Laboratory Intruder

The underground passage was deeper than expected.

Hyuga Xiao kept his Byakugan at maximum range in the darkness, chakra flowing slowly through his meridians. Every step he took was soundless. Scorch marks left by Lightning Release covered the cave walls, and the air was thick with a mixture of ozone and blood—the distinctive traces of battle left by Hidden Cloud ninja.

The deeper he went, the colder it became.

Signs of artificial excavation began to appear on the rock walls, along with faint, rough rune carvings. Xiao's gaze pierced through three layers of rock and saw an underground space three hundred meters ahead—a circular laboratory over fifty meters in diameter. Glowing crystals were embedded in its dome, metal grating covered the floor, and three cylindrical incubation tanks stood in the center.

The incubation tanks were already empty. Their glass had shattered, and nutrient fluid had spread across the floor in thick, pale green puddles.

And there were three people in the laboratory.

Xiao stopped, pressing himself against an indentation in the rock wall. He suppressed his chakra until it was nearly imperceptible. Through his Byakugan, the flow of chakra in all three people was clear—they were all Hidden Cloud Village Lightning Release ninja, each with chakra reserves at least at the Elite Ninja level.

One of them was half-kneeling before the central control console, his right hand pressed against a dark red Curse Mark rune on its surface.

"Captain, this thing is absorbing my chakra!" The young ninja's voice trembled with restrained fear.

"Don't let go, Takuya." The middle-aged man standing behind him spoke in a low voice. "This is a sealing formula set by Orochimaru. We have to continuously suppress it with chakra to remove the data protection. Hold on for another thirty seconds."

"But..."

"No buts." The third person stood guard at the laboratory entrance. She was a tall female ninja with an icy voice. "We already triggered the outer Curse Mark traps. Orochimaru's subordinates could arrive at any time. Takuya, if you can't hold on, the captain and I will take the data and retreat first."

Half-kneeling, Takuya clenched his teeth as the muscles in his arm began twitching unnaturally.

Xiao's pupils contracted slightly.

Through the Byakugan, he saw the dark red Curse Mark spreading up Takuya's arm, burrowing beneath his skin like a living thing and tangling with his meridians. This was no simple sealing formula—it was some kind of biological parasitic Curse Mark, one that was altering the host's physical structure.

"Captain... my arm..." Takuya's voice became hoarse.

The middle-aged captain bent down to examine him, and his expression changed drastically. "Damn it, this isn't a sealing formula. It's a bait trap! Takuya, cut off your chakra supply immediately!"

But it was already too late.

Countless tiny lumps of flesh swelled beneath Takuya's arm. They expanded at a visible speed, burst apart, and released dark red, tentacle-like tissue. The tendrils coiled around his arm and crept toward his shoulder, turning the skin they passed over a grayish-brown texture like bark.

"Ah—!"

Takuya let out a pained howl and sprang from the ground, his body twisting into a grotesque arc in midair. His right arm had completely mutated, swelling to three times its original thickness. His five fingers had fused into three thick claws, corrosive mucus dripping from their tips.

"Captain, what do we do?" The female ninja had already drawn the short blade from her back, blue lightning flickering over its edge.

The middle-aged captain stepped back two paces and rapidly formed hand seals. "Takuya can't be saved. Yumi, prepare to carry out the elimination procedure."

"But—"

"That's an order!" The captain's voice was final. "Once Orochimaru's Curse Mark enters its second stage, the host will completely lose their reason and become a monster that knows only slaughter. We can't let something like that leave here alive."

Yumi bit her lip, and the lightning on her short blade blazed brighter.

At that moment, the mutated Takuya slowly turned around.

His right eye had become a murky dark red. His left still retained a human pupil, but his gaze was filled with pain and madness. His mutated right arm dragged across the ground, its claws scraping over the metal grating with a piercing screech.

"Cap... tain..." Broken syllables squeezed from Takuya's throat. "Save... me..."

"I'm sorry, Takuya." The captain closed his eyes. When he opened them again, his gaze was cold as iron. "Lightning Release: Lightning Binding Coffin!"

Dozens of bolts of lightning erupted from the ground, forming a cage around Takuya. When the lightning struck his mutated arm, it crackled explosively, filling the air with the stench of scorched flesh.

Takuya let out an inhuman roar and slammed his mutated arm into the lightning cage.

Boom!

The lightning exploded, and a gap was ripped open in the cage by brute force. Takuya broke free and lunged at the captain, moving at least three times faster than before his mutation.

"So fast!" Yumi raised her blade to block him in front of the captain. Her short blade collided with the claws, and lightning and dark red chakra exploded into a ring-shaped shockwave.

The metal grating floor hummed violently.

Xiao watched silently from the darkness.

His gaze did not linger on the battle. Instead, he swept his eyes across the entire laboratory. Behind the control console was a hidden safe. Its door had already been cut open by some high-intensity Lightning Release, and it was completely empty. But in a corner of the floor lay several scattered paper documents, as well as...

A silver sealed container.

The container was about the size of a fist, its surface etched with intricate sealing runes. Through the Byakugan, Xiao saw a dark red crystal floating inside. Liquid-like chakra flowed slowly within it, constantly changing shape—at times like a seed, at others like an embryo.

Active Curse Mark Seed.

The term flashed through Xiao's mind. Orochimaru's research materials had mentioned it before. It was the core product of Curse Mark technology, capable of being directly implanted into a ninja's body to create controllable Curse Mark warriors in a short time. If he could analyze its structure, perhaps he could reverse-engineer the weakness of the Caged Bird Seal.

By now, the battle in the laboratory had reached its most intense stage.

Yumi's short blade had left more than a dozen wounds on Takuya, but those wounds healed at a visible rate, and the mutated tissue only swelled further. The captain's Lightning Release techniques struck him again and again, yet could only slow Takuya's assault.

"Captain, this can't go on!" Yumi panted as she retreated. Her left shoulder had been grazed by a claw, leaving a wound deep enough to expose bone. "His recovery speed is too fast!"

The captain's expression darkened as his eyes swept across the laboratory. "We have to find the Curse Mark's core weakness. Orochimaru's research materials must have records—"

His gaze suddenly fixed on the silver container on the floor.

At almost the same moment, Xiao moved as well.

Rather than rushing toward the container, he retreated three steps, completely merging into the shadow of the rock wall. He suppressed his chakra to the limit, until even his breathing became nearly nonexistent.

Because he saw that the mutated Takuya had suddenly stopped attacking.

Takuya stood where he was, his mutated arm slowly lowering. His dark red eyes stared fixedly at the captain, and an eerie smile spread across his lips.

"Captain..." Takuya's voice became unusually clear, even carrying a mocking tone. "Do you think... I really lost my mind?"

The captain and Yumi froze at the same time.

"The Curse Mark is indeed eroding my body." Takuya raised his mutated arm, its claws opening and closing softly. "But it has also given me power... power like never before. I saw it, Captain. I saw the look in your eyes just now—as if you were looking at a tool about to be discarded."

"Takuya, you—"

"Don't call me by my name!" Takuya suddenly roared, his voice making the crystals in the laboratory dome tremble. "In the Hidden Cloud, what are ordinary Elite Ninja like me? Pawns to be sacrificed at any time? Scapegoats when a mission fails? For this mission, you never planned to let me return alive from the beginning, did you?"

The captain's face became extremely ugly.

Yumi gripped her short blade and said quietly, "Captain, he's stalling for time. The Curse Mark is eroding his brain. This is his final burst of clarity."

"I know." The captain took a deep breath and began forming more complicated hand seals. "Yumi, prepare that technique. Activate it together in three seconds."

"Yes."

But Takuya laughed.

That laughter was full of madness and despair. "Too late."

He suddenly turned—not toward the captain, but toward the silver container on the floor!

"Don't even think about it!" the captain roared, completing his hand seals. "Lightning Release: Lightning Tiger Massacre!"

A fierce tiger made of lightning burst from the captain's hands and pounced at Takuya's back. At the same time, Yumi threw her short blade. Wrapped in blinding lightning, it shot straight for Takuya's neck.

But Takuya did not dodge at all.

He shielded his back with his mutated arm and endured the Lightning Tiger's impact head-on. He was blasted flying, the flesh on his back torn to a pulp. Yet using that force, he threw himself toward the silver container and snatched it up with his claws.

The short blade pierced his shoulder, but he paid it no heed.

"Captain..." Takuya dropped to his knees and raised the container with his last human left hand, his dark red eyes fixed on the captain. "This thing... I won't give it to you even if I die..."

Before his words had faded, he violently smashed the container toward the ground!

"No!" The captain's eyes nearly split with rage.

Just as the container was about to hit the ground—

A blurred figure flashed out from the shadows.

So fast that even an afterimage was barely visible.

The figure caught the container a tenth of a second before it hit the ground, then kicked Takuya in the chest. The force of that kick was controlled with extreme precision—it did not kill Takuya, but sent him flying backward straight into the charging captain and Yumi.

The captain instinctively caught Takuya, while the figure had already vanished into the passageway on the other side of the laboratory.

The entire process took less than two seconds.

"Chase him!" The captain shoved aside the unconscious Takuya and was about to rush out.

But Yumi grabbed him. "Captain, wait! That person's speed just now... did you see his eyes?"

The captain froze.

"White eyes, no pupils." Yumi's voice trembled slightly. "That was the Byakugan of Leaf Village's Hyuga Clan. And we never noticed where he appeared from before—meaning he had been lying in wait for at least five minutes."

Cold sweat seeped down the captain's back.

Someone who could hide for five minutes from the senses of three Hidden Cloud Elite Ninja, then strike at their most relaxed moment and seize the target...

"Since when did Leaf Village's Hyuga produce someone like this?" the captain said through gritted teeth. "The mission has failed. Retreat immediately. Take Takuya with us... he still has research value."

"What about the container—"

"It's gone." The captain looked into the depths of the passage, his eyes sinister. "But at least we now know that inside Leaf Village... things aren't peaceful either."

Five hundred meters deeper into the passage.

Hyuga Xiao stopped with his back against the rock wall and slowly let out a breath.

The silver container in his right hand was icy cold, its sealing runes still glowing faintly. He carefully scanned it with his Byakugan. Only after confirming that the container had no tracking or self-destruct mechanism did he place it into the ninja tool pouch at his waist.

Making his move just now had been risky.

If those three Hidden Cloud ninja had reacted just a little faster, if Takuya had chosen to self-destruct before dying, if there had been more hidden traps in the laboratory...

But it had been worth it.

Xiao closed his eyes and recalled every detail he had observed. Takuya's mutation process, the rate at which the Curse Mark eroded him, the suspicion and betrayal between the Hidden Cloud ninja. All of it was valuable data—about Curse Marks, and about human nature.

[ Ding! High-purity Curse Mark creation "Active Curse Mark Seed" detected. Analyzing... ]

The system notification rang in his mind.

[ Analysis complete. This creation contains the core data of Orochimaru's improved "Curse Mark of Heaven," with 17.3% structural similarity to the "Caged Bird Seal." Consume 500 Destiny Points for in-depth analysis? ]

Xiao did not make a choice immediately.

He opened his eyes again and looked back in the direction he had come from with his Byakugan. The three Hidden Cloud ninja had already retreated with the unconscious Takuya, and silence had returned to the laboratory. But the lingering chakra fluctuations in the air, along with the documents scattered across the floor, proved that another group of visitors would arrive here soon.

Orochimaru's subordinates, or... Leaf Village's ANBU.

Xiao turned and headed deeper into the passage.

Since he was already here, he could not leave with only one container. Orochimaru's research materials concerning the God Tree and Curse Marks surely contained something even more valuable among those paper documents. And besides...

His gaze pierced through three layers of rock wall, and he saw another hidden level beneath the laboratory.

An incubation tank in that hidden level was still operating.

Submerged within the tank was a pale human body. On that person's forehead was carved the Caged Bird Seal of the Hyuga Clan.

Xiao's steps paused slightly.

Then he accelerated, slipping toward the hidden entrance.

The crystals in the rock walls cast a cold light, stretching his shadow long behind him. From deep within the passage came the sound of water droplets striking the ground: drip, drip, drip, like some kind of countdown.

And inside the ninja tool pouch at his waist, the dark red crystal within the silver container was slowly pulsing.

Like a living heart.