The brass lever moved with a heavy click that sounded like the hammer of a gun. Master Mo's face distorted as the alchemical catalyst surged through his own veins, his skin bubbling and turning the color of bruised plums. The central vat groaned, the pressure gauges spinning into the red zones while the violet liquid began to hiss into the primary conduit.
Lu Yan's leap was a blur of silver embroidered silk. He reached the platform just as Master Mo's arm expanded, the sleeve of his scholar's robe shredding to reveal a limb corded with thick, grey muscle. The two men collided with a force that shook the metal walkway.
"You think you can stop the tide with a single blade, Lu Yan?" Master Mo snarled, his voice now a wet, echoing growl. He struck out with a clawed hand, the obsidian tips scraping against Lu Yan's spring saber with a shower of sparks.
Lin Xiyao did not watch the fight because she knew her role was not with the blade. She ran toward the base of the central vat where a series of copper pipes fed into the palace aqueduct. Her Heavenly Forensic System flashed with a chaotic sequence of data as it analyzed the mechanical pressure and the chemical flow.
Heavenly Forensic System: Mechanical Disruption Mode Pressure Level: 400 PSI and rising. Vulnerability: The safety release valve is located behind the third gear assembly. Action: Apply a concentrated cooling agent to the friction point to seize the gears.
"I need to freeze the gears!" Xiyao shouted over the roar of the steam. She reached into her medical chest and pulled out a flask of Cold-Moon Essence. This was a substance her father had developed to stabilize high-temperature alchemical reactions.
On the platform above, the battle was visceral. Lu Yan was fighting with the calculated precision of a Jinyiwei commander, but the mutation in Master Mo was advanced. The alchemist was no longer human; his spine had elongated and his jaw had unhinged, revealing rows of needle-sharp teeth.
"The poison is already moving, Physician!" Master Mo laughed, his blood spraying across the walkway as Lu Yan landed a shallow strike on his shoulder. "Even if you kill me, the citizens of the Forbidden City will wake up as predators."
"Not if I break the heart of your machine first," Xiyao muttered to herself. She climbed onto the vibrating base of the vat, her fingers trembling as she positioned the flask.
System Warning: High Temperature Hazard Current Surface Temperature: 180 degrees. Risk: Severe burns to the hands. Probability of Success: 62 percent.
Xiyao ignored the heat. She poured the Cold-Moon Essence directly onto the primary gear assembly. The reaction was instantaneous. A cloud of freezing white vapor erupted from the metal, and the rhythmic grinding of the machine turned into a high-pitched scream of seizing steel. The brass lever that Master Mo had pulled suddenly snapped backward, the tension in the system reversing with violent force.
Master Mo screamed as the pressure backflow caused the glass vat behind him to shatter. The violet liquid drenched him, the concentrated essence causing his mutation to accelerate beyond the capacity of his body to handle.
"No! The stability! It is lost!" Master Mo shrieked, his body beginning to dissolve into a mass of grey, necrotic tissue.
Lu Yan grabbed Xiyao and pulled her away from the base of the vat just as the pipes began to burst. He shielded her with his body, the hot steam hissing against his leather armor. The violet glow in the room began to fade as the machinery died, leaving them in a flickering, shadow-filled hall.
"Is it over?" Lu Yan asked, his breath coming in ragged gasps. His amber eyes remained focused on the spot where Master Mo had disappeared into a pile of ash and bubbling liquid.
Xiyao checked her system one last time.
Heavenly Forensic System: Environmental Report Flow Status: Terminated. Contamination Level: Trace amounts only. Warning: The Lunar Altar in the garden is still active.
"We stopped the mass release," Xiyao said, her voice shaking with exhaustion. "But the source is still above us. The Empress's garden is the heart of the resonance. If we do not destroy the altar before the Blood Moon reaches its peak, the resonance alone will trigger every carrier in the city."
Lu Yan looked up at the ceiling, his jaw set in a hard line. "Then we go back to the garden. The Empress has seen enough of the truth to know which side of this war she must choose."
They turned to leave the laboratory, but a new sound stopped them. It was a rhythmic thudding from the basalt stairs, the sound of many feet moving in unison. The Empress's personal guards were no longer waiting in the garden; they were descending into the dark, and their eyes were already beginning to glow with a faint, predatory light.