The dark rock flat stone slabs beneath Lin Ke’s crossed legs were freezing cold, leached of warmth by the underground draughts.
Above him, the vault of Furnace Cellar Four arched into the gloom like the ribs of an iron whale. A single animal fat lamp burned on the anvil beside him, its small flame sputtering against the drafts that whistled through the stone chimney pipes.
Arranged in neat, razor-sharp lines around him lay his testing suite:
Ten pounds of crushed spirit iron filings, sieved to four hundred mesh. Three bowls of scarlet red stone flux. Five clay pot vials of cold spring water. Apothecary He’s bone-setting salve. And the ancient rib scroll, unrolled flat upon a greased leather mat.
Lin Ke placed both palms flat against his knees.
In meatspace, there were no undos. There were no rollbacks.
If he started the Deep-sea Bone-Melting Chant in his physical flesh. Then he made a single rounding error in the reaction kinetics, his thigh bone would liquefy in his leg. He would die choking on his own dissolved bone marrow on the floor of an abandoned cellar.
Every failure mode must be observed in the sandbox, he told himself. Every edge case must be logged.
He closed his eyes.
Tianfu. Branch.
The mental sandbox initialized.
The physical world dissolved, replaced by the sterile, grey wireframe of his own anatomy.
In the mental space, Lin Ke activated the ancient bone chant without modifications.
The simulated marrow flared with rotting Yin fire.
Within ten breaths, the osteoclasts hyper-proliferated, swarming through the Haversian canals like starving locusts. The hardened melted rock waste dissolved—and then the outer-brain bone dissolved right behind it.
At breath forty-two, his simulated ribs collapsed under air pressure. The fifth and sixth ribs cracked inward, puncturing both lungs. The phantom Lin Ke drowned in his own blood.
Lin Ke’s real chest heaved, phantom suffocation tightening his throat. He forced his mind still and adjusted the settings.
Test model 08: Active cooling loop.
He routed the Nine-Fold Crimson cooling loop in reverse, flooding the marrow canals with cold water Qi to cool the osteolytic fire.
The result was total in reverse: the sudden heat drop induced deep crystal-forming shock. The marrow froze into brittle, glassy needles, causing instant blood-starved black rot and heart arrest at breath sixty-seven.
Test model 23: Pre-loading iron filings before dissolving.
He simulated drinking the liquid iron broth before initiating the chant, hoping the iron would act as a buffer.
The osteolytic enzymes refused to bind to the metal iron. Instead, the iron filings settled in the intestinal tract, perforating the bowel walls and causing fatal internal peritonitis.
Over the next four simulated hours, Lin Ke died sixty-four times.
He died of skull hypertension when his skull thinned too quickly. He died of systemic fat embolisms when melted marrow backed up into his lung artery. He died of total numbness when his neck bones dissolved into mush.
With each phantom death, a sledgehammer of nerve shock slammed into his lower brain.
Phantom Death Syndrome clawed at his mind like cold fingers. His real body trembled on the dark rock floor. Cold sweat soaked through his hemp clerk robes, dripping from his chin onto the flat stone slabs. His stomach heaved wildly with dry retches.
Sixty-four crashes, he thought, his mental teeth gritted against the screaming static in his nerves. Sixty-four stack traces. But the pattern is emerging.
He stopped the simulations.
He floated in the grey void, looking at the logs.
The failure mode was never the dissolving itself. The dissolving was effective—it melted the poisoned melted rock waste with terrifying smooth speed.
The failure was duty cycle.
In living systems, enzymes and chemical reactions operate in nonstop balance. But a heavy-duty refinery doesn’t run wide open until the pipes melt. An heavy-duty refinery runs on pulsed modulation.
Pulse-width modulation, Lin Ke realized, his eyes burning with cold discovery.
You don’t let the osteolytic process run continuously for hours.
You pulse it.
In the split-second active phase, the rotting Yin Qi eats just enough stone waste scum to expose the underlying connective tissue matrix without weakening the bone’s solid strength.
In the forty-split-second rest phase, the high-purity spirit iron filings—chelated by the liquid silver-sulfur bonds of the red stone—infuse into the tiny pores.
The iron atoms don’t replace the bone randomly.
They form an interstitial metal-biopolymer composite: the Ashen Iron Lattice.
Lin Ke initialized Simulation Sixty-Five.
In the test model, the grey wireframe skeleton began to pulse.
Pulse. Rest. Pulse. Rest.
Twelve split seconds of dissolving: a tiny layer of grey melted rock waste vanished.
Forty-eight split seconds of chelation. A glittering web of iron-red stone alloy knitted into the exposed calcium-connective tissue scaffold.
The test model ran past breath forty-two.
Past breath one hundred.
Past breath five hundred.
The bones didn’t collapse. They didn’t soften.
Instead, the chalky, porous grey coloration of the old Iron Marrow poison faded away, replaced by a dense, slate-grey metal sheen that looked like forged star-fallen iron.
The Haversian canals remained clear, wide, and heavy, providing clean channels for spiritual essence.
At breath one thousand, the test model reached steady state.
Lin Ke cut the branch.
Gasp.
His eyes snapped open in meatspace.
Air rushed into his real lungs with a violent, ragged whistle. His physical body slumped forward, hands planting on the icy dark rock floor to keep from collapsing face-first.
He was shivering wildly. His teeth clicked together like castanets, and his shirt was drenched in cold sweat.
His left hand shook so hard he could barely draw his iron metal pen.
He forced the blunt steel point into his thumb pad.
Hard.
The steel pierced deep into the calloused flesh, hitting the outer bone of the fingertip bone.
Blood welled in a thick, dark drop, running down his palm.
The sharp, real agony grounded his mind, cutting through the phantom memories of sixty-four deaths.
“Branch checked: main,” Lin Ke gasped, his voice cracking in the empty cellar. “Production kernel... Active.”
He leaned his forehead against the cold iron of the anvil, breathing slowly until the tremors in his limbs subsided.
The building stonework was exactly sound. The pulsed duty cycle resolved the memory leak. The chelation buffer prevented load-bearing collapse.
In test model.
Lin Ke lifted his head, looking down at his trembling hands.
A mental test model ran on idealized data. It didn’t account for the chaotic variance of real living tissue, unpredictable nearby blood pressure, or the sheer, blinding agony of having living bone remodeled while conscious.
If he tried a core commit on his entire skeleton right now, a single nearby burst could disrupt the split-second pulse timing and kill him instantly.
He couldn’t deploy to the entire public works at once.
He needed a staging environment.
He needed an isolated, single-unit physical test.
Lin Ke looked down at his left hand.
His eyes fixed on the middle finger bone of his left index finger.
One bone, Lin Ke resolved coldly. One isolated unit. If it fails, I lose a finger. If it works... I rebuild the world.