The breathing dark ahead was thicker than air had any right to be — warm, humid, smelling faintly of rust and rotting fruit. Each inhale coated my lungs with something invisible, something that wanted to stay there.
We moved in silence. Every step into the tunnel felt wrong, as if we were walking down the throat of something that knew we were here. The walls shivered when I brushed my hand against them.
The girl walked ahead of me, her silver-grey eyes fixed forward, her movements deliberate and almost too calm. I didn't trust her calm.
"You still haven't told me your name," I said.
"You haven't asked until now."
"Fine. I'm Jin."
She paused mid-step, head tilting slightly, like the name meant something. "Lira."
It didn't feel like a lie, but it didn't feel like the whole truth either.
The tunnel widened, and a faint light pulsed ahead, slow and steady — a heartbeat you could see. I could feel it in my teeth.
[Proximity Alert: High-Value Entity Approaching][Symbiote Link Instability: 78%]
Every time the pulse came, the black veins in my arms swelled, almost painfully, as if they wanted to burst through the skin. My claws itched beneath the surface, begging to be called out.
"Do you feel that?" I asked.
She didn't answer, but I saw her hand curl into a fist.
We reached the chamber.
It was massive — not just wide, but tall, the ceiling disappearing into a black haze. In the center was… a heart. Not metaphorical. An actual, titanic heart, suspended in the air by living tendrils that rooted into the walls and floor. Each beat sent waves of distortion through the chamber, bending the light.
At its base lay a mound of corpses — not human, not entirely creature. Mutations. Failures. Each one partially digested into the slick floor.
The heart noticed us.
The tendrils shifted, like an animal adjusting its weight. The beats quickened. My own heartbeat matched its rhythm without my consent.
[WARNING: Neural Sync Rising – 81%]
Lira stepped forward. "It's calling you."
"I'm not answering."
"You already are."
She turned to face me fully now, her expression unreadable. "It's what made us. You, me, every crawler, every beast. It's the source. And if you get too close, it will finish what it started."
The heart beat again — faster this time — and a tendril the size of a tree root slammed into the ground inches from me, splattering warm fluid over my boots.
The HUD screamed.
[BOSS FIGHT INITIATED: Primordial Heart][Threat Level: Apex-Class]
Three more tendrils whipped out from the walls, their tips splitting open into hooked talons dripping with digestive acid. I summoned my exosheath and claws instantly. The armor formed over my skin with a grinding snap of bone.
The first tendril came low — I sidestepped and slashed it open, ichor spraying my face. The heart pulsed violently in response, sending a shockwave through the chamber that knocked me to one knee.
Lira wasn't helping. She just stood there, watching.
"Anytime you feel like joining in—" I started, but then she moved.
Not toward me. Toward the heart.
Her body shifted mid-stride — bone wings unfurling, limbs elongating into whip-like blades. It wasn't just a mutation. It was controlled, deliberate.
"WHAT ARE YOU—"
She struck a tendril and carved it in half with a single blow. The heart screamed — a sound so deep it rattled my organs.
"We can't kill it," she shouted over the noise. "But we can wound it!"
I didn't need to be told twice. I lunged forward, claws tearing into another tendril. My symbiote surged, flooding me with strength I didn't ask for. My muscles screamed, but the tendril snapped beneath me.
The heart thrashed now, its massive form pulling against its roots. The mound of corpses began to shift — and from it, creatures crawled free. Dregspawn. Dozens of them.
"Cover me!" Lira yelled.
I didn't argue. I met the first wave head-on, claws flashing, armor deflecting their bone spikes. The ground became slick with blood — theirs and mine. Every kill fed the thing inside me.
[Biomass Absorbed – Mutation Efficiency Rising][Symbiote Link: 83%]
I didn't like how good it felt.
Lira was climbing the tendrils now, her bone wings digging in for grip. The heart's beats turned frantic, each one releasing a blast of heat that scorched my lungs.
A crawler's claw raked across my back — I spun, severed its head, and shoved the corpse aside.
Then the tendril I'd cut earlier regenerated in seconds and slammed into me full-force. The armor cracked. My ribs followed.
I tasted blood.
The heart's voice was in my head now. Not words. Just want.
BECOME.
I roared back, more animal than man, and drove both claws into the tendril holding me down. Bone shattered. I tore myself free.
Lira reached the base of the heart and plunged both her whip-arms into its flesh. Light burst from the wounds — not white, but a sickly, shimmering gold. The heart convulsed.
The Dregspawn screamed in unison, clutching their heads.
The HUD flared red.
[WARNING: AREA COLLAPSE IMMINENT][EXIT ROUTE UNKNOWN]
"Lira!" I shouted. "We need to go!"
She didn't answer. She was locked onto the heart, her entire body trembling. Then, without warning, the tendril she stood on whipped sideways, flinging her into the air. She crashed into the far wall and didn't move.
I didn't think. I ran for her, dodging the flailing roots, tearing through any crawler that got in my way. I reached her, grabbed her under the arms, and dragged her toward the nearest tunnel.
The chamber roared behind us, the sound of a god in pain. The walls pulsed like they were going to explode.
We dove into the tunnel just as the floor split open behind us, teeth snapping shut where we'd stood.
Darkness swallowed us. Only the sound of my own ragged breathing remained.
The HUD blinked once more before fading to black.
[Objective Updated: The Heart Remembers You]
And I knew, somehow, that this wasn't over.