The Undergrid seemed endless.
Twisting corridors of forgotten history stretched before them, deeper and darker than anything Naruto had imagined. Every step away from the battlefield with the Phantoms felt like plunging further into a dream that refused to wake.
Naruto's hand still tingled from holding the fragment. It pulsed faintly against his palm even as he tucked it into a secure pouch stitched inside his jacket. Kai moved ahead silently, her blade already cleaned and sheathed, every motion efficient, minimalistic. She didn't waste energy — or trust.
They came to a halt at a fork in the tunnels.
Kai raised two fingers in a silent signal.
Wait.
Naruto obeyed instinctively, pressing himself against the cracked stone wall. A sound echoed faintly ahead — not metallic, not mechanical.
Voices.
Human.
Naruto narrowed his eyes, letting the system filter the noise. Lines of ghostly blue script scrolled past his vision.
[Identifying language signature...]
[Old Shinobi Dialect – Variant 6 detected]
[Translation patch active]
Kai leaned closer. Her whisper barely stirred the air.
"Survivors. Coreless."
Naruto blinked. "Coreless?"
She nodded once, her expression tight.
"They're shinobi who lost their chakra nodes during the Cataclysm. Their systems were damaged… severed. They can't use jutsu anymore. Some say they're cursed. Others say they adapted."
"How?" Naruto asked quietly.
Kai's mouth twisted into something between a smirk and a grimace.
"They rebuilt themselves. Spliced their bodies with old tech. Scroll matrices, forbidden seals, experimental constructs. They're ghosts clinging to whatever scraps of power they can steal."
Naruto's stomach twisted. He couldn't imagine losing his chakra. Losing that sense of being alive. Of feeling the energy of the world in every heartbeat.
"What do they want?"
Kai's eyes darkened.
"Same thing we do. A way to end the Throne's reign."
A loud clatter interrupted them — a crash of metal striking stone. The voices ahead raised into shouts. Naruto tensed, ready to move.
Kai was already sprinting forward.
He followed without hesitation.
The corridor widened into an abandoned marketplace — or what had once been one. Rusted vendor stalls, collapsed canopy frames, and broken neon signs littered the area. In the center, a skirmish was unfolding.
Five Coreless, each outfitted in mismatched armor — a fusion of old-world flak jackets and new-world mechanical grafts — were fighting a Phantom unit. Not Executors like before. These were Hunters — faster, sleeker, built for pursuit and assassination.
The Coreless were losing.
Badly.
One woman with a mechanical arm fired a volley of kunai from a wrist launcher, but the Phantom dodged effortlessly, closing the distance and slashing with a razor-edged whip that carved a Coreless man nearly in half.
Naruto felt the system surge.
[Request: Engage combat protocol?]
[Y/N]
He didn't even think.
Yes.
He dashed forward, system lines blazing faintly around his fists. The Coreless noticed him — some flinched, expecting betrayal — but he ignored them.
His target was clear.
The Phantom Hunter turned, sensing him.
Too late.
Naruto leapt, feinting high, and then dropped low at the last second, sweeping the Phantom's legs out from under it. Before it could recover, he slammed his palm onto its chestplate and activated the system's mimic function.
[Skill trigger: Hijack Pulse Lv. 1]
[Effect: Temporarily disable Hunter-class kinetic systems for 4.3 seconds]
The Phantom spasmed violently.
Kai was a blur behind him, her blade flashing.
In one swift motion, she severed the Phantom's main support link, the thin connection between its core processor and its external shell. The body collapsed instantly, lifeless.
Silence fell.
Naruto straightened slowly, breathing hard.
The Coreless circled them warily, weapons raised.
One of them, a tall man with a jagged scar running across his jaw and a mechanical eye that clicked softly as it focused, stepped forward.
"You're not Throne-bound," he said. His voice was raspy, damaged.
"No," Kai said flatly. "We're hunting the same enemy."
The man studied her for a long moment, then turned his gaze to Naruto.
"You've got old chakra in you," he said. "Fresh. Unbroken."
Naruto bristled slightly. Was that resentment in his tone?
Kai stepped between them subtly.
"We need safe passage. We have fragments."
The Coreless man's eye widened slightly at the word. Around him, his companions murmured.
Fragments were currency down here. Power. Hope.
"Follow me," the man said after a moment's hesitation. "The Elders will want to see you."
Naruto exchanged a glance with Kai. She nodded almost imperceptibly.
They followed.
The Coreless led them through a series of hidden paths — through cracked stonework, down forgotten maintenance shafts, and across rusted bridges suspended over endless black pits. It felt less like traveling through a city and more like navigating the carcass of some dead god.
Finally, they arrived.
The Coreless enclave was hidden inside the wreckage of an ancient shinobi fortress — a place Naruto vaguely recognized from old Academy textbooks. Fortress Tengen. A relic from the Warring Clans era, long before the first villages united.
The Coreless had rebuilt it with whatever they could scavenge — a patchwork of tents, scaffolds, and jury-rigged chakra suppressors. Children with cybernetic limbs darted between stalls. Elders with mechanical implants huddled around low fires, murmuring prayers in forgotten tongues.
Naruto's heart twisted painfully.
This wasn't survival.
It was desperation.
They were ushered into a large tent at the center of the camp.
Inside, three Elders sat in a circle. Each wore the remnants of old Kage cloaks, torn and faded, their symbols barely visible. Their bodies were more machine than flesh — wires feeding into their spines, metallic plates replacing arms and legs.
The lead Elder, a woman with silver hair and a voice like grinding gravel, spoke first.
"You bring fragments."
It wasn't a question.
Kai nodded, producing the two fragments they had secured. Naruto added his own. The fragments pulsed in unison, resonating faintly with something deep below the earth.
The Elder's eyes gleamed.
"With enough of these, the Heartline can be reactivated," she said. "The Throne's roots severed."
Naruto frowned. "Heartline?"
The Elder smiled thinly.
"The Heartline is the old world's lifeblood. The original chakra network. Before the Throne corrupted it, before the Cataclysm rewrote the laws. If we restore it… we restore choice. Freedom."
Kai crossed her arms.
"How many fragments remain?"
The Elder's smile faded.
"Too many. Scattered across forbidden zones. Guarded by the Throne's deepest servants."
Another Elder, his voice weak and whispery, added, "But we have located a vault. A depository of lost fragments. Enough to tilt the balance."
Naruto straightened.
"A mission?"
The lead Elder nodded.
"We cannot leave this place without risking annihilation. But you…" Her gaze settled heavily on Naruto. "You are unbroken. Your system is free. You can reach the vault."
Kai was already studying a map the Elder unrolled across the ground.
It marked a place deep within the Broken Spiral — a ruin so dangerous it was said to be a graveyard for the greatest shinobi who ever lived.
Naruto looked at Kai.
She looked back.
Silent agreement.
They would go.
They had to.
The Heartline had to be restored — or the Throne would never fall.
The lead Elder spoke one final time, her voice dropping into something almost like reverence.
"You are Recode."
Naruto blinked. "What?"
The Elder smiled.
"The world broke. But you… you are its chance to rewrite itself."
Naruto felt the weight of that truth settle on his shoulders.
Not just a survivor.
Not just a fighter.
A Recode.
A glitch in the destiny the Throne had forced upon them all.
He clenched his fists, feeling the system hum inside him.
They would reach the vault.
They would gather the fragments.
They would break the cycle.
One way or another.
Even if it meant burning the world down first.