The instant the stone cabinet's metal door was welded shut, it gave a dull click and interlocked with the outer sealing formation, preventing even a trace of chakra fluctuation from leaking out.
Rinto crouched before the blastproof stone cabinet in the deepest part of the laboratory, an extremely fine thread of chakra gathered at his fingertips as he performed the final tests on each layer of seals. This was already the sixteenth layer he had laid. From the outermost camouflage seal to the soul-locking formation and anti-tampering barrier in the middle, then to the self-destruct anchor at the very core, the layers nested within one another, with any disturbance affecting the whole.
Locked inside the stone cabinet was all the work he had poured himself into over the years since escaping Konoha. His core experimental records, the diagrams from every trial and error, the fragmentary scrolls from the Land of Whirlpools, the Dust Release insights Ōnoki had given him, and even his discarded drafts-he had arranged them all neatly in chronological order and sealed them inside waterproof metal boxes.
"Fuck, the signals are crossing again."
He cursed under his breath and withdrew the chakra from his fingertips. During the test just now, the inner locking seal and outer alarm formation had triggered a linked response, nearly setting off the self-destruct mechanism by mistake. Patiently, he revised the linkage logic between the two seals and readjusted their activation thresholds, ensuring that the countermeasures would only activate layer by layer during a forced breach. The self-destruct anchor at the very core would activate only if chakra other than his own forcibly touched the cabinet's inner core-once triggered, the entire underground laboratory would instantly be blasted to ashes. Never mind the records; not even a single intact stone would remain.
He spent an entire day on it.
He had originally thought he could finish the seals in half a day. Only when he actually started did he discover how much of a pain it was to account for theft, destruction, and accidental activation while also linking them to the entire island's Martyrdom Sealing. As he crouched on the ground revising the sealing patterns, he thought irritably more than once that if he had known he would be leaving for so long, he should have finished all of this when he first built the laboratory. Then he would not have had to waste so much time now.
But however irritating it was, it had to be done. These records mattered more than his life. Even if something happened to him outside, they absolutely could not fall into the hands of Danzo, Orochimaru, or anyone who wanted to turn his techniques into weapons of war.
Only after he had finished the cabinet's seals and tested them more than a dozen times to confirm there were no flaws did he brace himself and stand on numb legs, stretching his stiff lower back. It had long since gone dark outside the window, and most of the oil in the lamp had burned away. Only then did he remember that he had eaten just half a dry flatbread since morning.
The dry flatbread beside the table had long since become hard enough to hurt his teeth. He picked it up, took a bite, and washed it down with cold water. After finishing it in a few bites, he turned, picked up his engraving knife and materials, and left the laboratory.
Next came upgrading the entire island's defenses.
The previous defenses had been intended to keep people from intruding and disturbing his research. Now he needed to modify them to prevent people from establishing a long-term foothold or forcing their way into the core area. Even if he left for six months or a year, this island had to remain a tough nut that no one could crack casually.
He followed the existing defensive line, modifying it one point at a time. At the outer sensory anchors, he extended the warning perimeter another two nautical miles and even added underwater-triggered traps to the seabed to prevent anyone from sneaking in beneath the water; in the middle trap belt, he linked the existing paralyzing Lightning Release and Explosion Release traps to the killing formations of the Martyrdom Sealing, so that once triggered, the entire belt would activate rather than a single trap, making even a team of Jonin pay dearly for breaking in; the inner barrier connected directly to the core of the Martyrdom Sealing, and anyone forcing their way through would immediately trigger the Martyrdom Formation's spatial counterattack. It was not a question of whether it could trap someone-it could sweep them straight into another dimension.
For the laboratory area at the very core, he laid a separate closed-loop sealing system. The stone door was sealed shut and linked to the formation nodes across the island. If anyone dared to force it open, the entire laboratory would immediately self-destruct, serving as a backup to the stone cabinet's self-destruct anchor and vice versa-a double safeguard.
These modifications took him another two full days.
By day, he ran all over the island beneath the sun, modifying anchors, adjusting seals, and testing their linkages. At night, he returned to his makeshift shelter and revised diagrams by lamplight, adjusting the seals' linkage logic. Once, while modifying the Martyrdom Sealing's linkages, he accidentally touched the patterns of an existing killing formation. More than a dozen wind blades instantly shot out of the ground. He reacted quickly and blocked them with Earth Release, but flying rubble still cut him. He was so angry that he cursed for ages, then crouched right there and dismantled and reengraved every pattern in that area.
Once the entire island's defenses had been upgraded, he walked a circuit of the island and activated its full sensory network. Only after confirming that every anchor was functioning normally, every trap could trigger precisely, and every barrier layer was properly linked to the Martyrdom Formation did he finally breathe a sigh of relief.
Even in his absence, the island could now protect everything he had built up.
Next came packing the luggage he would take along.
He did not bring much. His modest waterproof backpack was stuffed full, entirely with research-related items. In the compartment closest to his body, he placed an abridged version of his core experimental records, the fragmentary Yin-Yang Release scroll from the Land of Whirlpools, Ōnoki's Dust Release insights, and his core diagrams for the Senjutsu cycle and anchor reconstruction. He wrapped them in layer after layer of oilcloth, afraid they might get wet or damaged.
Then came his engraving knives. He brought six in various sizes, all familiar tools, along with high-density sealing metal plates, chakra-conducting fluid, emergency sealing talismans, and medicine for treating wounds, filling nearly half the backpack.
As for everyday necessities, he brought pitifully few. Two changes of clothes, a water dipper, and a small bag of compressed dry rations. He filled all the remaining space with consumables related to research and sealing. He did not even bring a tent, considering it a waste of space. In his view, while traveling, he could make do for a night in any cave or patch of woods. There was no need to bring useless things that would slow him down and make him easier to spot.
After packing, he sat on the stone platform, took out the little notebook he carried, and began planning his route.
To find information on Yin-Yang Release, he first had to rule out several places. Konoha was absolutely out of the question. Danzo's Root was watching for him. Once he stepped inside, he could forget about researching in peace; there would only be endless trouble. Orochimaru's bases were even more out of the question. He disdained touching Orochimaru's human experimentation records, and going there would mean getting entangled with Orochimaru, with no way to shake him off. The great nations' shinobi villages, such as Iwagakure, Kirigakure, and Kumogakure, were even less viable. Once he went in, he could forget about getting out. They wanted his technology, not to let him conduct research.
That left only the neutral territories of the shinobi world and the small nations with secret traditions.
He chose Falling Sand Town in the Land of Rivers as his first stop. It was one of the shinobi world's largest black-market hubs, a mixed crowd with plenty of information. As long as he had money, he could unearth all sorts of lost fragmentary scrolls and records of secret teachings. He might find clues about Yin-Yang Release. Moreover, the Land of Rivers was neutral, and Konoha's control there was weak. Although the major shinobi villages had plenty of spies there, he would not be easily targeted as long as he concealed his identity. It presented the lowest risk.
If he found nothing useful in Falling Sand Town, he would move on to the surrounding small nations. He had previously heard that the Land of Waterfalls had secret body-energy techniques passed down through generations; perhaps they could bring him within reach of Yang Release. The priestesses' secret teachings in the Land of Hot Water included quite a few related to spiritual energy, so he might find clues about Yin Release there. There were also the Land of Bears and the Land of Grass. These small nations all had their own secret teachings. Even if he could not find core records of Yin-Yang Release, he could still fill the gaps in his understanding of chakra's origins.
As for the Fire Temple in the Land of Fire, he had heard it contained murals of the Sage of Six Paths and might have records of Yin-Yang Release. But it was too close to Konoha, and the risk was too high. He would keep it as a backup for now and stay away unless he had absolutely no other choice.
With his route decided, he closed the notebook and tucked it into his clothes. There was no hesitation or agonizing. To him, where he went did not matter, and safety was not his highest priority either. Whether he could find the information he wanted and conduct research without being disturbed were his only criteria.
The night before departure, he sealed all the remaining materials in the laboratory, the unused metal plates, and the books he was not taking into the adjacent secret storeroom. He laid the same seals as on the stone cabinet and linked them to the island's defenses. Then he completely sealed the laboratory's stone door and covered the outside with rock, making it blend into the surrounding rock face. Without a careful search, no one would discover an underground laboratory there.
Early the next morning, just as the sky began to lighten, he shouldered his backpack and walked to the beach on the island's eastern side.
He did not seek out the fishing boat from before. It was too conspicuous and too slow. Raising a hand, he used Earth Release to create a moderately sized single-masted boat. He made the hull narrow to reduce drag and engraved several sets of Wind Release propulsion anchors into its underside. It would be much faster and more discreet than rowing. He also added sealing patterns that disrupted sensing, making the boat impossible to detect with long-range Sensory Ninjutsu.
He put his backpack in the cabin, pushed the boat into the sea, and vaulted aboard. The Wind Release anchors beneath the hull activated, and the little boat shot toward the southern coastline like an arrow loosed from a bow.
Rinto stood at the stern and glanced back.
The deserted island in the Land of Whirlpools grew ever more distant. The rock faces he had covered in anchors, the laboratory where he had spent years, and the reefs where he had tested countless techniques slowly shrank into a tiny dot on the horizon before disappearing completely.
He felt no particular reluctance to leave. The island was merely a place to conduct research. As long as he still had his mind, his diagrams, and his records, he could conduct research anywhere.
Withdrawing his gaze, he turned to look at the distant coastline. The sea breeze carried a salty, fishy smell and made his clothes snap in the wind. He paid it no mind, turned, and ducked into the cabin. Taking out his little notebook and charcoal pencil, he began sketching his preliminary ideas about Yin-Yang Release in the morning light.
Even while traveling, he did not want to waste a moment.
He did not think much about what lay ahead. Whether Konoha's people would target him, whether he would encounter Orochimaru's people, or whether the Akatsuki would set their sights on him-he cared about none of it. If trouble came, he would beat it back. If he could not win, he would move somewhere else and continue his research.
As long as it could bring him within reach of chakra's essence, he would dare to venture ahead even through mountains of blades and seas of fire.
The little boat sped across the sea, and the Land of Whirlpools behind him vanished completely beyond the horizon. The road ahead was full of unknowns and trouble, but his eyes held only the half-finished anchor concept for Yin-Yang Release sketched in his notebook.