He reached twenty-six percent at hour nine.
He knew it precisely because Kurama told him, and Kurama knew it precisely because Kurama had been monitoring the chakra reservoir with the continuous attention of someone who understood that the number was a threshold and thresholds mattered.
The nine hours had passed in the layered way of extended meditation — not uniformly, not linearly, but in the rhythm of depth and surface that serious practice created. He went deep, held the depth until the effort cost exceeded the benefit, returned to surface, rested, went deep again. Each cycle added incrementally to the reservoir, the Uzumaki healing factor working in the background with the consistency of a system that had learned what was being asked of it.
Twenty-six percent.
He sat up from the floor where he had been cross-legged for the last three hours and took stock.
The guest room was grey with early morning light — not yet full dawn, the sky outside at the stage where it had decided to become day but hadn't fully committed. The city noise was at its minimum, the two-to-five AM register where even New York ran at reduced volume.
"FRIDAY," he said.
"Good morning," FRIDAY said. "Your biometrics indicate you've reached a recovery threshold. Mr. Stark asked me to notify him when that happened." A pause. "Should I?"
"Not yet," Naruto said. "Give me an hour."
"Acknowledged."
He needed the hour for the thing he was going to do before he told Tony what he found.
Not because he intended to conceal it from Tony — he didn't, he had no reason to and several reasons not to. But because some things needed to be encountered privately first. Not processed privately, not kept privately. Just encountered. The first reading of a thing that belonged to your own blood felt like it deserved a moment before it became shared information.
He went to the window. Opened it — the building's windows opened, which he had checked on his first night here, the kind of detail that mattered to someone who always wanted to know the exits. The cold morning air moved into the room carrying the city's baseline smell, the particular compound of exhaust and water and ten thousand human activities that had become, in nine days, the smell of the place where he lived.
He sat on the window ledge.
Breathed.
Let the Natural Energy begin its thin accumulation — not the full Sage Mode draw, too demanding at this reserve level, but the passive absorption that came from stillness and intention and the particular receptivity he had spent years developing. Even in New York, in a building made of steel and glass and electromagnetic activity, Natural Energy moved. Slower than in forests. More fragmented. But present.
He let it come.
Then he turned his awareness inward.
At twenty-six percent the depth was different.
At sixteen he had been reading the framework's surface — the distribution network, the broadcast structure, the anchor points of the seal. At twenty-six he moved through those layers the way you moved through a familiar building, not stopping to examine what he already knew, going deeper.
Past the anchor points.
Into the seal boundary itself.
The boundary was — he had no word for it exactly, in either Japanese or English. Old was the closest. Older than old. The specific age of something that had been maintained for so long that the maintenance itself had become part of the structure. He could feel the Uzumaki chakra in it — faded, the color of something left in sunlight too long, but unmistakably Uzumaki. The specific signature of a sealing style he had grown up learning, the same fundamental grammar as the techniques Kushina had taught him, the same underlying principles as the Four Symbols Seal that had held Kurama inside him through his childhood.
But more complex.
More layers than anything he had personally worked with. Not more powerful — complexity and power were different measurements — but more intricate. Someone had built this with extraordinary care over what felt like it might have been a very long time.
He reached the interior boundary.
And stopped.
Because what was on the other side was not what he had been expecting.
He had been expecting something dangerous. Something contained because it needed to be contained — because it was destructive or unstable or threatening in the way that Kurama had been threatening, the way the Ten-Tails had been threatening. Something that required a prison.
What he found was not a prison.
It was a library.
Naruto, Kurama said. The fox's voice was very quiet.
I see it, Naruto said.
What the interior of the seal contained was information.
Not in any medium he could physically read — not scrolls, not stone tablets, not any of the storage formats he was familiar with. It was information encoded in chakra. A massive, structured, organized body of knowledge compressed into a sealed space and held there with the specific intention of preservation rather than imprisonment.
Someone had sealed knowledge into the Uzumaki bloodline.
He moved through it slowly, carefully, the way you moved through a space you didn't want to disturb. The organization was — it was masterful. The information was layered in a way that made navigating it possible even without a map: foundational layers at the base, increasingly specific applications branching upward, the whole structure organized with the logic of someone who had built it to be found and read rather than simply held.
He found the outer layer first. A message.
Not words — chakra signatures organized into meaning, the way advanced sealing communication worked, the way his father had left a message inside his seal for him to find when he needed it. This was the same mechanism. The same intention.
He read it.
It was from Uzumaki Mito.
The message was old. The age of it was in the texture of the chakra — the way old wood felt different from new wood even when both were intact. This was the chakra of someone who had lived a very long time and had died a very long time ago, and had known both things when she built this.
The content took time to read because it was dense and because some of the encoding used variants of the sealing language that had evolved significantly in the generations since Mito had lived. He worked through it slowly, Kurama quiet beside him.
What it said, in the order she had organized it, was this:
She had not been only the wife of Hashirama Senju and the first Jinchuuriki of the Nine-Tails. She had been the keeper of a specific body of Uzumaki knowledge that could not be recorded in physical form because the information itself attracted attention. Not from enemies within the shinobi world. From something outside it.
She had called it by a name that didn't translate directly — the closest equivalent in the language Naruto had grown up speaking was something like the Consuming Attention. A presence, vast and ancient, that was drawn to significant power the way a predator was drawn to movement. That had been aware of the shinobi world — had been circling it, she wrote, for longer than the Uzumaki clan had existed.
She had determined that the knowledge the Uzumaki clan held — specifically the deepest sealing techniques, the ones that operated at the level of dimensional fabric rather than chakra flow — was what the Consuming Attention wanted. Because those techniques could bind it. Could seal it the way the Tailed Beasts had been sealed. Could contain something that had never been contained before.
She had sealed that knowledge into the bloodline itself.
Not to hide it — to protect it across time, regardless of what happened to the Uzumaki physically, regardless of whether any individual carrier knew it was there. As long as an Uzumaki lived, the knowledge lived.
She had included one more thing in the outer message.
A warning.
The Consuming Attention, she wrote, was patient in ways that living things were not. It could wait across centuries. It had waited before. It would find the knowledge eventually if the knowledge was not used first. The seal was not a permanent solution. It was a delay — a very long delay, carefully constructed, but ultimately a delay.
The solution was not containment of the knowledge.
The solution was application.
She had sealed the techniques required to bind the Consuming Attention permanently. When a carrier of the seal who had sufficient chakra capacity and sealing expertise reached them, they would be accessible.
She had ended the outer message with a single line that landed in Naruto's awareness with the specific weight of something that had been aimed at him across a thousand years:
I do not know who you will be when you read this. But you are Uzumaki. That is enough. You already know how to do the impossible. You simply have not been asked to do this particular impossible thing yet.
Naruto surfaced from the meditation slowly.
He came back to the window ledge and the cold morning air and the grey light that had shifted from pre-dawn to actual dawn while he had been inside.
He sat with what he had found for a long time.
Kurama was quiet. Not absent — present, fully present, but giving him the silence the way you gave someone silence when you understood they needed it before words.
Eventually Naruto said: She knew.
She knew something was coming, Kurama said. She didn't know the specifics. But she knew the category.
She built the solution into the bloodline and trusted it would be found by someone who could use it.
Yes.
And whoever built the beacon — the entity outside the galaxy — they knew the knowledge was sealed in the Uzumaki bloodline. That's why they ran the acquisition program. They didn't want the body for the healing factor. Or not only for the healing factor.
They wanted the knowledge, Kurama said. The sealing techniques. The only techniques that can bind the Consuming Attention. They wanted the carrier of those techniques where they could control the activation.
So that when the beacon activated and called the entity here, Naruto said, the knowledge would be accessible. On their terms. Under their conditions.
Rather than yours.
Rather than mine, Naruto confirmed.
He looked at the city.
The dawn light was strengthening, the buildings catching it from the east, the specific transformation of New York in early morning when the light hit the glass facades and the whole skyline did something briefly beautiful that it didn't sustain into full day.
He thought about Mito. About the woman who had carried Kurama before Kushina, who had been the foundation of everything the Jinchuuriki system became. Who had apparently also been keeping a different secret — a larger one, older than the Tailed Beasts, stretching back to something that predated the shinobi world itself.
He thought about Kushina. About whether she had known. About whether she had felt the seal in herself the way he felt the framework now — present, structured, not fully readable but there.
Probably not, he thought. The seal was designed to be invisible to the carrier until accessed. Mito had built it to travel silently. Kushina had probably died not knowing she was carrying it.
He thought about what it meant that he was carrying it now.
In a different dimension. In a borrowed body. Sixteen levels deep in circumstances that Mito could not possibly have anticipated when she built the seal into the bloodline.
And yet here he was.
She said you already know how to do the impossible, Kurama said.
She didn't know what dimension I'd be in when I read it, Naruto said.
No. But she knew you'd be Uzumaki. A pause. And she wasn't wrong about what that means.
Naruto was quiet.
Then he stood up from the window ledge.
"FRIDAY," he said. "Wake Tony."
"Mr. Stark has been awake for two hours," FRIDAY said. "He's in the main workspace. I believe he's been waiting."
Naruto almost smiled.
"Tell him I'm coming down," he said.
Tony was at his screens with coffee and the particular focused dishevelment of someone who had not slept but had been productive during the non-sleeping. He looked up when Naruto came in.
Peter was there too — on the couch, awake, with the look of someone who had been awake for a while in the quiet company of their own thoughts.
Naruto sat down on a stool and told them.
He told it in order — the message from Mito, the sealed knowledge, the Consuming Attention, the purpose of the sealing techniques, the entity's actual objective. He was precise and complete and he did not editorialize because the information was sufficient without editorializing.
When he finished the room was quiet.
Tony was looking at his coffee cup. Not drinking from it. Looking at it with the expression of someone who had built a mental model of a situation and was now rebuilding it around new load-bearing elements.
Peter was looking at Naruto with an expression that had moved through several things and settled on something that was equal parts awe and concern and the particular quality of someone who was trying to hold the scale of what they were hearing.
"The entity," Tony said. "It's not coming for the Infinity Residue."
"The Infinity Residue was the trail it was following," Naruto said. "But the destination was always the bloodline. The sealed techniques."
"It wants the only thing that can stop it," Tony said. "Under its own control."
"Yes."
"Because if the carrier of those techniques is where it can reach them—"
"Then the techniques can't be used against it," Naruto said. "They can be contained. Or corrupted. Or simply kept away from the people who might otherwise use them."
Tony set the coffee cup down. "And Mito's warning. The solution isn't sealing the knowledge. It's using it."
"Using the techniques to bind the entity," Naruto said. "Permanently. The way the Tailed Beasts were bound. The way Kaguya was bound."
"You've bound things before," Peter said.
"Yes."
"Things at that scale."
Naruto thought about the sealing of Kaguya. About the technique that had required both him and Sasuke together, their specific chakra natures combining in the way that only the descendants of Hagoromo's sons could achieve.
"Not alone," he said honestly. "The techniques for something at this scale require a specific configuration. Multiple seal masters. Or—" He paused. "Or a single practitioner at a level of chakra capacity and sealing mastery that compensates for the multiplicity."
"Which is what," Tony said.
"More than I have right now," Naruto said. "Significantly more."
"But you have the techniques," Peter said. "The actual techniques. They're in the seal."
"I have access to them," Naruto said. "Reading the outer message took twenty-six percent chakra and most of my current precision capacity. The techniques themselves are in the deeper layers. I haven't accessed them yet. I'll need to go deeper — and to go deeper I'll need more capacity than twenty-six percent."
"How much," Tony said.
"I don't know yet. I've never read a seal this deep. The outer message was — extensive. The techniques will be at least as dense. Maybe more."
Tony was quiet for a moment. Then: "The modification procedure. Broadcast modification and seal rekeying. Is that still the right play."
Naruto thought about it carefully.
"Yes," he said. "But the objective changes. We're not just misdirecting the broadcast and rekeying the seal to prevent the failsafe. We're rekeying the seal specifically to ensure the sealed knowledge stays under my control. Not the entity's. Not HYDRA's. Mine." He paused. "And the broadcast modification — misdirecting the entity — buys time. But it's not a permanent solution. Mito said the seal was a delay. Misdirecting the broadcast is another delay."
"The permanent solution is using the techniques," Tony said.
"Yes."
"Which you can't do yet."
"No."
"But you'll be able to."
Naruto looked at him steadily. "I've spent fifty years becoming someone who could do impossible things when they were needed. I'm not done yet."
Tony looked at him for a long moment. The recalibrating expression again — but this time it resolved into something more settled. Less like recalibration and more like recognition.
"Okay," he said.
He turned to his screens.
"FRIDAY. Update the modification parameters. New primary objective: rekey the seal anchor points to a configuration keyed to Naruto's specific chakra signature. No other key should work. Not HYDRA's Infinity crystal catalyst, not any external activation mechanism." He paused. "Can we do that."
"The rekeying parameters can be updated," FRIDAY said. "Keying the lock to a specific chakra signature rather than a geometric configuration is a more complex modification. It requires the subject's chakra signature to be embedded in the counter-configuration at the cellular level." A pause. "This will take more chakra to execute than the original rekeying plan."
"How much more," Naruto said.
"Modeling now." A pause. "Original seal rekeying: estimated fifteen to twenty percent chakra expenditure at the cellular level. Updated objective: estimated thirty to thirty-five percent."
"Added to the broadcast modification expenditure," Naruto said.
"Correct. Total estimated expenditure: forty-five to fifty percent."
"Which means I need at least fifty-five percent going in to have a working reserve for contingencies," Naruto said.
Tony looked at the time. "How long to fifty-five."
"At current rate. Twenty hours. Maybe eighteen."
"We have the crystals," Tony said. "HYDRA doesn't. Their timeline is blocked until they recover them or acquire substitutes. Recovery — they know roughly where the crystals are. Substitutes — FRIDAY, how long to acquire equivalent Infinity crystal concentrations."
"Unknown," FRIDAY said. "The crystallization process that produced these appears to have been guided by the entity. Without that guidance, natural Infinity Residue crystallization would take years if it occurred at all. HYDRA cannot replicate the process independently."
"So they come for the crystals," Naruto said.
"Yes," Tony said. "Which means we have a defended window rather than a free window. They'll come in force." He looked at Peter. "You're going to need to make some calls."
"Avengers?" Peter said.
"Avengers," Tony confirmed.
Peter pulled out his phone.
Naruto looked at his hands. Sixteen hours ago he had woken up in a HYDRA laboratory with no idea where he was. Nine days ago he had arrived in this world with nothing. Fifty years before that he had been a child sitting alone in an apartment in Konoha with nothing but the absolute refusal to accept that nothing was all there was.
The scale changed. The distances changed. The specific shape of the impossible thing in front of him changed.
The refusal never changed.
"Tony," he said.
Tony looked up from his screens.
"The deeper layers of the seal," Naruto said. "The actual techniques. When I access them — I'm going to need time and capacity I won't have during the modification procedure. After. After the procedure, after the immediate threat is addressed." He paused. "I'll need to learn the techniques. They were built for someone with Uzumaki sealing mastery that I don't have at that level. I'll need to develop it."
"How long," Tony said.
Naruto thought about what Mito had built. The complexity of the outer message alone. The depth of the organized knowledge below it.
"I don't know," he said honestly. "Months. Maybe more."
Tony absorbed this.
"Then we have time," he said. "We handle the immediate problem first. We give you the time after."
He said it simply, without drama, in the tone of someone making a straightforward logistical commitment.
Naruto looked at him.
"You don't know me," Naruto said. "You've known me for less than two days."
"I know what I've seen in less than two days," Tony said. "I've been wrong about people before. But my error rate is lower than the average." He turned back to his screens. "And I know what Mito apparently knew a thousand years ago. You're Uzumaki. The situation was bad enough that she sealed the only solution