Fifty days of nonstop daily deposits brought the mortal envelope to its living ceiling.
At the fourth watch of the morning, the mountain wind howled down from the snowfields of Mount Cang. He drove icy sleet against the timber walls of the West Pavilion. Pei Jing stood motionless in the center of the dark room, his eyes closed.
He was listening to his own outer skin.
To an untrained mind, skin was merely passive wrapping. A waterproof bag designed to keep blood inside and dirt outside.
To a careful clerk who had tracked fifty days of cellular synthesis, the skin was an active, high-pressure composite material.
Every twenty-four hours, the Daily Accumulation Ledger had forced a ten percent gaining speed of epidermal rebuilding. With five silver coins of liquid capital backing the operation, the living balance sheet had remained in nonstop surplus. Forty pounds of cured pork belly fat, twenty pounds of cracked beef marrow bones, and three pots of boiled tiger-bark tonic had provided an unbroken stream of load-bearing amino acids, calcium, and unesterified fatty acids.
Pei Jing opened his eyes.
He held his hands before him in the faint amber glow of the hearth embers.
The skin across his forearms, chest, back, and shins was no longer the dull bronze of Tier 2, nor the amber hue of Tier 3. It had taken on a matte, slate-grey luster, textured with a tiny, cross-hatched polygonal pattern that looked like the cured skin armor of a southern rhinoceros.
It was neither stiff nor brittle.
When he bent his wrist, the skin folded smoothly, showing zero pushback to body articulation. But his muscles tightened. Then, the interstitial connective tissue fibrils locked together under crushing pressure, transforming the elastic sheet into an energy-scattering shield.
Under the tiny check of his tactile nerves, the five body strata of his outer skin had fully consolidated.
The basal layer was densely populated with hyper-active melanocytes and keratinocyte stem cells producing high-pulling load-bearing filaments. The spinous and granular layers had blended vast quantities of keratohyalin granules, sealing all intercellular spaces with hydrophobic natural skin oils and sterol esters. And the outermost outer skin layer was thirty times thicker than that of an ordinary mortal. He formed a seamless, flexible back shell that resisted both abrasion and chemical solvents.
He summoned the Ledger’s milestone audit:
“Tier Five Perfection,” Pei Jing murmured.
In the martial treatises of Azure Province, reaching the fifth tier of Skin Tempering was referred to as the Rhino-Leather Boundary.
It was the theoretical maximum thickness that mortal human skin could achieve before the underlying musculature had to be remodeled to support further moving loading. Fewer than one in five hundred martial practitioners in the border guard posts ever touched Tier 5. Most transitioned prematurely to basic muscle training at Tier 2 or 3. That left their epidermal envelopes weak, susceptible to deep cuts and internal hemorrhaging under weapon strikes.
Pei Jing conducted the final proof.
He walked over to the workbench. From his tool basket, he took a four-inch forged iron carpenter’s nail. A heavy, square-shanked spike used to pin roof beams into granite pillars.
The tip of the nail had been filed to a sharp, pyramid point.
Pei Jing set his left arm flat upon the split-pine table, palm upward.
He placed the point of the iron nail against the soft skin of his volar forearm, directly over the median nerve and wrist blood vessel.
He placed the palm of his right hand over the head of the nail, leaned his torso forward, and passed eighty pounds of body weight directly onto the point.
Pressure: packed downward load exceeding one hundred pounds upon a single point.
The iron point bit into the skin.
Under the microscope of his tactile senses, the outer skin layer didn’t rupture. The polygonal horn-protein scales interlocked, scattering the upright point load across the three-space-folding connective tissue mesh of his deep skin. The skin depressed by three tiny fractions of an inch. He formed a small indentation, but the deep skin held like tightly packed vulcanized leather.
Then, with eighty pounds of downward force still applied, Pei Jing dragged the nail four inches across his arm.
SCREEECH.
The sound friction was metal, harsh, and jarring, like an iron chisel being dragged across a cold granite curbstone.
Pei Jing lifted the nail.
He inspected the point of the iron spike first.
The sharp apex of the forged iron had flattened, bent slightly to the left by tiny shear pushback. The tool had suffered plastic warping.
He inspected his forearm.
Across the slate-grey skin was a faint, dusty white scrape. He wiped the skin with his thumb. The white dust vanished, revealing the smooth, unbroken rhino-leather texture beneath.
Not a single drop of blood. Not a single tiny blood vessel torn.
“solid strength: checked,” Pei Jing recorded calmly. “Skin Tempering complete.”
He tossed the blunted iron nail into the scrap bin. Then he walked over to the spruce post under the roof edge.
Over fifty days, the post had borne the brunt of over twenty thousand strikes. The dark wood was dented, splintered, and stained with sweat and crushed birch ash. Pei Jing raised his bare foot and drove a side-kick into the trunk.
THUD.
The four-inch timber post bent, groaning at the foundation. His shin felt only a solid, clean rebound of pressure, with zero bone-skin pain.
The outside hull was finished. But an armored warship with an iron hull couldn’t move through the water without an engine.
In body training, Skin Tempering was merely the outside casing. It protected the vessel from external punctures and blunt impact shock. But to generate offensive force—to cleave through iron armor, to sprint at twenty miles per hour, to shatter bone with the snap of a hip—the engine had to be built.
That engine was Flesh Forging.
Flesh Forging was the systematic reconstruction of the skeletal muscle fibers. It involved breaking down the loose, parallel muscle bundles of the human body and cross-weaving them into three-space-folding cables of dense, striated myofibrillar tissue.
A master of Flesh Forging Tier 1 could lift five hundred pounds above their head with two arms.
A master of Flesh Forging Tier 3 could tear the door off an iron wagon with bare hands.
However, building that engine carried an immediate heat-powered tax.
The floating sight screen refreshed, displaying the new body-energy projections:
Ten thousand three hundred kilocalories per day.
Nearly four hundred grams of bioavailable animal protein.
Pei Jing reviewed his balance sheet:
Liquid cash: six silver coins and four hundred copper cash. At town market prices, six silver coins bought about one hundred and fifty pounds of butcher meat and eighty pounds of soup bones—enough to sustain Flesh Forging for roughly two to three weeks.
After that, the liquid reserves would be exhausted.
Relying on butcher meat from the town stalls was an inefficient capital share-out. To sustain a daily burn of ten thousand calories and purchase the necessary bone-strengthening healing roots, he needed higher-margin assets.
He needed wild monster game from the deep crags of Mount Cang. Two-tailed horned boars, mountain bears, and iron-scaled serpents whose flesh was soaked with packed natural life-force.
And to hunt beasts of that size, the eight-inch pig-iron mountain chopper was no longer an adequate tool.
A five-inch blade lacked the reach to penetrate a five-hundred-pound boar’s chest wall or sever the main spine nerve behind a hunting beast’s skull.
He needed a true weapon.
A three-foot iron mountain saber.
He walked over to his straw pallet, knelt down, and pulled out the Black Mountain Whetstone.
The dark stone slab had accompanied him through every phase of his progression. Its eight-inch surface was slightly worn along the central trough. But the fine micro-crystal-clear texture remained as sharp and aggressive as the day he found it. He cleaned the surface with water, dried it with a clean linen cloth. Then he placed it carefully into his travel pack beside his antler-handled knife.
He checked his wrist bracers. The twelve high-carbon spring steel needles were locked in their rawhide friction channels, cold against his volar tendons, ready to release at a flick of his wrist.
He strapped on his travel sandals, adjusted his coarse wool tunic over his rhino-leather skin. Then he unlatched the heavy wooden gate.
The wind from the north blew sharp and clean. Along the mountain ridge, the first thin sliver of pale dawn light outlined the jagged peaks of Mount Cang in cold silver. Down in the valley, the early morning smelters of Cloudford Town were already coughing grey smoke into the overcast sky.
He set his boots onto the frozen mud path, his balance point low and unmoving.
“Skin is hardened,” he said, watching his breath form a steady plume of white vapor. “Now, the steel meets the bone.”