The world was fire, smoke, and the sound of men choking.
Lin Wei's world had shrunk to a few feet of hellish orange light and a crushing, invisible weight. The air in the cave was a solid thing, thick with swirling grey-black smoke that clawed at the lungs and stung the eyes.
The heat was a scorching under desert sun, radiating from the burning pitch that clung to the cave walls where the fire pot had shattered. It was an oven, and they were the meat.
"[Environmental Hazard Analysis: Airborne Particulates (Smoke) - Critical. Carbon Monoxide Levels - Rising. Ambient Temperature: 112°F. Structural Integrity: Compromised. Estimated Time to Structural Failure/Asphyxiation: 8-12 minutes.]"
The system's alerts were cold, clinical facts in a reality of pure panic. Around him, men coughed, retched, their forms barely visible ghosts in the gloom.
A young medic, barely more than a boy, was sobbing as he tried to drag a groaning soldier with a leg wound towards the rear tunnel. Ox Li's silhouette was a monstrous shadow against the barricaded entrance, heaving a rock back into place as another probing spear thrust through a gap. The sound of the Jin outside was muffled by the collapse, but it was there—shouts, the thud of axes on stone. They weren't trying to break in. They were waiting. Waiting for the smoke and heat to do the work.
"We can't… can't breathe," a voice gasped from the darkness.
"The rear tunnel!" someone else cried. "It's our only way!"
"It's a death trap!" Sly Liu's voice, sharp as a knife, cut through the din. He materialized at Lin Wei's side, his face a mask of soot and urgency.
"I scouted it, Doc. It doesn't go out. It drops. Straight down into a sinkhole, an old river channel. It's a chimney, not an exit. We go down there, we're rats in a jar."
Lin Wei's mind, trained for triage, for sorting the salvageable from the lost, was sorting possibilities with a frantic, brutal speed. Fight? They'd be slaughtered at the bottleneck. No? They'd cook. The rear tunnel? A vertical grave.
"There's more," Liu hissed, grabbing his arm. "The walls down that hole. They're crusted with yellow crystals. The whole place stinks. Like rotten eggs. Worse."
The words landed in Lin Wei's mind not as a description, but as a formula. Yellow crystals. Rotten egg stench. His modern knowledge, usually a quiet library in the back of his skull, roared to the forefront.
"[Mineral Identification: High probability - Sulfur (S). Associated odor: Hydrogen Sulfide (H₂S). Properties: Flammable. Combustion produces Sulfur Dioxide (SO₂), a toxic, suffocating gas.]"
Sulfur. In a confined space. Heated.
A plan, insane and desperate, crystallized in an instant. It wasn't a way to fight. It was a way to create a cataclysm.
"Everyone! Listen!" Lin Wei's voice tore from his raw throat, a command that cut through the coughs and moans. "We are not dying in this hole. Ox! Forget the barricade! Get every container of strong liquor, lamp oil, anything that burns! Now!"
He turned to the panicked faces he could barely see. "The tunnel is not our escape. It is our weapon. Liu! You and your fastest—get ropes. The longest we have. Zhang!" He found the scholar hunched over a wounded man. "The mud near the seepage at the back—is it clay? Can it be shaped?"
Scholar Zhang, ever the academic even in hell, nodded hastily. "Y-yes! A sticky, fine clay!"
"Start making pots. Bowls. Anything that can hold liquid. As many as you can, as fast as you can!" He pointed to the other medics. "You three! Move the wounded as far back into the tunnel mouth as you can. Wrap faces with wet cloth! Do it!"
The cave exploded into a new kind of chaos—not panic, but a frantic, directed purpose. Ox Li and two others began smashing open the remaining crates, pulling out ceramic jars of strong rice wine used for sterilization, the small, precious stores of lamp oil. Sly Liu and his scavengers produced coils of rope from their packs. Scholar Zhang and a group of medics scrambled to the damp rear wall, scooping up handfuls of dark clay, their hands moving in a feverish, primal pottery.
Lin Wei worked like a man possessed, his mind a machine. He ignored the heat, the smoke, the screaming alerts in his vision. He mixed the oil and alcohol in the crude clay pots, creating a volatile, stinking slurry. He packed them with rags as wicks. They were not weapons. They were igniters.
"The plan," he barked, his eyes meeting those of his core team—Ox Li, Sly Liu, Scholar Zhang. Their faces were smudged with soot, their eyes wide with a mixture of terror and a fierce, clinging trust. "We lower these pots down the sinkhole on ropes. We lower them to where the sulfur is. Then, we shoot a fire arrow into them."
Ox Li's brows furrowed. "An arrow? In this smoke? To light a few pots? It will be a candle, nothing more."
"No," Lin Wei said, his voice dropping to a grating whisper. "The fire will ignite the fumes from the sulfur. The heat and the gas… in a confined space like that sinkhole… it will not just burn. It will explode. It will blow fire and poison back up this tunnel, out through the entrance we collapsed. It will look… it will look like the mountain itself is vomiting hell. The Jin will run. They will think we are all dead, consumed. It is our smokescreen. Our only way out is through that river channel below."
The silence that followed was profound, broken only by the crackle of fire and a groan from a wounded man. It was madness. It was alchemy, not warfare. It was a gamble with their lives as the stake.
Sly Liu was the first to move, a feral grin cutting through the grime on his face. "A devil's trick. I like it."
The descent into the sinkhole was a journey into the belly of the earth. The air grew cooler, damper, but the stench of rotten eggs intensified, a metallic, suffocating smell that promised death. The river channel at the bottom was a shallow, icy trickle over smooth stone.
Above them, the shaft they'd climbed down was a distant circle of murky, smoke-veiled light.
Working in near-total darkness, guided by a single shielded lantern, they prepared the trap. The crude clay pots, filled with their volatile cocktail, were lowered on ropes, dangling just above the section of wall crusted with thick, canary-yellow crystals. The sulfur deposits gleamed dully in the lantern light, sinister and promising.
The wounded and the rest of the men were herded downstream, around a bend in the underground channel, as far as the rope lines would allow. Lin Wei, Ox Li, and Liu remained at the base of the shaft. Ox Li, the strongest, held the army's last composite bow, a fire arrow nocked and ready. The arrow's head was wrapped in oil-soaked rags, now smoldering from the lantern's flame.
"Ready?" Lin Wei's voice echoed strangely in the cavern.
Ox Li grunted, his massive form a statue of tension. Liu gave a sharp nod, his eyes glued to the dangling pots.
"Now."
Ox Li drew, the bow creaking. He aimed not for the pots directly, but for the cavern wall just above them, where the sulfur crust was thickest. He loosed.
The arrow flew up the shaft, a tiny comet in the dark. For a heart-stopping second, nothing happened. Then a WHUMP as the oil-soaked rags ignited, splashing fire against the wall.
A heartbeat of silence.
Then the world turned inside out.
It wasn't a sound so much as a pressure, a fist of hot air that punched down the shaft and knocked them off their feet. A deep, subterranean roar swallowed all other sound, followed by a blinding, actinic flash of sickly yellow-white light that shot up the chimney-hole.
A torrent of fire, like the breath of a dragon, vomited upwards, followed by a billowing plume of choking, yellow-gray smoke that stank of brimstone and death.
The cave around them shuddered. Rocks clattered down from the ceiling. The heat was instant and blistering.
"GO! GO! GO!" Lin Wei screamed, the words soundless in the ringing aftermath. They scrambled, slipping on the wet stone, fleeing down the underground river as behind them the mountain continued to groan and bellow, a fake volcano of their own making.
Hours later, under a cloak of blessed, cool rain that had begun to fall, a ragged column of survivors emerged from a fissure in a riverbank two miles downstream. They were ghosts—covered in slime, soot, and sulfurous residue, their eyes wild with the aftermath of terror. But they were alive. They had saved seventeen of the twenty-two wounded. They had saved themselves.
The story that reached the main camp ahead of them was not one of a desperate, scientific gambit. It was a legend born of fear and the supernatural.
A scout, white-faced, reported to Commander Xin: "Sir… the Jin… they broke. They ran. The mountain… it spoke. Fire and a poison fog came from the cave mouth. They say… they say the Surgeon-General summoned the wrath of the earth. That he made a pact with the mountain spirits to consume his enemies."
By the time Lin Wei and his bedraggled band stumbled into the outskirts of the camp, the tale had grown wings. He was no longer just a doctor; he was a sorcerer who had harnessed hellfire.
The summons to Yue Fei's tent came before Lin Wei could even wash the stink of sulfur from his skin. The atmosphere inside was thick with a different kind of tension.
Yue Fei sat behind his campaign table, his face unreadable. Flanking him was the cold, pinched face of Commissioner Deng, and a stern, senior staff officer from the headquarters, a man with eyes like chips of flint.
Commissioner Deng spoke first, his voice dripping with pious horror. "You see, Commander? You see what his… innovations lead to? Pact-making with dark forces? Unnatural explosions? The men are calling it sorcery! This is not medicine; it is heresy! It destabilizes the men's faith, it invites calamity!" He pointed a bony finger at Lin Wei. "This 'Surgeon-General' traffics in elements that offend heaven and earth!"
Lin Wei stood, exhausted, filth-caked, but his spine was straight. He did not look at Deng. He looked at the staff officer, then at Yue Fei. He reached into a pouch at his belt and pulled out a chunk of the yellow crystalline rock. He placed it on the table with a soft click.
"Sulfur," he said, his voice hoarse but clear. "A mineral. Found in caves near hot springs and volcanic vents. When heated, it produces fumes. Fumes that are flammable." He spoke as if giving a lecture. "The Jin trapped us in a cave with a sulfur deposit. They tried to burn us out. We used the materials at hand—strong alcohol, oil, and the mineral already present—to create a smokescreen and a diversion. The fire ignited the sulfur fumes. The resulting combustion and gas forced the Jin to retreat and provided cover for our escape via an underground river channel."
He paused, letting the simple, chemical truth hang in the air, a stark contrast to Deng's superstitious ravings.
"The Jin broke the first rule of warfare: know the ground beneath your feet. They did not. My scout did." He nodded to Sly Liu, who stood silently by the tent flap. "Their ignorance of the terrain was their weakness. My knowledge of it—and of the properties of the world—was our strength. Would the Commissioner," he asked, turning his smoky, exhausted eyes on Deng for the first time, "have preferred we sat in that cave and died, to avoid the appearance of ingenuity?"
Deng spluttered. "Knowledge? This is base alchemy! Trickery!"
"It is chemistry," Lin Wei stated flatly. "The same principles that govern the black powder in our fireworks. Is the Imperial Arsenal also heretical?"
The staff officer from Yue Fei's headquarters held up a hand, silencing Deng. His flinty eyes were fixed on Lin Wei. "You captured a Jin scout."
"We treated a wounded Jin soldier found near the cave," Lin Wei corrected. "He is in our care. His leg was broken in the retreat. In return for his life, he provided information. The Jin high command has issued new orders. Their primary targets are no longer our officers. They are to target our wounded and track them to our aid stations. They are then to destroy those stations with incendiary projectiles. This is their new tactical doctrine. We have adapted by decentralizing our medical corps. They have now adapted again."
He delivered the intelligence not as a boast, but as a field report. The implication was clear: while Commissioner Deng worried about rumors, Lin Wei was fighting a war of information and counter-measures.
The tent was silent. Commissioner Deng looked furious and deflated. The staff officer's gaze was calculating. Yue Fei's mouth was a thin, hard line, but a spark of grim approval lit his eyes.
The staff officer stood. "Commissioner Deng, your concerns are noted. They are also irrelevant." His words were a slap. "Strategic adaptation to enemy tactics supersedes doctrinal adherence. Surgeon-General Lin identified a new Jin strategy, survived its implementation, captured intelligence from it, and has already formulated a counter-adaptation. This is not heresy. It is tactical acumen of the highest order."
He looked at the generalissimo, Yue Fei declared "Your analysis is confirmed by other sources." He meant spies. "Your mandate is now expanded. You are hereby promoted to Strategic Medical Advisor to the Northern Front. You will continue to develop and deploy your medical corps. But you will also now be tasked with analyzing the Jin logistical and medical capabilities. Your objective is to develop counter-strategies. If they target our healing, we must target theirs. If they rely on supply lines, we must find their vulnerabilities. You are to think not only of preserving our strength, but of eroding theirs. You are to become a weapon against their ability to wage war."
It was not praise. It was a colder, heavier burden. The healer was being ordered to learn how to break bones as well as mend them.
Commissioner Deng slunk from the tent, defeated. The political attack had not just failed; it had backfired spectacularly, proving Lin Wei's indispensable, ruthless competence.
Alone later, in the quiet of his own tent, the directive in Lin Wei's mind updated, its text cold and unambiguous in the darkness.
"[Primary Directive: Win the War.]"
"[Sub-Directive: Evolve the System.]"
"[New Mandate: Enemy Medical & Logistical Analysis. Develop Counter-Strategies.]"
"[Political Threat Status: Neutralized. Credibility: Consolidated.]"
He looked at his hands, still stained yellow with sulfur and black with soot. He had escaped the cave. He had routed his political enemy. But he had not escaped the war. It had simply changed shape, slithering inside the tent of command, and had now handed him a knife, expecting him to know where to cut. The healer was gone. In his place stood a strategist of life and death, and the line between the two had just grown terrifyingly thin.