The empty lime bins smelled of dry, dead dust.
Lin Ke stood in the storage annex of the Seventh Ward. He stared into the yawning hollow of the flux warehouse. The stone floor was swept clean. Not a single lump of burning lime powder remained. Not a basket of crushed river quartz.
Outside, the heavy rain hammered against the clay roof tiles, dripping through cracks into wooden collection buckets with an irritating, irregular rhythm.
“Every cart,” Meng Shan rumbled from the arched doorway, his massive frame blocking the grey daylight. “The Grand Fortune factors cleared the entire southern quarry road before sunrise. Bought the lime at triple market price. Even bought the river dredgers’ quartz gravel.”
Meng Shan stepped inside, shaking sheets of water from his oiled canvas cloak. His broad face was tight with restrained fury.
“Elder Wu was shouting in the office hall,” Meng Shan added. He leaned against an empty timber bin. “Said Zhao Wuji personally signed the supply order through the Outer Court Logistics Board. It’s marked as an ‘Essential Construction Reserve’ for the Inner Sect’s new training pavilions.”
“A classic supply-chain stranglehold,” Lin Ke said, without turning around. He stepped down into the dry pit. He bent to pinch a speck of white powder between his index finger and thumb. “Deny the flux, and the fire can’t separate quartz dust from the iron melt. The quartz dust remains suspended in the molten puddle, forming high-thickness silicates that turn the iron into brittle, unforgeable honeycombed melted rock waste.”
“Can we melt without it?” Meng Shan asked.
“No,” Lin Ke said flatly. “Without a basic flux to bind the acidic silicon dioxide, the melting point of the melted rock waste stays at seventeen hundred degrees. Our coal can only push eleven hundred. The iron will trap the stone inside itself. When struck, the blooms will shatter like dried mud.”
He dusted his fingers against his hemp trousers.
The dull ache in his left radius was muffled by the thick layer of Apothecary He’s grey bone-setting paste, bound tightly beneath strips of boiled linen. But the living clock was ticking. He had three months before the hardened melted rock waste in his marrow triggered systemic failure.
To buy the high-grade chelation reagents he needed to survive, he couldn’t just scrape by on sect rations. He needed capital. Hundreds of spirit stones.
And capital needed high-purity iron.
“Wait here,” Lin Ke said.
He closed his eyes, centering his breathing in the dark bin.
Tianfu. Branch.
In the mental sandbox, Lin Ke opened the local deep-rock database of the Iron Sword Province.
Zhao Wuji had cornered the market on white lime-chalk (limestone) and pure quartz dust sand (river quartz). Traditional metallurgists in this world viewed those two minerals as the only divine gifts capable of “cleansing the earth-metal spirit.”
Dogmatic superstition, Lin Ke analyzed. Basic fluxing isn’t a spiritual rite. It’s an acid-base neutralization reaction at eleven hundred degrees.
He tested common substitutes in the mental fire.
First trial: raw fire soot mixed with clay.
In the test model, the clay melted. But the high light metal content formed heat-proof mullite crystals. The melted rock waste foamed wildly, choking the fire chimney pipes with expanding froth and splashing molten droplets across the room.
Second trial: river mud and wood ashes.
The potassium carbonate in the wood ash lowered the melting point. But the volatile organics boiled away too rapidly, causing violent micro-explosions within the melted rock waste layer. The heat shock fractured the crucible wall.
Think like a materials engineer, not a potion-maker, Lin Ke commanded his thoughts. What is nearby? What is free? What is discarded in mountainous piles because no one knows what to do with it?
His thoughts flashed to the quarry discard pits where Meng Shan’s clan had labored for ages.
The tailings piles. Mountainous hills of pinkish-grey stone rejected by the stonecutters. That was because it was too brittle for foundation blocks.
Pink rock-rich granite gravel.
Potassium and sodium aluminosilicates. On its own, granite was acidic. But when blended with calcined bone ash—calcium phosphate—the combination formed a low-melting eutectic mixture. The bitter salt metal ions (potassium and sodium) would act as powerful network breakers in the molten stone-glass chains. It dropped the liquidus heat of the melted rock waste by over two hundred degrees.
He ran the phase diagram in the sandbox.
Ratio: three parts crushed pink rock gravel, two parts calcined animal bone ash, half a part crushed magnetic iron waste scum.
The mental crucible ignited. The mixture hit eleven hundred degrees.
The reaction unfolded with total crystal-clear perfection. The acidic quartz dust dissolved into the bitter salt-phosphate liquid with zero foaming. The resulting melted rock waste possessed the fluid thickness of warm oil, floating effortlessly atop the dense, purifying puddle of liquid iron.
Lin Ke cut the mental branch.
He slipped his hand into his robe, pressing the iron metal pen into his thumb.
“Branch checked: main,” he whispered.
He opened his eyes and stepped out of the dry lime bin.
“Meng Shan.”
“Aye?”
“Your clan’s quarry pits. The northern tailings pile. The pinkish-grey stone that fractures into flat plates when struck—the stone the masons throw away.”
Meng Shan blinked, scratching his bearded chin. “The pink gravel? That’s rotten stone. It’s too brittle for paving flags, and it crumbles under water erosion. We’ve piled three hundred cartloads of it behind the crushing yard. It’s fully worthless.”
“Bring two cartloads,” Lin Ke said. “Now.”
Meng Shan looked at him, then grinned—a wide, ferocious baring of teeth. “The carts are already hitched behind the shed. I’ll have them here in twenty minutes.”
While Meng Shan was gone, Lin Ke stoked the lower draft of Crucible Four.
He didn’t use the fire apprentices this time. He couldn’t afford leaks. The boy who had coughed black bile was recovering in the bunkhouse. The other hands were locked in the office hall listening to Elder Wu’s wild lecture on quota responsibilities.
Meng Shan hauled the two dripping wooden handcarts into the yard. Then, Lin Ke already had the heavy stone edge-runner mill prepared.
They dumped the pink granite rubble under the crushing wheels.
Meng Shan threw his thick shoulders against the timber drive arm, his Distributed Earth-Core Stance locking his boots to the flat stone slabs. With each massive heave, the stone wheel rolled over the granite, grinding the pink rock into a fine, gritty powder that looked like crushed rose quartz.
Lin Ke hauled sacks of calcined bone ash from the kitchen refuse piles, dumping them into the mixing trough. He added three buckets of water to suppress the dust, working the mixture with an iron spade until it formed a damp, grey-pink slurry.
“That’s it?” Meng Shan panted, wiping sweat from his brow with a greasy forearm. “Refuse and gravel?”
“Heat laws doesn’t care about market prestige,” Lin Ke said, checking the fire heat through the quartz peep-hole. “Charge the top hopper. Twenty pounds of flux slurry for every hundred pounds of raw ore.”
They loaded Crucible Four.
For the next four hours, the Seventh Ward hummed with an unfamiliar, steady shaking.
Under Lin Ke’s precise draft calibrations, the fire didn’t choke. It didn’t vomit toxic plumes. The pink rock slurry reacted with the bone ash in the heart of the firebox. It dissolved the acidic stone ore into a silky, emerald-tinted liquid that ran like water down the melted rock waste runner.
At the bottom of the crucible, the iron atoms settled by thickness, aligning into tight, crystal-clear grains free of sulfur and quartz dust inclusions.
When Lin Ke drove the tapping rod through the clay seal, the liquid metal didn’t spray or hiss.
It poured in a nonstop, heavy, mirror-bright stream.
As it filled the sand channels. It cooled in the damp air, the surface didn’t form the rough, pockmarked crust of ordinary fire blooms. Instead, delicate, frosty dendrites formed across the grey metal. Fine, shimmering feather patterns that reflected the lantern light like frost on winter glass.
Meng Shan dropped his tongs, his eyes bulging.
“Cold-Patterned Iron,” Meng Shan whispered in awe. “Grade-2 refined... Brother Lin, that’s not fire bloom. That’s weapon-grade metal bar! Only the First Ward’s blast masters produce this. They burn five stones of spirit coal per batch!”
“Grade-2 Cold-Patterned Iron,” Lin Ke confirmed. He measured a metal bar with his brass measuring tongs once it chilled below four hundred degrees. “Hardness forty-two on the sect scale. Sulfur content under zero-point-five percent. Perfect crystal-clear grain structure.”
He grabbed a heavy hammer and struck the edge of a metal bar with full force.
Ting!
A clear, bell-like ring sang through the empty ward. The metal bar didn’t chip. It didn’t dent. The blast wave shook through the floor, clean and sharp.
“How much did we pour?” Meng Shan asked, his voice shaking with excitement.
Lin Ke walked along the cooling beds, his ledger brush flashing across the dry parchment.
“Two hundred and ten pounds,” Lin Ke calculated. “Sixty pounds to satisfy Elder Wu’s monthly quota and keep his pension intact. That leaves an unallocated surplus of one hundred and fifty pounds.”
Meng Shan swallowed hard. “One hundred and fifty pounds of Grade-2 Cold-Patterned Iron... On the open market in Cloud Mist Market, weapon smiths pay four spirit stones for every ten pounds. That’s... Sixty spirit stones.”
Sixty spirit stones.
Enough to buy half of the Marrow-Nourishing Jade Broth he needed to save his skeleton. Enough to buy high-purity red stone flux, refined spirit iron powders, and the medical tools necessary to begin stabilizing his failing foundation.
“There’s only one problem,” Meng Shan rumbled, his excitement suddenly dimming. He nodded toward the outer iron gate. “Zhao Wuji’s cousin, Zhao Ba. He posted three armed debt-inspectors at the North Gate this morning. They’re checking every cart leaving the smelting district. If they catch us with unbonded Grade-2 metal, they’ll seize the iron, declare us thieves, and drag us to the Punishment Hall.”
Lin Ke looked down at his banded left forearm. The ache was deep, but his mind was crystal clear.
“Then we don’t carry iron,” Lin Ke said, his voice flat and steady. “We carry garbage.”