North.
"Hahaha! Foreman, you really are insatiable, aren't you?" the voice of the real Moen Kang Yo exploded within him, his laughter containing a suppressed thirst for conflict.
"You took twenty men, assigned that mute ghost, and now you want to dig for limestone? Why don't you just slaughter Empress Wei in her palace?"
"Because killing people is easy, Boss. But making sure the buildings you leave behind don't collapse while you're gone is the real challenge," Choin muttered to himself, wiping the lime dust still clinging to his fingers.
"Sabotage from the central palace is coming soon. If my pillars aren't strong enough, all the economic progress we've built with Shiri will be wiped out overnight."
"Whatever. But make sure when those 'termites' come, you give me permission to manually demolish their necks."
"Of course, Boss. But stick to the work schedule, okay?"