The scent of blood clung to the air like smoke.
Each step deeper into the tunnel felt like treading water in a sea of ghosts. The fluorescent lights overhead flickered inconsistently—some strobing violently, others completely dead. The ones that worked only served to paint everything in a ghastly, yellow tint.
Kai walked at the front, eyes narrowing with each new corner. His senses were sharper now—too sharp. He could hear the heartbeat of those behind him, could smell the sweat clinging to Aarav's back, could hear the way Tara's breath came in shallow gasps as she lay across Riko's back now, too unstable for the stretcher.
She hadn't spoken again.
But her fingers twitched.
Behind them, Renji muttered under his breath as he wiped gore from his blade. His eyes hadn't lost that glaze since the last fight. Lina had gone quiet too, scanning each side tunnel with quick, calculated glances.
They were all changing.
Not just physically.
Mentally. Emotionally. Spiritually.
The system wasn't just tracking their stats anymore. It was watching their decisions. Their kills. Their cracks.
Kai glanced at his interface.
[Level 4]
[EXP: 240/300]
[Next Trait Unlock — 25 Kills: 22/25]
Three more kills.
That number made him feel something he didn't like.
Not fear.
Hunger.
They reached an old maintenance section of the tunnel. An entire corridor had collapsed behind them, cutting off retreat. The sound of the shifting earth still echoed faintly, like the world had exhaled and sealed their fate.
Kai held up his hand, motioning them to stop.
Up ahead, a faint sound.
Scratching.
Clicking.
Wet.
Kai crouched. His eyes adjusted quickly in the dark now—another silent adaptation the system hadn't even notified him about.
He saw it before it moved.
A malformed creature—head elongated, arms too long, crawling sideways like an insect along the walls. Its mouth split across the middle like a jagged smile.
It wasn't a zombie.
It was something worse.
Mutated by something older. Something hungrier.
It sniffed the air. Then stopped. Its gaze turned.
Right at Kai.
Kai didn't shout.
He surged forward instead.
Steel hissed.
The thing shrieked and leapt.
Kai twisted, driving his blade upward into its chest. The creature's limbs flailed, claws raking his jacket. Its blood sprayed—thick, black, acidic.
It burned through fabric, searing skin.
He didn't stop.
He yanked the blade out and cut through the creature's throat, separating its head with one clean, practiced motion.
[+60 EXP]
[Kill Count: 23/25]
Behind him, two more creatures lunged from the shadows.
Riko screamed, ducking under a swipe. Her machete came up instinctively, slicing into the mutant's belly.
Aarav fired point-blank—his shotgun roared. The blast flung one mutant against the tunnel wall in a rain of meat.
Renji leapt over the dying body, driving his knife into the base of the last creature's skull.
[+60 EXP]
[+60 EXP]
[Kill Count: 25/25]
[Trait Unlocked: Adaptive Evolution]
"You have killed enough advanced mutants. Your body adjusts to hostile environments 15% faster. Mild regeneration initiated."
Kai panted.
He felt... different.
His wounds no longer throbbed as they should have. The cuts on his side itched instead of stung. His muscles didn't shake.
He stood straighter.
The others were staring.
Not with fear.
With something approaching awe.
"Kai..." Lina whispered. "You're bleeding... and it's stopping on its own."
He looked down. She was right. The gash on his arm was already clotting unnaturally fast.
"I don't know how," he admitted. "But I think... I'm changing."
He didn't say what he was really thinking.
I need to change. Or I'll die.
They continued forward, stepping over the twitching remains of the mutants. The air felt thicker here—moist, metallic. A deep hum vibrated through the walls.
It wasn't mechanical.
It was alive.
Tara groaned on Riko's back. Her eyes fluttered open again, silver flickering in her pupils.
"They're not from here," she mumbled. "The walls… the walls remember. The blood wakes them."
Kai froze.
"Who wakes?"
But she was already unconscious again.
Renji exhaled sharply. "I'm starting to think she knows more than all of us."
"She's connected to it," Lina murmured. "Maybe it's not just infection. Maybe something's using her."
Kai clenched his fists. "We keep moving. We get to the surface. Then we decide what the hell is going on."
As they moved forward, the tunnel widened.
And they found it.
A massive nest—woven from bones, wires, clothing, and skin. Hanging from the ceiling were dozens of bodies, hollowed out and fused together into a grotesque tapestry.
At the center sat something enormous.
A Broodmother.
Eight limbs. Flesh layered like armor. No eyes. Just a mouth that opened across its entire torso.
It turned toward them.
And screamed.
[Boss Monster Detected: Subterranean Broodmother Lv. 8]
[Initiating Combat Event]
Kai stepped forward.
His hand gripped the hilt tighter. His breath calmed.
Behind him, Riko handed Tara to Lina. Aarav reloaded. Renji took position.
They didn't wait for orders.
They were ready.
Kai spoke one word.
"Kill."
And the tunnel exploded into chaos.