Three days.

Not a long time by most measurements.

The first of them had been, if Nathan was honest with himself, humbling in a way he hadn’t fully anticipated. Stripping back everything he’d built on top of his natural ability and standing in what remained felt like being handed a structure you’d assumed was stone and discovering it was held together by something far more provisional. His footwork, examined properly, was loud. His breathing gave away his exertion in ways he hadn’t noticed because he’d never needed to notice — no opponent had been patient enough, or quiet enough, to use the information. His weight shifts announced his intentions to anyone trained to read them. Layer by layer, Genzo named the habits and Nathan worked to undo them, which was its own particular kind of difficulty. Unlearning sat differently in the body than learning. It had friction.

By the second day, something had begun to move.

Small things. The way he placed his front foot had changed — less commitment in the heel, more distribution across the whole, which turned out to produce a step that was quieter by a degree that surprised him when he first heard it. Or rather, didn’t hear it. Genzo had said nothing, which from him functioned as praise. Nathan had also begun to feel the difference between breathing that powered movement and breathing that announced it — the former drawing inward and tightening the whole system, the latter bleeding energy outward into the air like smoke from a fire that could be tracked by smell.

The third day was where it started to feel less like a series of corrections and more like a language he was beginning to read.

He caught Genzo twice. Not clean hits — not even close to clean — but contacts, actual glancing contacts, in moments where he’d stopped trying to follow the movement and started instead inhabiting the silence around it, letting his body operate on a quieter frequency than usual. The second time, Genzo had paused and looked at him with the expression of a man making a private notation.

But then he’d stopped the exchange.

The sound reached Nathan before he saw it.

A cascade — heavy and continuous, the kind of white noise that filled a space so completely it became the space rather than something in it. Genzo led him through the forest to where the terrain dropped and the water came off the rock face in a single sustained column, wide and powerful, falling into the basin below with a force that sent permanent mist drifting across the surrounding ground. The trees here were dark with moisture. The stone beneath was black and slick.

Genzo stopped at the basin’s edge and turned.

"Here," he said. "Before we go further."

Nathan looked at the cascade. Then at Genzo. "You want me to sit under that."

"I want you to sit in front of it." Genzo indicated a flat shelf of rock positioned perhaps eight feet from the falling water — close enough that the mist settled on skin immediately, close enough that conversation required projection over the noise. "Cross-legged. Hands on your knees. And I want you to breathe."

Nathan pulled his shirt over his head and folded it, set it aside, and stepped onto the rock shelf. He lowered himself into the position — cross-legged, back straight, hands resting open on his knees — and looked out at the curtain of falling water in front of him. The mist was cold. Consistent. It found every surface of his bare torso and stayed there, and beneath the bandaging at his neck the bite pulsed its familiar complaint about the temperature.

He ignored it.

Genzo positioned himself at the edge of the shelf, standing, hands folded behind his back. He looked at Nathan.

"Your breathing up to now has been a tool you use when you remember to," Genzo said, pitching his voice to carry clearly over the water. "A mechanism for managing exertion. You breathe harder when you push harder. You control it when you think to control it." He paused. "That is functional. It is also a ceiling."

Nathan said nothing. He watched the water fall.

"A shinobi’s breath is not a response to the body," Genzo continued. "It is the body’s foundation. The root everything else grows from. Your movement, your silence, your ability to disappear from a man’s awareness while standing directly in front of him — all of it begins here." He touched two fingers briefly to his own sternum. "Breath that is controlled does not mean breath that is suppressed. It means breath that costs nothing — that runs beneath everything else like water beneath the ground. Present. Continuous. Noticed by no one, including yourself."

The cascade filled the silence between sentences with its unchanging voice.

"Close your eyes," Genzo said.

Nathan closed them.

"Breathe in. Count four. Hold. Count four. Out. Count four. Hold. Count four." A pause. "Do not think about the count. Think about the quality of the air entering you. Think about where you feel it stop."

Nathan breathed.

In — held — out — held.

Simple on the surface. The kind of thing that sounded almost dismissively basic until you actually attempted it with full attention and discovered that the mind, given a structure that simple, immediately began filling the available space with everything it normally drowned out. The burn at the neck. The mist on his shoulders. The sound of the water broken into its individual components — the main column, the secondary splashing at the basin, the finer mist-fall against the stone. Genzo’s presence a few feet to his right, breath and weight barely perceptible but there.

"Your shoulders just rose," Genzo said.

Nathan lowered them.

"Breath that lives in the shoulders tells everyone watching you that you are working," Genzo said. "Breath that lives in the belly tells no one anything. Find the belly. Keep it there."

Nathan redirected. Felt the adjustment as a physical thing — the expansion moving lower in his torso, filling differently, the shoulders staying still and quiet above it all.

"Good," Genzo said. "Again."

The water fell without pause or preference.

"The reason this matters beyond silence," Genzo continued, after several cycles had passed, "is that breath is the bridge between what the body does and what the mind decides. When the breath breaks — when it responds to fear, to pain, to surprise — the bridge collapses. And a man with a collapsed bridge between his body and his mind is a man reacting, not fighting. He is always one step behind himself." He let that sit. "You have good instincts. We have established that. But instincts operating through panicked breath are half an instinct. Instincts operating through controlled breath are something else entirely."

Nathan sat with the water and the mist and the cold settling across his shoulders and breathed.

In. Hold. Out. Hold.

He could feel, with each cycle, the poison doing its background work — the dull pulse at the neck, the faint radiating heat that never fully left. But there was something in the breathing rhythm that related to it differently than ordinary endurance did. Not suppression — he wasn’t fighting it, wasn’t tensing against it. Just placing breath between himself and the sensation, letting the rhythm run underneath it like the current Genzo had described.

He understood, sitting on that wet stone with the cascade filling the world, why this came before everything else.

You couldn’t build silence on a noisy foundation.

"How long?" he asked, without opening his eyes.

"Until it stops being something you do," Genzo replied, "and becomes something you are."

The water fell.

And Nathan breathed.

Genzo was not a man who smiled often or without reason.

He was aware of this about himself — had been aware of it for long enough that it had stopped being a observation and become simply a fact, like the way the forest smelled after rain or the weight of a blade held correctly. Smiling required something to smile at, and most things, in his experience, did not meet that threshold.

Nathan apparently did.

He watched the younger man on the rock shelf — bare-shouldered, mist-damp, the bandaging at his neck the only visible evidence of everything his body was quietly fighting through.

No performance. No impatience leaking out at the edges despite the personality Genzo had already catalogued well enough to know impatience was native to it. Just the work, taken seriously, because Nathan understood — had understood from the first correction — that the work was worth being serious about.

Three days. Three days of being taken apart and rebuilt in small increments, and already the quality of his movement had shifted in ways that most men Genzo had trained didn’t achieve in three weeks. The absorption was almost unsettling in how clean it was — not just the physical corrections landing and sticking, but the understanding behind them arriving simultaneously, so that Nathan wasn’t merely imitating the adjustment but grasping why it existed and where it connected to everything else. He corrected himself between sessions. Genzo had noticed that — had seen Nathan standing alone near the tree line the previous evening, running footwork patterns quietly, testing the sound of his own steps against the silence he was learning to aim for.

A genius was perhaps too simple a word. But it was the one that kept presenting itself.

Genzo allowed himself the smile.

He was not the only one watching.

Yukihime sat on a rock at the field’s edge with her hands folded in her lap and her black eyes resting on Nathan’s form with an attention that had not wavered once across the entire three days — not restless, not distracted, simply present and constant in the way that very few things were constant in Genzo’s experience. She was smiling faintly as she watched him.

Genzo had seen devotion before but this seemed even deeper than that.

He wondered, not for the first time, what Nathan had done to earn it.

He suspected the answer was simply that Nathan had seen her. Fully and without flinching, which was, in Genzo’s observation, rarer than most people acknowledged.

"It’s rare to see you smile, Uncle."

The voice arrived from directly beside him.

Not from approaching footsteps — there had been none. Not from any displacement of air or shift in the peripheral world that might have announced a presence drawing near. The voice simply existed next to him where no voice had been a moment before, as natural as if it had always been there and he’d only just noticed it.

Genzo turned his head without hurry.

She stood at his right — dressed entirely in black, the lower half of her face covered, only her eyes and the line of her forehead visible above the cloth. Dark hair pulled back from her face into a severe tail at the nape of her neck and with calm grey eyes assessing the place.

His niece. His brother’s only daughter. The last living piece of someone he had lost in ways that still occasionally found him in quiet moments and made themselves felt.

"Hanzo." A slight inclination of his head. "You’re back."

She nodded once. Her gaze had already moved past him to Nathan.

"Any complications?" Genzo asked.

"No," she said. "They’re all dead."

Of course they were. He hadn’t genuinely wondered — had asked as formality rather than inquiry. She was the finest shinobi he had known in his life, himself included, though he would only admit the second half of that assessment in his own private thoughts. She completed her missions the way water completed its path downhill.

"You were gone for most of it," Genzo said, his eyes returning to Nathan on the rock shelf. "The arrival. Everything that followed."

"I was informed," she replied. "Thoroughly."

"Then you know what we have," he said. "And what we’re preparing for. We have obtained a powerful ally."

Hanzo said nothing for a moment. Her grey eyes stayed on Nathan — on the still, bare-shouldered figure in the mist, the controlled breathing visible in the rise and fall of his toned chest.

"Powerful ally," she said at last. "That may be understating it."