[BL] Residual Resonance

Chapter 1: Inside Sector 4

The ride to Sector C was tense and quiet. Hank drove the guild’s rusted yellow utility van through the congested city streets, while Luka nervously adjusted his gear in the back. Kai sat near the window, watching the city skyline fade into the industrial perimeter.

When they finally arrived at the staging ground, the area surrounding the Red Gate was already packed with heavy machinery, military humvees, and perimeter guards. The portal stood right in the center of an open factory yard, vertical and towering like a tear in the sky, pulsing with a deep red light that cast long, unnatural shadows across the asphalt.

They waited outside for an hour and a half.

Around eleven thirty in the morning, the heavy iron barricades opened, and the elite raid teams slowly filed out of the red portal. They were covered in dark grime, monster blood, and glowing dust. Their high-grade armor showed deep scratch marks, but their faces were triumphant. They had successfully slain the main bosses and cleared the threat.

However, the raid teams did not destroy the dungeon core located deep within the gate's center. Destroying a gate core completely collapsed the dungeon and reset its internal space, which instantly respawned every monster from scratch. By leaving the core intact, the dungeon remained dormant, giving the clean-up crews a window of time to clear out valuable resources before the portal naturally closed.

As soon as the last raid member was escorted to the medical tents, the gate commander gave the signal for the cleaners to enter. Four different third-tier guilds were lined up at the perimeter. Aether Sweep Guild was assigned to enter third.

"Alright boys, helmets on and lamps checked," Hank called out, clapping his gloved hands together. "We have Sector 4. Keep your heads on a swivel and stick to the protocol."

Kai pulled his yellow hazard helmet down over his head and clicked his headlamp on. The bright white beam cut through the dim light as he followed Hank, Luka, and Mr. Park into the swirling red portal.

Crossing the threshold felt like stepping through a wall of thick gel. The temperature plummeted instantly, and the air turned heavy, smelling like copper and burnt rubber.

Inside, the dungeon floor was pitch black. The only natural light came from scattered clusters of luminous crystals embedded along the jagged rock walls, glowing with a soft, pale hue. The path sloped downhill, leading them deep underground into a massive subterranean cavern.

It took roughly ten minutes of walking through the dark tunnel before they reached the boundary of Sector 4, where the first signs of battle appeared.

The cavern floor was littered with monster corpses left behind by the vanguard guilds. Kai and his team stopped in front of a cluster of six-legged panther beasts. Their fur was coarse like wire, and their eyes were hollow sockets.

"Luka, Park, start on the hides. Kai, chip away at the wall crystals," Hank instructed, pulling out a set of heavy bone saws and butcher hooks from his equipment pack.

The butchering process was methodical and messy. Luka and Mr. Park worked as a team on the first beast. Using sharp, curved skinning knives, they made long incisions starting from the base of the monster's neck, cutting straight down the stomach to the hind legs. They pulled the tough, leathery hide back with heavy iron clamps while slicing through the connective tissue beneath, peeling the skin off in one whole sheet.

Once the hide was stripped, Hank used a hand-cranked bone saw to cut through the ribcage. The heavy blades buzzed against the dense bone, spraying dried marrow and dark blood onto their plastic aprons. Deep inside the chest cavity sat the monster’s mana core, a hard, glass-like orb glowing with faint energy. Hank reached in with rubberized tongs, pulled the core free, and dropped it into a lead-lined storage pouch.

While they processed the meat and cores, Kai stepped toward the cave walls holding a heavy iron pickaxe. He found a cluster of luminescent mana crystals growing out of the jagged stone like translucent quartz. Raising the pickaxe, he swung with steady, practiced rhythm, striking the rock right at the crystal base.

Clang. Clang.

With a dull c***k, a fist-sized blue crystal broke free and dropped onto the dusty floor. Kai did not pick it up. According to standard cleaning procedure, heavy minerals were mined first and left on the ground where they fell. The team would gather all the loose crystals into transport carts on their final sweep out of the dungeon.

As they pushed deeper into Sector 4, the environment became increasingly harsh. The red miasma hanging in the air grew noticeably thicker, drifting through the tunnels like dense swamp fog. Even with their headlamps blazing and the luminous crystals on the walls, the path ahead barely showed a few feet of visibility.

"Man... my chest feels like it's burning," Luka muttered, pausing to wipe his visor. He let out a dry cough, his hand trembling slightly against his skinning knife.

Hank leaned against his haul bag, breathing heavily. "The miasma concentration is way higher than the briefing said. Stick together, everyone. Don't take off your respirators for any reason."

Beside them, Mr. Park was rubbing his temples, visibly struggling with a mounting headache caused by the toxic air seeping through his filter filters.

Kai watched them closely. He felt perfectly fine, but he knew his co-workers were suffering from early miasma poisoning. If they stayed in this concentration for another hour, they would end up in the emergency ward.

Kai casually stepped closer to Hank and Luka under the guise of reaching for an extra collection bag. As he moved, he quietly opened his palms inside his heavy work gloves.

He activated his hidden ability, keeping it tightly controlled.

Instead of creating a wide purification pulse that would alert everyone, Kai formed a subtle, invisible suction force right around his own body. He drew the floating particles of red miasma away from Hank and Luka, pulling the toxic energy directly into his own hands and absorbing it instantly into his core. His altered body swallowed the corruption, breaking it down into harmless residual air without a trace.

He made sure not to clear the air completely. If the thick fog suddenly vanished in a five-foot radius around him, Hank would notice immediately. Instead, Kai only absorbed enough toxicity to reduce the pressure on his team's lungs, leaving just enough discomfort so it felt like normal physical exhaustion.

Within two minutes, Luka’s breathing smoothed out, and Hank stopped rubbing his chest.

"Whew," Hank breathed, shaking his head. "Must have been a bad pocket of air back there. Seems a bit lighter now."

"Yeah, thought my lungs were gonna collapse," Luka laughed weakly, picking up his gear. "Let's keep moving so we can get this bonus."

Kai offered a small, quiet nod and followed behind them, keeping his gloves closed.

They walked another fifty yards to the far end of Sector 4, where the tunnel opened up into a wide dead-end chamber.

Standing right in the center of the cavern floor was a colossal carcass.

It was a giant Centaur, easily twice the height of a normal man. Its lower body was that of a muscular, iron-scaled warhorse, while its upper human torso was massive, featuring two curved bull horns extending from its brow. The beast was covered in deep blade cuts and scorched blast marks left behind by the S-Rank raid squad that had brought it down.

The team stopped in their tracks, staring at the sheer scale of the creature in awe.

"Damn," Hank whispered, whistling softly. "A High-Rank Centaur General. The main guild must have killed this one before moving to the core room."

"How much do you think its horn core is worth?" Luka asked, his eyes wide.

"Enough to pay for our bonus three times over," Hank grinned. "Alright, don't just stand there. Let me get the heavy shears."

The team gathered around the massive beast and began the lengthy butchering process. Hank started at the head, using a heavy hydraulic saw to sever the thick bull horns right at the skull line, where the highest concentration of dense mana resided. The blade ground loudly against the bone-like horn, sending sparks flying through the dim light.

Meanwhile, Mr. Park and Luka took position near the torso. They used broad steel blades to slice through the thick skin behind the Centaur's collarbone, peeling back layers of tough muscle to reveal the chest cavity. Kai stood right beside them with a heavy iron wedge and sledgehammer, driving it into the monster's sternum until the thick bone split open with a loud c***k. Working together, Mr. Park and Luka reached deep inside to carefully slice away the connecting blood vessels and pull out the glowing, fist-sized S-grade core.

Kai kept his focus on driving the wedge deeper into the sternum, though his sharp senses, sharpened far beyond normal human limits, still picked up the faintest vibrations humming through the cavern walls.