Pale emergency lights coldly illuminate the decayed corridor, the acrid stench of corroded steel stinging the nostrils.

  The M-sector, nestled in the ruins’ mid-layers, is shrouded in dim darkness. Creaking, rusted gears and the guttural cries of xenobeasts and lab creatures whisper from every corner. Silent but undeniable threats stalk ruin diggers, devouring them from shadows, sometimes tearing them apart, splattering blood and flesh against walls.

  Are the living, who walk the dark craving the ruins’ relics, slaughtered by past ghosts or remnants of sin and desire? Beyond the shallow-layer elevator lies the edge of a hell rife with death. Silence breeds terror, alien creatures heedless of life’s value run rampant, and the hum of killing machines frays the mind—a crucible of madness. Even veteran diggers shun this sector, where survival is a gamble. This is M-sector.

  Stepping from the elevator, Danang glances at a severed arm on the floor, then at Eve, raising his rifle to scan the corridor’s flickering lights.

  A bizarre roar—shimmering like heatwaves, blending metal rasps and beastly cries. A black xenobeast, a shadow wolf, devours an armored man’s torso, grinding organs with sharp fangs. Its mate slams the man’s head against the wall, lapping up splattered brains and blood.

  “…Eve,” Danang says.

  Before he signals, Eve’s silver wings pierce the shadow wolf’s body, cleaving it in two. The surviving mate gleefully devours its partner, lost in cannibalism.

  “Danang,” Eve says.

  He knows. Decapitating the distracted wolf with Heres, Danang faces its still-moving limbs. Eve’s wings slice off its claws, and he drives his blade into its exposed torso, shredding its pulsing heart at a molecular level.

  No need for words. Finish the job quickly and return to the undercity. Shaking black, tar-like blood from Heres, Danang closes his eyes, activates Lumina, and summons his combat AI, Nephtys.

  “Danang, your orders,” Nephtys says.

  “Visual assistance and toxin breakdown,” he replies.

  “Understood. Enemy detection needed?”

  “Yes.”

  “Commencing data sharing with Administrator Eve. Copying Eve’s Lumina construct… complete. Danang, multiple hostile signatures detected in the residential zone. Twenty-five humans. Display path to quarters?”

  Funny AI. Calling the ruins’ structure a “residential zone” and their destination “quarters”? Snorting at Nephtys’s quip, Danang requests minimal data, opening his eyes to a corridor now clear as if through night-vision goggles.

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  Two mangled corpses, three desiccated mummies, countless human bones… Dozens of reddish-brown handprints mark the walls, alongside bullet scars.

  “Let’s go, Danang,” Eve says.

  “…”

  “What’s wrong? I’ll leave you behind,” she teases.

  A child’s skull pierced by a bullet, a woman’s skeleton cradling a child, another stabbed through the chest by a blade like Heres. Human bones stand out more than xenobeast or lab creature remains. Many diggers died here, so it’s not odd, but Danang feels unease at the sight of bones protecting others.

  Undercity diggers don’t protect anyone. Rare exceptions exist, but seeing so many skeletons shielding others feels wrong, nauseating, bitter.

  “…”

  A scream pierces his ear. Gunfire and wails echo, and Danang instinctively raises his rifle, stepping back.

  “Danang?” Eve’s prismatic eyes study him curiously, following his gaze.

  Their vision holds only the dimly lit corridor, piled with death’s symbols—human and xenobeast corpses, scattered bones. No screaming diggers, no killing machines.

  “…Danang, you okay?” Eve asks.

  “…What?” he replies.

  “You look awful. Breathing hard, sweating buckets… If you’re sick, let’s head back. No need to push through,” she says.

  “…I’m fine. Let’s move,” he says.

  He’s been to the mid-layers often, knows the xenobeasts and lab creatures. But this nausea is new. Swallowing pooling saliva, clutching his throbbing head, Danang follows Nephtys’s directions.

  “Danang,” Nephtys says.

  “…”

  “Three hundred meters ahead, multiple mutant signatures, likely runaway water-molecule nanobots. Also, Necros virus-infected lifeforms detected from both side corridors. Combat prep recommended.”

  Instantly, a high-pressure jet pierces Danang’s left shoulder, linked to a transparent tube.

  “Danang?!” Eve cries.

  Blood flows through the tube into a floating sphere, rippling as it drains him, liquefying human organs into paste.

  Xenobeast—! Gritting his teeth, Danang severs the tube with Heres, scanning both corridors.

  “Eve! Right! Go right!” he shouts.

  No time to hesitate. Eve bolts right, slicing virus-infected, half-dead men and women. She blocks a jet cutter aimed at Danang with her wings.

  The compressed water jet, a white blade that cuts diamond, tears through one wing, then another. “Danang, get over here!” Eve reaches out, spotting three grenades in his hand.

  No way— Covering her ears, mouth open, Eve forms a shield with her wings, protecting against the blast and roar. Four of her five wings are active; the last plunges into the flames, pulling a severely burned Danang into the corridor.

  “Are you insane?! That was reckless!” she yells.

  Shattered armor, blown-off limbs, red muscle fibers peeking from charred skin. White worms cover Danang, repairing fatal wounds, restoring armor and limbs.

  Rising slowly, covering his aching head and dizzy vision, Danang averts his eyes from Eve’s anger. “Nephtys, report Lumina’s status, bio-metal duration, and Code Onimus time limit.”

  “Lumina, 75% usage. Bio-metal, five minutes. Code Onimus, one minute. Restricting toxin breakdown, visual aid, or detection can extend activation,” Nephtys replies.

  “No, keep them. I need all options… Eve,” Danang says.

  “What?! I didn’t give you Lumina to throw your life away!” she snaps.

  “You made it possible,” he says.

  “Huh?!” she exclaims.

  Testing his mechanical fingers, confirming his wounds are healed, Danang grips his scorched rifle.

  “I don’t take stupid risks without a chance. You were here, I knew you’d save me, so I could push it. Alone, I wouldn’t fight that xenobeast,” he says.

  “So you trusted me? …Still, don’t be reckless. If Lumina fails or you get too used to this, you’ll die easily. Don’t forget that,” Eve warns.

  “Got it.” As he speaks, he aims at Eve, firing. The bullet blows off the head of a Regenerator—a zombie granted false life by Necros—creeping behind her.

  “…Nice shot. Your arm’s okay?” Eve says.

  “…Yeah,” he replies.

  Repelling the xenobeast and facing a zombie horde, they advance, guns and blades gleaming.