Author's Note: It's looking like 41 chapters, which would include one more interlude and two epilogues.
The Chaos Theory
by Bullwinkle's Lady
Mirai Naruto stood in a forest clearing surrounded by the lush trees of the fire country, their leaves so dark, they were almost blue. They swayed in the warm breeze, dripping water like ink from the drooping foliage. The water, in turn, was a crystalline blue when it touched the sunlight that poured down through the shadows. Naruto bowed his head under the dawn. He was far enough from the village that no one was likely to bother him. He had completed his seals but had yet to activate the jutsu. He drew a kunai from his weapons holster and shoved it into his abdomen.
"Nrrgh..." Naruto grunted, pushing the weapon deeply enough that he wouldn't be able to heal. Blood dripped with soft, even taps, against the fallen leaves, alongside the raindrops, mingling, but never fusing with the water. His blood was far too impure.
Mirai Naruto stumbled forward several steps, but collapsed to the ground before he could reach his destination, a broad oak tree, against which he would perch – against which he would have held Sakura when he brought her back with him from that realm of death.
Naruto rolled painfully onto his back. It would have to do. He stared into the sky, at the brightness of the sun, and slowly, it consumed him.
Suddenly he was in that realm again, where wonderful and terrible things transpired. He lifted his eyelids. The pain was gone. He wondered if this was what death was like. Mayhem, manipulation, emptiness, greed...
He heard a near-forgotten voice, and forced himself to climb to his feet. Ero-sennin. And as he said it, it seemed the sannin materialized before him. Mirai Naruto fell into the larger man's arms. Tears ran down his cheeks, his emotions overcoming him. I was trying to reach you before. Or baa-chan. Not him!
Jiraiya said nothing, and Naruto slowly looked up from his kimono, meeting his tattooed face and arrogant grin. Naruto couldn't help but smile back. For just that moment, he thought everything would be all right.
What do you want? His sensei said.
His words were marked with apathy. Despite his beam, his face was devoid of recognition. His grin softened to a more sinister smile, eyes alight with something Naruto couldn't comprehend.
Naruto swallowed, and started. "I want-" he halted, grunting in pain as his organs twisted within him. It was like his entire being was at war with him. "I want Sakura back," he said hoarsely, and dropped to kneeling, clutching his abdomen where the pain was at its apex. "What can I offer?"
Words echoed around him, within him, and was accompanied by more pain. Naruto held his skull which felt as though it was splitting in two.
I want your beating heart.
...your past and future...
...you to be separated from her for eternity.
But Jiraiya spoke simply, Give me your soul...
And I'll see what I can do...
Naruto stared. You'll see what you can do? The sannin was offering him no guarantee. That isn't enough, Naruto urged, but Jiraiya simply watched him. Naruto's eyes turned red. Give her to me! he snarled. He lunged for the elder man, but his body met air, and he collapsed in a heap to the grass. Gasping, Naruto looked up at the sky. He was back in the Fire Country, his clothes soaked in blood. Releasing a strangled cry, he wrenched the kunai out of his stomach, and then he lay there in the grass, shaking...
Sakura further away from him than she had ever been before...
Mirai Sasuke sharply inhaled from the pain of her contact. Sakura usually handled his injuries. He met his wife's torn expression.
"You need to be healed. I'll get Tsunade-sama-" Mirai Hinata turned to leave, but he caught her arm.
Both looked at each other with stubborn expressions. Hinata recovered the bandages and continued to meticulously wrap his torso. Not too loose, not too tight... like all the times when she bandaged Hanabi's eyes, she mused. Her eyes drifted to Sasuke's arms. Those too were covered in cuts and burns.
"I'm fine," said Mirai Sasuke. He seemed more fatigued than anything else. His eyelids began to lower.
There was a knock on the door, and a blonde head poked into the room. Mirai Naruto offered a guilty smile. "Hey."
Hinata immediately moved in front of Sasuke, her palms out and byakugan activated. She glared angrily at Naruto.
Naruto frowned as he entered. Hinata had failed to realize that Sasuke had been the main aggressor in their conflict.
"It's okay," said Mirai Sasuke, but Hinata did not take her eyes off the blonde. Sasuke stood with effort, and rested his hand on her shoulder. Hinata looked up at him and reluctantly lowered her stance.
Sasuke nodded to Naruto.
"Where's Kasai?" Mirai Naruto asked casually.
"Entertaining some elders."
"I'm sure..." Naruto snickered. "Heh." He seemed very weary. Finally, he answered Sasuke's unspoken inquiry. "It didn't work." He glanced away and scratched his head in hopes to disguise his frustration.
What did they want? Sasuke asked.
Che. My soul.
Sasuke clenched his jaw. The stakes were getting higher. He had feared as much. He recalled Sakura's unwilling offering. At that kind of price, how are any of us going to be able to get back to our time?
"I don't care!" snapped Naruto, aloud.
Sasuke scowled, and Hinata's eyes widened as she realized she was being excluded from the conversation. She looked at Sasuke, her brows furrowed.
Naruto's eyes were focused on the window. He distractedly wiped at his tears.
He remembered all the times in the past Sakura had almost died. But she was always okay. She always survived. Her biggest regret throughout her adulthood had been not acquiring Tsunade's seal. She had been determined she could protect everyone alongside herself.
"We can get her back, Naruto-kun," Hinata said quietly. "Like Kasai-"
Naruto shook his head. "It's different. Sakura hasn't ceased to exist, she died naturally. I can't unteach her the seal-"
"You can teach her not to abuse it," said Sasuke.
Mirai Naruto bit the inside of his cheek. Sakura was stubborn at any age. He had no confidence that he could restrain her with words alone. Not with all the dangers she would find herself encountering in the coming years. Not with Inner Sakura persistent, and pressuring her to take action.
"I can eliminate the reasons she would find to use it in the first place," Naruto finally said. "Hanabi-"
"Hanani isn't a threat anymore," Sasuke disagreed, but Naruto wasn't convinced. "Sakura would find reason to abuse the seal regardless. You have to start from the beginning."
Naruto grimaced. "Inner Sakura?" He was reluctant about Sasuke's convictions.
"Even before that."
That morning the young Sasuke went to the young Naruto's apartment. He himself didn't know specifically what for. He needed someone to confide in, but at the same time, didn't want to. It was all giving him a headache. After several seconds of rapping on Naruto's door, Sasuke turned the knob and found it was unlocked.
Naruto's studio apartment was no different than it had been during Sasuke's previous encounters with it: a mess. The floor was covered with garbage, dirty laundry, and other miscellaneous effects, the walls slathered with an assortment of condiments. There was no one in Naruto's bed, but a tan foot was poking out from a pile of rumpled newspapers. Though both had their own apartments from a young age, they couldn't have kept them more differently.
"Dobe?" called Sasuke casually. He opened the fridge and poked around through the barrage of moldy food. He wrinkled his nose at some furry mayonnaise before noticing a shivering toad in the corner by some slimy cucumbers.
The toad cried out in happiness at his apparent liberation. Sasuke took it. Sniffed it. The toad's seemed uncertain towards the Uchiha's behavior. Then Sasuke opened his mouth, fully intending to stuff the creature inside.
"Gama-chan!" Naruto screeched, snatching the toad and roughly shoving Sasuke aside where his head collided with the freezer door. "Leave him alone, you snake bastard!"
Sasuke stumbled away from the fridge, his nose bleeding from the impact. He eyed the blonde. Naruto was dressed in heart-printed boxers and a wifebeater. Sasuke hadn't noticed before, but Naruto was more muscled than him now. Like Kiba, even. He wondered if Hinata liked brawny guys.
Petting the toad protectively, Naruto returned it to the safety of his refrigerator, cutting off the creature's protests as he slammed the door closed. "What are you doing here anyway?" Naruto grumbled irritably. He reached into his boxers and scratched his ass.
Sasuke scowled and wiped his nose on arm warmer. "Just stopping by."
"Ne, teme?" The blonde was suspicious. "You're not trying to murder me again?"
Sasuke shook his head. "I told you, I'm just dropping by. After all, you are my..." he struggled to produce his next word. "...friend."
Naruto stared at him in a mixture of fear and awe.
"Anyway I have something to tell you..."
But the blonde was backing away, his eyes darting about wildly. Sasuke noticed he was moving in the direction of the window.
"You're not in love with me or something-?"
"And you're not trying to kill me?"
Sasuke tried to reason with him, but as he approached, he slipped on a pair of moldy underwear. He crashed into Naruto, and the two collapsed in a heap on some aged pasta.
"Never mind," managed Sasuke. Rotten spaghetti was his limit.
The two climbed off each other, both rather peeved. Sasuke noticed a mission hawk fly through window and perch itself upon Naruto's head. As the blonde hastily unraveled the note, Sasuke decided to make his leave. He had somewhere he had to go anyway.
"Ne teme, you're on here too."
Sasuke paused halfway to the door. He glanced back at Naruto.
"They want us at the gates immediately."
Naruto and Sasuke arrived at the gates within the hour, where they met Sakura, who seemed just as confused as they were. Their orders had been urgent, yet no one was present to meet them.
Sasuke was suspicious. As he was sealed to the village, it didn't make sense that he would be included in a mission...unless Tsunade was intending to lift her seal? It didn't seem plausible, but the concept left him keen. He touched his chest, where it was burned into his skin.
The three members of team seven turned and paled at who they spotted.
"Oh no..." groaned Sakura.
Mirai Naruto wore a wicked grin. He had dark circles under his eyes and looked especially deranged that afternoon.
"I'll be handling your training today," he said sinisterly.
So it had been a trick. There was no mission. Sasuke glared at the young Naruto, who shrugged. It wasn't his fault his future-self was a crazed lunatic. He gave his teammates a strange wink. I'll take care of this loser.
"What's this all about," young Naruto balked. "Look, we have things to do. We have no time to play with you. Freakshow." Folding his arms behind his head, the young Naruto walked off, his sandals slapping loudly on the dirt path.
Sasuke and Sakura sighed and began to follow, when Mirai Naruto suddenly materialized before them. Before any of them could act, Mirai Naruto kicked the young Naruto in the chest and sent him flying through the village gates, where he crashed to the ground.
Out of instinct, Sakura went after Naruto, but with a sharp cuff to the abdomen from Mirai Naruto, she collapsed. Before the young Sasuke could prepare himself, he was at the receiving end of Mirai Naruto's assault as well.
Mirai Naruto was faster than any of them could have imagined. He attacked them one at a time, never giving any of them a chance to regain their footing or collect their composure. He alternated between slamming Sasuke's head into his knee, to stomping upon the fallen Naruto's ribs, cuffing Sakura thrice in the throat, then back to knocking Sasuke around. The teenagers were easily outmatched by the future nin.
Mirai Naruto knew the three fought best when united. He thwarted any efforts they made to regroup. Maybe that would have been a challenge. Mirai Naruto smirked at the floundering teenagers. They could barely gauge where he was going to be next.
A collection of bashes, bruises, and fractured limbs, Sasuke was the first to collapse. In contrast, the young Naruto always got back up. He had the greatest stamina of the three. He was durable to the point of detriment. Mirai Naruto struck him repetitively across the face, each of his cuffs erecting splatters of blood. He caught his young self by the throat and squeezed tightly. "No hard feelings," he grinned.
He had gone easier on Sakura, who was sprawled on the grass. He couldn't hit her with the enthusiasm with which he hit the boys. Mirai Naruto watched her from the corner of his eye. She forced herself up to all fours, trembling from the effort of staying conscious. She lifted her face and stared hatefully at him, her eyes alight with an infuriation only Inner Sakura could generate. The diamond on her forehead suddenly glowed.
So Sasuke had been right.
Mirai Naruto abruptly dropped the young Naruto and reappeared before the young Sakura, who jumped slightly in surprise. He knelt down to her level, lifting his pointer finger disapprovingly. "Bad idea."
"...what?" Sakura was too dizzy to understand. She watched his hand curl, and then everything went black.
She woke up in bed wondering why her whole body was aching. Sakura groaned and sat up.
She looked up to spot Mirai Naruto sitting on her window sill, and she abruptly remembered the day's events. "Where are Naruto and Sasuke?"
"They'll be fine."
"Why did you-?" Sakura fumed. "You're insane!"
"Maybe I am?" Mirai Naruto smiled to himself, seeming amused by her remark.
She hadn't thought Naruto could be any more offensive than he already was, but in the past couple of days, Mirai Naruto had proven her wrong. He had gone from insulting her and her friends to outright beating them up. To that moment Sakura could not comprehend how such an asshole could have such an attractive smile.
"I wanted to talk to you about your inner-self."
Sakura's eyes widened. "How do you know-?"
"I'm from the future." Mirai Naruto waved her off, silencing her impatiently. "She's bad for you, you know? She'll be the death of you."
Sakura drew up her knees and wrapped her arms around them. She didn't know how to control Inner Sakura. She didn't know why it mattered. It was just a defense mechanism. It wasn't as though it was anything serious. So she voiced her wonder, "Why does it matter?"
Mirai Naruto dropped from the window sill. He approached her and took her hand, examining her pretty, bruised fingers. "It's the only thing that matters," he said.
Sakura was at a loss for words.
But just as quickly, Mirai Naruto released her hand and returned to her window. He lifted one of his feet to the frame, before pausing. "Don't worry about my young self. Surprising as it may seem, he's pretty competent with his fists."
And still, she didn't understand.
"He can take care of himself," said Mirai Naruto, looking back at her.
Sakura was stricken. Her fingers gripped her sheets. When had Naruto ever taken care of himself? It was always her! Didn't Mirai Naruto know? Hadn't he been there all those times? Didn't he see himself die and awake, time and again, in her arms? Or was he just as oblivious as his young alternate?
"Naruto-" she said, looking up. But he was already gone.
The young Sasuke sat on the teacher's desk of the empty classroom he had visited on several occasions over the past month. He was ridden in cuts and bruises, his shirt torn, and his face covered in scratches. His arm was in a sling, and there was a bandage taped to his cheek. His posture was terrible, and he seemed generally irritable, so much so that Hinata was reluctant to inquire-
"Are you okay?" Her words were mumbled. She pressed her pointer fingers together, gaze averted from his.
"Fine," said Sasuke, fumbling and throwing off the sling. He began to straighten his arm, before wincing, and deciding against it.
Hinata stared at him and wondered who had beaten him up.
"It wasn't Naruto," he said abruptly, before pausing and realizing that wasn't entirely true.
"I-I didn't think-!" Hinata stammered, also lying. They looked at each other, then looked away, falling into silence.
The purpose of their meeting was to discuss the recent events – their marriage, Kasai's conception date – how they would go about the next five or so years – but both realized they didn't particularly want to talk about any of it. They had come to realize they were different from their past selves. They hadn't been forced to mature at the same pace.
Hinata lowered her hands to force herself to stop fidgeting. Maybe if she tried to open up then he would too. She swallowed her nerves and started. "I'm going to take the jounin exams when I turn eighteen. I was thinking of taking on students." Something Mirai Sasuke had mentioned made sense. He might have known her better than she knew herself.
"You can't keep them when you get pregnant," Sasuke said dismissively.
Hinata flushed. It was a logical point. "Then m-maybe after I have-" His. Their. "-th-the baby."
"With our child at home by herself?" said Sasuke scathingly. It seemed he had strong opinions about parenthood. "Not to mention our other children."
"W-what other children?"
"Reviving a clan is a lot of-" He should have said work, but what he said was, "-sex." He looked her over, seeming strangely content.
The room was spinning. "M-maybe we can have t-t-two." Hinata was willing to compromise.
Sasuke did not look pleased.
"A-and you can help l-look after-"
"I'll be in the ANBU, I won't have time for babysitting," said Sasuke flatly. "Besides, I'm not a fan of children. I think you should consider retiring-"
"I don't want to have any children with you," Hinata abruptly decided. She turned to leave, but Sasuke stood, catching her wrists.
"I'm teasing you."
She wasn't convinced. The room continued to swim around her.
"Two then," said Sasuke. He pulled her until their bodies were touching. She felt heat rise to her cheeks, but refused to meet his eyes.
Sasuke sighed and released her. He pulled a slip of paper out of his pocket. The one Mirai Hinata had given them. He crumpled it into a tiny ball and tossed it into the overflowing wastebasket.
She couldn't remember the date. Did he remember the date? She hurried to the wastebasket and dropped to her knees to rummage through the hundreds of billions of tiny pieces of scrap paper packed into it. She felt desperate, mortified, and was dimly aware of how oddly Sasuke was staring at her. But the date was important! She hadn't realized just how important until that moment!
"I remember it," Sasuke reluctantly reassured her. He seemed fascinated by her panic.
Hinata looked up at him from the floor, teary-eyed. "How could you be sure?" It was Kasai's date of conception – a critically important date. What if they messed everything up? She balled up her hands and held them to her eyes, proceeding to hyperventilate.
"It's my birthday." Sasuke's voice cut through the chaos.
Blinking, Hinata lowered her hands from her wet face. "What?"
"Kasai was conceived on my twentieth birthday," he deadpanned. Even he wore a slight blush.
Both stared at each other for a moment, and then abruptly looked away. Her face was burning.
There was nothing more to be said.