The Villain Who Seeks Joy-Chapter 120: The Cavitation Pulse

The Deep-Vein Station felt less like a work of engineering and more like the interior of a dying god. We descended a spiral staircase of damp limestone that seemed to wind forever into the roots of the city. The air grew heavier with every step, saturated with a fine, misty spray that tasted of iron and ancient minerals. Above us, the rhythmic thump-thump of the primary pumps vibrated through the walls, a sound that felt like a failing heartbeat.

Master Valerius and his entourage of Hydro-Mages followed us at a distance, their teal robes hiked up to avoid the puddles. They whispered among themselves, their silver staffs casting a cold, artificial light that did little to cut through the gloom. They didn’t look like engineers; they looked like mourners at a funeral they had caused.

"The pressure in the tertiary chamber is exceeding seven hundred psi," Valerius called out, his voice echoing off the wet stone. "My mages have already placed containment wards on the outer casing. If you open that inspection hatch, the backpressure will strip the flesh from your bones."

"Your wards are the reason the pressure is building," I said without looking back. I reached the bottom of the stairs and stepped onto a grated metal walkway that suspended us over a dark, churning pool of mana-tainted water. "You’re trying to hold back a flood with a silk curtain. You’ve restricted the flow so much that the mana has nowhere to go, so it’s spinning in place, creating a vacuum bubble. That’s your cavitation."

I turned to the Royal Scouts who were hauling the Centurion’s armored segments. "Set the chassis here. Mira, I need the high-tensile silver leads. We’re not just opening a hatch; we’re installing a bypass."

Mira moved with a silent, frantic efficiency, her boots clattering on the metal grate. She began to lay out the silver wires, threading them through the reinforced conduits we had prepared at Valmere. Gareth and Cael started the reassembly of the Vanguard. In the dim, flickering light, the construct looked terrifying. The new crustacean-style plating—overlapping scales of dark iron and anti-magic glass—gave it a sleek, predatory silhouette. It didn’t look like a skeletal soldier anymore; it looked like something designed to survive at the bottom of a crushing ocean.

"Heave!" Gareth grunted, sliding the primary leg-segments into the torso.

The Centurion’s eyes flared a dull, expectant red. I reached into the leash, feeling the connection snap into place. It was stronger now, bolstered by the residual energy of the mountain. The construct gave a low, mechanical growl as its new servos whirred to life. It tested its claws—wide, shovel-like pincers tipped with Chimera glass, designed to catch and consume raw mana.

"Valerius, get your men behind the secondary blast-shield," I commanded.

"I will not be ordered around in my own station by a—"

"Now!" I barked. "Unless you want to find out what a Tier 5 mana-shrapnel burst does to teal silk. The cavitation pulse is about to hit the regulator. If we don’t bleed it into the Vanguard now, this whole level is gone."

The arrogance in Valerius’s eyes finally flickered and died, replaced by a cold, sharp fear. He signaled his mages, and they scrambled behind the heavy lead-lined doors of the observation room.

I stood alone on the walkway with the Centurion. The primary intake pipe—a massive iron cylinder three feet in diameter—was vibrating so violently that the bolts were starting to spit sparks. A low, screaming whistle began to rise from the inspection hatch, the sound of high-pressure mana searching for a way out.

"Ready?" I whispered through the leash.

The Centurion stepped forward, its heavy iron feet clanking on the metal grate. It locked its pincers onto the hatch’s release valve. I could feel the heat radiating off the pipe, a dry, blistering warmth that made my skin itch.

Three... two... one...

I slammed the "Manual Release" lever.

The hatch didn’t just open; it was nearly torn off its hinges. A roar like a falling mountain filled the chamber as a geyser of iridescent, blue-white mana erupted from the pipe. It wasn’t water. It was raw, compressed energy, a swirling vortex of unstable magic that clawed at the air.

"Consume!" I roared.

The Vanguard didn’t flinch. It plunged its claws directly into the heart of the geyser. The anti-magic glass shards began to glow with a blinding intensity as they inhaled the surge. The Friction Loop, now integrated into the construct’s internal gears, began to spin at a terrifying speed. The heat-sinks on the Vanguard’s back turned a cherry-red, hissing as they met the damp air of the cellar.

The cavitation bubble—the "clog"—hit the hatch. It was a sphere of pure, concentrated vacuum, a distortion in the air that looked like a hole in reality. When it touched the Vanguard’s claws, the shockwave threw me back against the stone wall. My vision went black for a second, my ears ringing with a high-pitched whine.

I scrambled up, my lungs gasping for air. The Centurion was buried under a shroud of steam and sparking energy, its feet literally melting into the metal walkway. But it was holding. The iridescent geyser was being funneled through the construct’s body and into the silver leads we had grounded into the station’s massive iron supports.

"The pressure is dropping!" Mira shouted from the control panel. "Six hundred... five hundred... four hundred!"

The screaming whistle of the pipe faded into a low, steady throb. The water—actual, mundane water—began to flow through the auxiliary lines, its cool, rhythmic splashing a beautiful sound in the dark.

I walked to the edge of the walkway, peering through the thinning steam. The Centurion stood hunched over the hatch, its iron plating scorched and its silver-inlaid ribs glowing a deep, exhausted purple. It had absorbed the entire cavitation pulse. It had eaten the "bomb" that had been threatening the city.

I looked at the hatch. The interior of the pipe was clear, but something caught my eye in the residual mana-film coating the iron. It wasn’t a natural clog. There, etched into the inner rim of the intake valve, was a series of microscopic, geometric runes. They weren’t Southern. They weren’t even Foundation. 𝗳𝚛𝗲𝕖𝕨𝕖𝗯𝚗𝚘𝕧𝕖𝗹.𝗰𝗼𝕞

They were a Constraint Sequence—a deliberate piece of mechanical sabotage designed to cause a pressure build-up over months.

"Armand?" Cael asked, stepping onto the walkway. "Did we do it?"

"We cleared the pipe," I said, my voice cold as I stared at the etched runes. "But we didn’t fix the problem. Someone didn’t want this water to flow. They didn’t just let the pipes fail; they programmed them to explode."

I looked up at the observation room, where Valerius was staring at us in stunned silence. The "Hydro-Mages" weren’t just incompetent. They were either blind, or they were complicit.

"Boring," I whispered, the word feeling like a lie in my mouth.

I reached out and touched the Centurion’s scorched shoulder. The construct shivered, a low vibration of triumph. We had found the stress point. Now, we just had to find out who was holding the wrench.