The hollow they'd found was little more than a half-buried maintenance station, rusted to its bones and forgotten by time. Its concrete walls were cracked and blackened with soot. Pipes hung from the ceiling like veins torn from a body, and old chemical drums were stacked in the corners like rusted tombstones. The wind howled softly through shattered vents, moaning as if the city itself mourned the dead.
Kael sat on a crate near the back wall, still breathing heavily. The taste of smoke clung to his tongue. Rei crouched near a patch of clear floor, her fingers coated in grime as she etched lines into the dust with the tip of her blade.
"You're bleeding," Kael said. Her left arm was streaked with crimson.
"I'll manage," she replied, not looking up. "This is more important. You need to understand where we are, and what's hunting us."
She drew a rough circle. "We're here. Sector Nine. Used to be a transportation hub before it collapsed during the Failsafe Riots."
Kael stared at the crude markings, then looked around the ruined station. "Failsafe Riots?"
"Back when the city still pretended to have a government. They tried to cut power to the Core Slums. Said the risk of instability was too high. People revolted. The reactors blew. Sector Nine has been buried ever since."
She marked several more zones on the floor. "These are the key territories. Most are controlled by warlords or factions. Red Marrow controls the south. They harvest Rotspawn and sell them. Spitebone runs the east — nothing but scavengers and organ pickers. West belongs to the Iron Choir. Ex-military zealots. All of them dangerous. All of them would kill you just for carrying a Core."
"And the north?"
Rei hesitated. Then she tapped the edge of the map. "Black Spine. No one controls it. A vertical district made of ruins and towers. If there's a place that still holds answers about Cores, it's there."
Kael leaned forward. "That's where we're going?"
"That's where I hope we'll find something useful. Maybe someone who can tell us why your Core is acting the way it is."
He looked down at his chest. The burn from where the Core first embedded had faded to a scar, but it still pulsed faintly beneath his skin, like a second heartbeat. It didn't feel like a gift. It felt like something alive.
Rei began wiping the map away. "You've been lucky, Kael. The Core hasn't flared out of control yet. But luck runs out. And when it does, the wrong pulse can turn you into a living bomb."
"You think that's what happened to the others? The Bound?"
She nodded. "Some lost control. Some pushed too far. That's Veinbreak. When a Core is overused, it burns through your nervous system. Melts you from the inside. It doesn't warn you. Doesn't slow down. You just feel power one moment, and the next you're a torch of screaming blood."
Kael winced. "You make it sound like using it is suicide."
"Not always. Some learn to control it. Bind it properly. They find balance. But even then, the cost is high. That's why most of us avoid using it unless we have to."
"Most of us?" he asked.
She was silent for a moment. Then she pulled back her coat sleeve, revealing a thin line of old circuitry etched into the skin of her wrist — faded now, but unmistakable.
"You were Bound."
"Yes."
"What happened?"
"I survived."
That was all she offered.
Kael glanced toward the entrance of the hollow. The city outside groaned under the weight of its own ruin. Somewhere in the distance, a deep, guttural roar echoed through the streets — too far to be a threat now, but close enough to remind them they were never safe.
"Rei," he said quietly. "Why me?"
She frowned.
"I mean… why does the Core even work with me? You said most Cores are picky. They reject people. Or burn them out. But this one — it didn't kill me. It took."
She stood and paced slowly to the far wall, pressing her palm against the cold stone.
"There are stories," she said. "Whispers passed between Core scavengers and ex-Binders. That sometimes a Core chooses not just a host… but something deeper. A Seed."
He raised a brow. "Seed?"
Rei turned. "I don't know what it means. But the word keeps coming up. In older Vault logs. In deep-core rituals. Seedbearer. Core-seeded. No one's sure if it's myth or real. But if your Core truly is unbound… it might mean you're not just a carrier."
Kael frowned. "Then what am I?"
She didn't answer.
Instead, she sat down again and began to clean her blade. The silence settled thick between them.
Finally, Kael spoke again. "That thing. The Rotspawn. You said it was young. What are the older ones like?"
Rei paused mid-wipe. Her fingers tightened around the cloth.
"They don't move like animals. They move like memories. Broken ones. Some remember how to use weapons. Some… they still think they're alive. The Rot doesn't just mutate flesh. It rewrites identity. Traps pain and rage in whatever's left."
Kael's voice was quiet. "That one we fought. It spoke."
"They do that. Words bleed out from the pain they carry. Rotspawn are the dead rewritten. Especially those who die near a Core. The energy binds to their veins. Twists them. Resurrects them."
He stared at her. "So when someone with a Core dies…"
"They become something worse. Something that never stops hating."
Kael's hands curled into fists. "That could've been me."
She looked him dead in the eyes. "It still could be."
A silence stretched between them, heavy with truth.
Then Rei stood and tossed the rag aside.
"We move at dusk. The Spine is four sectors out. And if the Veinhunter picks up our trail again, we need to be far from here."
Kael nodded. "And what happens when we reach the Spine?"
Rei strapped her blade back into place.
"Then we start digging for answers. And pray to whatever's left that we like what we find."