Kasai: Conflagration; fire.

Kesshi: Hero; preparedness for death.

The Chaos Theory

"This seal allows you to store and compress chakra over a long period of time. Each time you access it, your life span is significantly shortened." Tsunade raised her saucer and indulged in a long sip of sake. When she lowered it, she noticed her apprentice had paled. "You are never to use this technique unless your life is on the line. I am passing it on to you because I trust you, Sakura. I trust your judgement."

For a long moment, the pink-haired teen was silent, dithering. She bit her lip, almost as though she did not trust herself as her master did.

The Genesis of Rebirth was a technique carried through one expert and one inheritor. It offered not only healing, but regeneration—a period of immortality during battle.

Tsunade acknowledged the fact that she was altering the timeline by teaching it to Sakura. But how could she not? The technique could not die, not so young in its usage. What if it could make a difference in battle, in whatever it was the time travelers had run from?

The only question was as to whether Sakura would use it excessively, after inheriting it so young. Would Sakura neglect the fact that the value of her life far outweighed her worth as a martyr?

Tsunade could only trust that she wouldn't. Genzai Sakura had no need for the technique at least for the next ten years, as her counterpart was still alive and well without adorning the diamond seal on her forehead.

Across the office, Genzai Sakura's downcast eyes lifted to meet her mentor's. "I am honored, Tsunade-sama." The girl lowered herself to her knees on the cold tiled floor. "Please show me the technique."

Chapter 13

The girl looked to be six or seven, with long black hair, longer than Kasai's. It trailed down to her lower back, two thick locks in the front framing her face before her head band. She was wearing a strapless red dress—very girly—and had fair skin, stubborn cheeks, and a smile that was warm and genuine. It was an infectious smile like Sakura's, not an aggressive one like Kasai's.

Her nose was Sakura's, her lips were Sakura's, her shy grin and little feet, and—

Everything else was Sasuke's. The teeth, the skin...those onyx eyes that would awake the sharingan.

It was the first time Hinata had seen her husband drop his sword.

"Where's Kasai?" she heard herself say, her voice small and hollow, not unlike her young counterpart's.

A confused moue pulled at Kesshi's lips. "Kasai?" she enunciated with careful consideration. "Who's that?"

Mirai Hinata turned and walked into Kasai's room again, expecting to suddenly find the bed unmade, the window open, clothing laying rumpled across the floor. But everything was pristine. There were no toys or childrens clothes, and only one imprint on the right side of the bed, as though she and Kasai had not laid curled together the previous evening.

Hinata brought her hand to her face, breathing thinly; hyperventilating, like she was a teenager again. It was almost funny. She leaned against the wall because the world was tilting. She allowed herself to sink down to the floor.

Sasuke always told her to take deep breaths.

On the contrary, she shook with sobs, tears rolling freely down her cheeks. She couldn't—couldn't—survive this. It was too much. It was—she couldn't. After everything. The door opened, yet she could hardly process it.

Someone sat beside her, pulled her into their arms.

"She's gone," Hinata choked out.

"Don't," said Sasuke quietly. His hand trembled slightly, and it intrigued her. Yet he ran it through her hair, to comfort her, as was his wont. Because he was stronger.

She tried to get up, but he held her tightly, keeping her in place.

"Please stay," Sasuke entreated, and he had never sounded so feeble. He took her hand.

"I'm going to be sick."

"Mm."

So she sat there, blank-faced, and considered things. Her tears ran till her cheeks burned. Kasai was now gone, and replaced by Kesshi, a child who was not hers, in fact, appearing to be Sakura's. And Sasuke's.

When they returned to their time, would Sasuke and Sakura be together? Would Hinata and Sasuke lose their memories of being married, and having Kasai? Or would they remember it all? And which would be worse?

"I dreamt of this," Hinata mumbled. "Every night I s-seem to h-have these dreams. Of our world. But d-different. And last night…l-last night, I dreamt of Kesshi."

Sasuke said nothing, but his fingers paused on her temple, and perhaps he also recalled her newfound habit of activating the byakugan in her sleep.

Hinata took a shuddering breath. "You should have let me."

"Kill Hana?" said Sasuke with a weak scoff. "It's irrelevant. It won't fix things."

"It will fix enough," said Hinata sharply.

Hating Hanabi made her stronger. She had not sacrificed her love for Hanabi on a whim. In fact, it had been to her benefit. She now had the ability to hate her sister without hindrance, and by extension, the opportunity to kill her.

"It won't bring back Kasai."

Hinata was cowed by this reality.

She could feel the electricity of Sasuke's chakra, galvanizing his body with tension, thrumming under his skin. Despite the façade of control, his emotions seeped through the bond between them, as shrunken and frail as they were. He was broken.

"We've been wasting t-time here," Hinata went on. "M-messing everything up. This is your fault, this is—" She scrambled away from him and retched in a corner. She coughed a few times, then heaved again.

Now the room was spinning. She climbed to her feet, but Sasuke followed, supporting her.

"Let go," she said. "I'm fine." Her voice was a choked whimper.

"Hinata."

"I just want to train."

"You're not stable."

"That's a bonus, you know," she laughed. "Well of course you know." She wanted to get away from him. He disgusted her. The pig. The animal.

"I'm sorry."

"I know that Sakura and I are interchangeable to you," Hinata forced out with a bitter smile. "But I just—I need my daughter. The only thing I'll ever need is her." She could hardly see him. He was just a blur through her puffy eyes. She tried to pull away, but found herself instead buried in his shirt. Why did she always allow him to overpower her? He was a fucking, fucking thing. A worm. I hate you.

"I know."

She sobbed, "You should have let me."

"Breathe," he urged her.

Capitulating, she breathed in the scents of earth and amber. She inhaled once, twice, then released. She took another long draw, forcing oxygen in her lungs, until her chest stilled and the world was no longer furiously quavering.

It had not, by any means, improved things.

Mirai Naruto knelt beside Hanabi with soothing, apologetic murmurs. He heard himself say things about "night terrors," "stress," and "trauma." He apologized for Hinata's behavior, and closed with, "we've all been through a lot." Yet his mind couldn't have been further from his false assurances.

Hyuuga Hanabi gave a curt nod. "Fine," she said, askance. She was still curled on the floor and somewhat shaky. His pale eyes darted to Sakura, then the little girl.

"If you need me to speak to your father…" Naruto feigned.

"I said it's fine," Hanabi repeated tartly. She got up and brushed herself off, as though Mirai Hinata's attempt to murder of her had been a trivial hazard of adolescence. With one more haughty look, she walked off, her usually neutral visage turned in a frown.

"Okaasan, what's wrong?" Kesshi tugged on Sakura's shirt sleeve.

Naruto turned to them, a bit stunned.

Sakura was visibly shaken. "Nothing…honey," she managed. "I need to—to talk to the other adults for a moment. Why don't you get breakfast?"

Kesshi hesitated just for a moment. "Un," she agreed.

When Kesshi left, Naruto looked his wife over. The diamond-shaped seal on her forehead was a glaring variance from the day before. "Why do you have Tsunade's technique?" Naruto said, his voice strained.

"What?"

He lifted Sasuke's chokuto from the floor, allowing Sakura to appraise her reflection in the impeccable steel. "I don't understand…" she said musingly, lifting one of her fingers to her head, tracing the angles of the small marking.

Sakura's chakra felt different as well. It left a sense of uneasiness in the pit of his stomach. "We have to talk to the others," he said, walking towards the door Sasuke and Hinata had disappeared through. He heard Sakura follow.

When they entered, their two comrades were standing, Hinata gripping Sasuke's shirt, face buried in his chest, and Sasuke's arms wrapped around her. At hearing the movement, Hinata peeked up at them.

"Hanabi's keeping quiet," said Naruto, leaning the sword against the wall. "I convinced her you had PTSD. Well it's not entirely untrue."

"Hanabi's not one to complain," Sasuke muttered. "She's always been tough."

Naruto tried not to grimace at the remark.

"This is a shit show," said Sakura, leaning on the dresser.

That was an understatement. "What the hell did we alter?" said Naruto.

"A lot, apparently." Sasuke was holding his wife like a lifeline. He pointed a glare at Naruto, as though everything was his fault. Undoubtedly, it was time to engage in the blame game.

Naruto gave a frustrated grin. "I've been starting to notice that every night—we change. If we feel each other's chakra, and look at our bodies, the differences are subtle, but…" Naruto raised his hands to study them, at the intricacies of the scars there, in search of the ones that had long been his favorite. "Last night was the most substantial change we've seen thus far."

"Kesshi for Kasai," said Sasuke.

"The Genesis of Rebirth technique," Sakura murmured. She laid her hand on her chest, brows furrowed.

"The purpose of our offerings was to allow us access to the past and to make our adjustments irreversible," said Naruto. "There is no risk of a paradox. Our presence here is changing our young selves, and affecting us—and our world, in consequence. It means we are literally changing the future by the moment. And it means we're fully capable of saving it."

"Or destroying it," Sasuke spat.

"How do we fix our mistakes?" Hinata wanted to know, her voice muffled.

"By making more?" suggested Naruto.

"That doesn't m-make sense," Hinata protested, looking at him from the edge of Sasuke's chest. "It would be impossible to try to instigate Kasai's conception. We'd be more likely to end up with a different c-child," she broke off, her words breathless.

Naruto pressed his lips, trying to articulate his thoughts. "We…we all sacrificed something to be here. Assuming Kasai sacrificed as well, which she would have had to, right? We all had to…" He pretended not to notice Sakura's look of puzzlement. "I think her life is preserved somehow. Hear me out—none of us came to this time whole, or as we were. We each sacrificed something to exist here. We each reserve the right to exist, if only so the spirit can watch us struggle without my dreams, Sasuke's blood, your love for your sister," he gestured to Hinata. "If any of us cease to exist, our offering would cease to exist, and that would be detrimental to our benefactor. I think each of us have been written in destiny, even if the rest of the world is not."

"Fatalism and time travel don't exactly complement each other," Sasuke snarked.

"But it makes sense," Naruto argued. "Essentially, we can all die, but we cannot erase the fact that we ever existed." Naruto thought about his lost child, the details still taunting him when he made the mistake of running out of distractions—a son with blue-eyes and "silly pink hair." It had been described so engrossingly, he could almost picture the child. It made him a subscriber of Neji's doctrine; life was predetermined, at least to a certain extent. His son's life had been planned out before he had been born, probably before he had even been conceived. But he hadn't contributed anything in the negotiation. Unlike Kasai; Kasai was guaranteed.

"This all sounds t-too much like theory." Hinata finally pulled herself out of Sasuke's arms, and it was he who looked stricken and unsteady.

"Just tell us how to get Kasai back," Sasuke said tersely.

"I think your first child will always be Kasai, no matter when she is born," said Naruto. "I know we've messed a lot of things up, but we can still fix it. We just have to—nudge our counterparts back on the right trajectory." He tried to smile, but it was a pathetic effort. Because as assured as he was that they could orchestrate Kasai's inception, he wasn't sure what he could do for Sakura.

Sakura who was still pestering her heart with bits of healing chakra, a pensive look on her pallid face.

"Think on it," Naruto said to Sasuke and Hinata. And to Sakura, he said, "Let's talk." He took her hand, and guided her off.

Even at present, Inner Sakura was pulsing, beating in her mind, making her foggy, wanting to submerge, but it just wasn't the time for it.

Inner Sakura had the temerity to surpass her own reservations and judgements, her hesitations in battle, and her lifelong inhibitions to finally, truly, accomplish things. Even then, the pressure of it all made Sakura inclined the address the issue they had all be avoiding.

"Kesshi is innocent," she said cooly.

"I know," Naruto responded. He was seated on the veranda beside her, picking at his rice bowl. The metal chopsticks were always clumsy in his hands, as he tried to adjust to the weight and sleekness of the utensils on his calloused fingers. "But I can't—I can't think about that."

Sakura felt her jaw clench.

"Are you feeling okay?" said Naruto, not looking up from his rice. He sounded, sort of defeated.

"Fine," she huffed.

Kesshi was biologically her daughter. Hers, and Sasuke's. The child was indicative of a relationship between Sakura and the Uchiha, yet it would be akin to sleeping with her brother. It was Naruto she belonged with. This was an unadulterated fact that could not be compromised—she would never.

Yet Kesshi niggled at the back of her mind. The prim little healer. She and Kasai were mutually exclusive. One could exist, but not the other. My daughter.

Sakura stood. "I'm taking a walk."

"Sakura-chan…" But Naruto did not pursue her.

She walked along the roads mechanically, without having to pay much attention to her course, because the layout had not changed much in ten years. When she reached the bridge, it was vacant. She recalled the many hours she had spent here—she, Sasuke, and Naruto—waiting for Kakashi in their genin years. She leaned on the ledge and gazed into the crystalline water.

It was the eve of the attack, yet no one had even mentioned it. She supposed there had been a few distractions. Still, it was odd that such a notable occasion would not be addressed.

Sakura examined her reflection.

She had been feeling off since she had awoken to the commotion in the corridor with Hinata and Hanabi. She had not had the chance to take inventory of herself. But now, now she could feel that there was something distinctly wrong with her body, with the flow of her chakra, in fact, every facet of her anatomy.

Multiple personality disorder was a trauma disorder, meaning every time she was duly affected, her vicious alternate assumed control, doing as she pleased with the body they shared. Sakura knew it, though she was useless in fighting it. Yet she could distinguish them. She knew who she was.

She knew that she, Sakura, fought her battles until her knuckles were blackened, and face, blood-streaked. She knew that Inner Sakura would fight until she was suitably dead if someone didn't intervene.

But with the Genesis of Rebirth, she could get back up. She could not die in battle, and it unnerved Sakura more than it comforted her.

Casting a quiet dispel, Sakura allowed her body to relax and her chakra to recede into her core.

Her skin softened, veins bulging along her flesh. Her hair and lips paled, her eyes dimmed, and her body aged considerably. She did not look twenty-five anymore. She looked as her grandmother had days before she died.

Sakura continued to stare at her reflection.

So this was another thing that had changed.