[Hidden Lab – Southern Borderlands]
The walls were pale stone—dry, cold, carved with surgical precision. Somewhere beneath the earth, Orochimaru's lair stretched like veins through a dying beast. Sasuke stood at the edge of the training chamber, watching the artificial torches flicker, shadows licking the walls like tongues.
Another corpse lay cooling against the stone.
This one had boasted a rare kekkei genkai—a mist-bloodline capable of hiding chakra signatures entirely. It hadn't helped him. Sasuke hadn't even used half his strength.
"Still too slow," he muttered, sheathing his sword.
Footsteps echoed behind him. From the archway, Kabuto entered, clipboard in hand, face as carefully neutral as ever.
"That's the fifth one this week," Kabuto observed, gaze sliding over the body. "You're making our experiments statistically unviable."
Sasuke didn't look at him. "I told you. Don't send me toys. If you want data, give me a threat."
Kabuto's lips twitched faintly—whether in amusement or something colder was impossible to tell. "Noted."
Sasuke turned away, already disinterested in the aftermath.
"Where is he?" he asked, meaning Orochimaru.
"South wing. Reviewing blood samples from what's left of the Takumi village." Kabuto adjusted his glasses. "Should I inform him you're ready for the next stage?"
Sasuke paused.
His gaze lingered on the dim corridor ahead, where the faint scent of steel, parchment, and something older clung to the air—like the breath of something molting, dying, waiting.
"What stage?" he muttered. "It's been nearly a decade, and all he's done is hand me books, riddles, philosophy quizzes. I came here to gain power, not waste years solving puzzles."
Kabuto's smile twitched wider, almost conspiratorial. "You're not the only one who's wondered."
Sasuke glanced sideways at him, a flicker of interest breaking through his usual stoicism.
Kabuto tapped the edge of his clipboard thoughtfully. "Most of the errands he sends me on, the samples he collects, even the experiments—it's all noise. No clear gain. Half the time, I think he's testing something else."
"Testing what?"
Kabuto shrugged faintly. "Us. You. Himself. I doubt even he knows anymore."
Sasuke's eyes narrowed. "I asked him once why he wastes my time."
Kabuto quirked a brow. "And?"
Sasuke's voice was low, almost bitter. "He said, 'Technique without understanding is a fruit already rotting on the branch.'"
There was a pause between them. Kabuto's smile faded into something quieter.
"Poisoned fruit indeed."
Sasuke's gaze lingered on the darkened corridor, something unspoken weighing in his chest.
"He's hiding something."
Kabuto nodded once, almost to himself. "Of course he is. That's why you're still here."
Sasuke stepped past him, voice cold as a knife's edge.
"And when I find out what it is… I'll decide whether it was worth it."
His footsteps echoed through the stone hallway, fading into the dim light.
Every step made his conviction colder, clearer.
Orochimaru thought he was shaping a weapon.
But Sasuke had stopped being anyone's blade the moment he left Konoha.
---
The corridor leading to the South Wing was colder.
Sasuke's footsteps echoed softly against the stone, the torches burning lower here—casting longer shadows. This part of the hideout always felt heavier, as if the walls themselves were listening.
He stopped outside the door without knocking.
Inside, he could hear the faint sound of parchment shifting, glass instruments clinking together like brittle bones. The sterile scent of old blood and ink filtered beneath the door.
A quiet voice greeted him before he touched the handle.
"Enter, Sasuke-kun."
He pushed the door open.
Orochimaru stood at the far end of the chamber, back turned, sleeves rolled halfway up as he inspected a series of blood samples laid out across the long stone table. Dim yellow light traced the curve of his pale neck, his silhouette serpentine and strangely still.
For a moment, Sasuke said nothing. He simply watched.
"Another one died today," Sasuke spoke first, voice even.
Orochimaru's hand paused briefly over the samples. "Another?" His voice was soft, almost amused.
"Your experiments. They can't touch me. You already know that."
Orochimaru didn't turn, only hummed—a low, thoughtful sound.
"Strength measured against the weak tells you nothing, Sasuke-kun."
Sasuke's eyes narrowed. "Then why keep sending them?"
At last, Orochimaru glanced back over his shoulder, golden eyes half-lidded, a faint smile pulling at his lips.
"To see what you do when you're offered nothing worth fighting."
The words sat like something rotten in the air.
Sasuke's jaw tightened. "Is that what this is? A lesson?"
Orochimaru's smile deepened. "Everything is a lesson."
He turned back to the table, plucking one of the blood samples and holding it up against the torchlight.
"You misunderstand me, Sasuke-kun. Power is easy to give. Easy to take. But understanding… that's far more dangerous."
Sasuke's gaze darkened. "You've wasted years teaching me riddles and questions. What does that make me?"
Orochimaru set the vial down carefully, without looking.
"A question that has not yet answered itself."
The words struck deeper than Sasuke expected.
For a long moment, neither of them spoke.
Then, quietly, Sasuke asked:
"Why?"
Orochimaru's voice was almost gentle when he replied.
"Because you are a seed. And every seed must decide whether to grow… or to rot."
Sasuke stared at him, something cold curling behind his ribs.
He turned and left without another word, the soft scuff of his footsteps swallowed by the hollow corridor.
Behind him, in the half-lit chamber, Orochimaru's faint smile remained.
---
The corridor felt colder as Sasuke walked.
The further he moved away from the South Wing, the quieter the lair became. No footsteps. No voices. Just the low, constant hum of torch flames licking stone.
Until he heard something else.
A faint, rhythmic sound—like a heartbeat echoing behind the walls.
Sasuke slowed, eyes narrowing. He glanced at the side hallway, a passage he had walked past a hundred times without interest.
Tonight, something felt different.
The pulse was subtle, almost imperceptible—a low thrum vibrating faintly beneath the soles of his feet. It seemed to bleed from one particular door at the end of the hall, one rarely used and long sealed with heavy wooden planks.
He stopped before it.
The door was unmarked, ordinary at a glance, but the air around it felt… wrong. Pressurized. Like it was breathing quietly in the dark.
Sasuke reached out, brushing his fingers lightly against the surface.
The pulse grew louder—one, two, one, two—as if the room itself had a heartbeat.
A soft voice interrupted him.
"That one's not for you."
Sasuke glanced back. Kabuto stood several steps away, expression unreadable.
"What is it?" Sasuke asked.
Kabuto adjusted his glasses, gaze flicking toward the door briefly before returning to Sasuke.
"One of Lord Orochimaru private projects. Best not to pry."
Sasuke's eyes lingered on him, sharp, calculating. "A weapon?"
Kabuto shook his head faintly, almost smiling. "Not everything here is a weapon."
There was something else behind Kabuto's tone—amusement, maybe, or something closer to warning.
Sasuke cast one last glance at the door, the pulsing quieting again as if aware it was being watched.
He said nothing more, turning away.
But the sound lingered in the back of his mind long after he left the hallway.
---
The ceiling above Sasuke's quarters was rough-hewn stone, the kind that caught candlelight in uneven cracks. He lay on the low cot, eyes tracing shadows that refused to settle.
The pulse behind the sealed door hadn't left his mind.
A knock came—soft, almost polite.
Kabuto let himself in without waiting, a cup of tea balanced in one hand.
"You're restless," Kabuto said mildly.
Sasuke didn't answer, gaze distant.
Kabuto placed the cup on the table, glancing once around the sparse room—the notebooks, the candle, the ever-present emptiness.
"I'd be surprised if you weren't," Kabuto continued. "It's not an easy thing, realizing this place isn't what you thought."
Sasuke shifted slightly. "And what is it?"
Kabuto offered a faint smile. "A crucible. A maze. Depends who you ask."
He folded his arms loosely, the light catching the edges of his glasses.
"You're not the first to wonder why he wastes so much time with riddles and errands. I've wondered the same thing. The others, too. Everyone thinks he's molding weapons. But if you look closely… the pattern doesn't make sense."
Sasuke said nothing.
Kabuto's smile sharpened. "I've seen it long enough. He's not shaping soldiers—he's testing how far we'll walk before we realize the path leads nowhere."
He made it sound like a grand revelation.
Sasuke's eyes narrowed faintly, unreadable.
Kabuto turned toward the door.
"You'll understand, eventually. When the fruit ripens."