It was dark and his entire body felt paralyzed. There was a dull pain in his neck, and he could feel the scratching and scraping of pine needles against the skin of his bare arms. It felt as if the air around his body was trying to drive him into the ground.

Then, a warm hand landed firmly on his shoulder and someone was calling his name.

His body remained still and uncooperative.

The voice sounded once more.

Kakashi, wake up it coaxed.

His eyes began to flicker open, letting the voice drag him into consciousness. The light of day was harsh on his still adjusting eyes; the Tomoe in his left eye spun to life lazily as he awoke. The bleary figure of a man in black came into view. Itachi? He thought. No, wait...

Kakashi's eyes shot open completely as he regained his faculties. The man's chakra was so strong that it was almost overpowering. Out of instinct, Kakashi sat up, cast his hand backwards, and unsheathed his tanto, instantly bringing the blade to the kneeling stranger's neck. The man didn't even flinch.

"I'm not an enemy," the stranger said evenly, daring to look directly into Kakashi's eyes, seemingly unphased by his Sharingan.

Kakashi studied the man carefully, still holding the tanto to his neck. He had pale skin and black, shoulder-length hair that hid the left part of his face. The man's black cloak concealed the upper half of his body, but Kakashi had spotted the standard shinobi pants and the end of a scabbard peeking out underneath. He wore no hitai-ate.

"What village do you belong to?" Kakashi croaked, his voice hoarse from disuse.

"The Hidden Leaf," the stranger said simply, expression blank.

Kakashi's gaze sharpened as he scanned the man's features once again. If the man was a leaf shinobi, Kakashi had never seen him before. Once again, he noted the shinobi's visible eye and found that it looked almost familiar. Almost like the young shinobi on his ANBU squad…

Then the man closed his eye and, when it opened again, three spiraling tomoe and a red iris not unlike Kakashi's own had emerged, confirming what Kakashi had already begun to suspect.

"You're an Uchiha." he said as he loosened his grip on the tanto slightly.

"Why have I never seen you in the village before?" he probed, hesitant to let go of the weapon completely.

Kakashi was conflicted. The sharingan couldn't have been stolen since the man could activate it at will. However, he had never seen this Uchiha before. The lack of a hitai-ate led him to believe the man was a missing-nin. The problem was that there hadn't been any reports of a rogue Uchiha since Madara and the clan was meticulous in their record keeping. Although unlikely, he supposed it was possible that the man could be a bastard born outside the village.

The nameless Uchiha hadn't attacked him while he was unconscious, which probably meant that the man was telling the truth about being a Leaf Shinobi. And, if the man was to be believed, Kakashi wondered how he hadn't heard of him before. He couldn't rule out the possibility that this man could be an enemy. His inner deliberations were cut short when the shinobi began to speak.

"I've been away from the village for a while. A long-term mission of sorts," he explained. His expression remained neutral but his eyes flitted over the stray dirt Kakashi's ANBU uniform before landing back on the silver-haired shinobi's face.

"How did you end up here?" The Uchiha asked as his eyebrows drew together. For the first time, Kakashi noted, the man's features had shifted from the blank, indifferent stare. The genuine concern in the man's eyes was not lost on him.

Although he couldn't allow his guard to lower completely, he re-sheathed his tanto, deciding he was not in any immediate danger. He thought back. An image made its way to the forefront of his mind. A man with flaming red hair and a vengeful, lilac gaze, and then a searing pain in his neck. He tried to grasp at the thought, to dig deeper into the memory, but came up with nothing. He knew he couldn't trust this Uchiha completely, but he had no clue as to where he was, nor the events leading up to his collapse. He would give the man some of the information, but he would keep the details to himself until he could report to the Hokage.

"I… don't know. There was an enemy, but that's all I remember," he said, as his hand unconsciously drifted to the humming spot on his neck. The Uchiha did not miss the action.

"You're hurt," he said as he eyed Kakashi's neck.

He cursed himself for giving away more information than he intended.

"It's nothing," Kakashi dismissed. "I'll live."

The Uchiha looked uncertain for a moment but eventually decided to drop it.

"I don't sense any foreign chakra nearby. We should get you back to the village where you can be examined. It will be a two-day journey if we stop to rest for the night," The Uchiha stated and pushed up off his knee to stand. He held out a hand to the still sitting man.

Kakashi hesitated, but ultimately accepted the offered hand. He concluded that he would have no choice but to follow this man and trust him for the time being. Regardless, It would probably be best to keep an eye on the mysterious Uchiha.

"So, what am I supposed to call you? Since you already seem to know my name," he inquired, rising to his feet.

There was a long pause before the man responded,

"Just call me Uchiha, for now."

The sun had just barely met the horizon as the two shinobi sped through the forest, neither making a sound. The air had become crisper and the light that once crept through the canopy of trees had vanished.

As they approached a clearing near the riverbank, Sasuke was the first to speak.

"We should stop here for the night and pick up again at dawn." He announced as he slowed to a stop.

Kakashi said nothing but followed his lead, setting up camp in a hidden area of the clearing.

While silently observing him, Sasuke realized the predicament he was in. He hadn't really had time to take in this younger version of Kakashi and the reality of it all was starting to hit him full force.

Deciding he needed a moment to himself, he turned to leave, informing Kakashi that he would collect some kindling for a fire.

Sasuke ventured deeper into the forest, pausing occasionally to gather dry branches and twigs.

His former sensei, who had been in his thirties just a year ago, didn't look a day over twenty. He had the Sharingan. The Sharingan. And he seemed to have no idea who Sasuke was.

Sasuke knew that space-time Ninjutsu was possible. After all, he had the Rinnegan. But this?

He thought over the possibilities. If this younger version of his sensei was from the past, did that mean that the older version was running around somewhere in the village? If the timeline was linear, it would create some sort of temporal paradox and, if that were the case, he doubted this dimension would have remained intact for as long as it had. So, he ruled out the prospect.

That brought him to his next plausible theory: Dimension travel. It was possible that young-Kakashi was not from this world at all. He wouldn't be able to verify it. He knew next to nothing about his sensei's past and wouldn't notice the differences between the two.

But that didn't explain the strange wound on Kakashi's neck.

Kakashi's neck was still concealed by his clothing, but during their initial encounter, Sasuke had noticed the strange pulse of chakra in that spot with his active Sharingan. That couldn't be a coincidence.

It also didn't explain why the area around Kakashi had seemed so... wrong. There had been untamed vines and dense forest where a path should have been. The overgrown patch of forest had seemed to span a diameter of about ten meters with Kakashi lying dead center.

He wondered whether the other man had noticed and had simply not trusted him enough to say anything.

In any event, this was not something he could figure out by himself. There were too many variables to consider.

I resigned; he sighed and circled back to the clearing, kindling in hand.

As he approached, he spotted the younger version of his sensei. The shinobi was sitting cross-legged on his bedroll, staring at his right hand. That was something he had never seen his sensei do.

As their eyes met, Sasuke's steps almost faltered at the unfamiliar sight. The usual bored aura he had come to associate with his sensei was gone. The empty look in his lone, black eye was a jarring sight. Gone was the lazy slouch of his back and the disinterested gaze of those half-lidded eyes. He was all sharp edges and hard lines. Not for the first time, Sasuke wondered what the man had been through in his past.

He tore his eyes away and placed the kindling in the space between their bedrolls. He slipped out of his black cloak, exposing the empty sleeve swaying at his side. Crouching down on his knee, he began to perform the one-handed seals for a simple fire style jutsu. He felt Kakashi's eyes on him as he blew a steady stream of fire onto the wood.

"Something wrong?" Sasuke asked, staring into the flames once a decently sized fire was burning. It was not the first time someone had stared at his missing arm.

There was a pause as Kakashi seemed to ponder his next words.

"How long have you been away from the village, Uchiha-san?"

That was not what he had expected.

Sasuke had to be careful. He didn't want Kakashi to know everything yet, especially when he didn't know the details himself. As soon as they got back to the village, the man would surely find out, but if he tried to explain it all right now, without any evidence, Kakashi would never believe him. He decided that half-truths were better than lying completely.

"I left around seven years ago. The details are classified," he said as he turned to face the Copy-nin, hoping the man wouldn't question it any further.

Kakashi seemed to consider him for a long moment, suspicion lurking in his eyes. To Sasuke's relief, the man seemed to accept his answer and nodded once, shifting his gaze to the fire. Whether Kakashi truly believed him or was just playing along with his story, Sasuke had no idea.

He decided to use Kakashi's question as an opening to continue the conversation. Sasuke was not a sociable person by any means, but he knew he needed to squeeze some information out of this frustratingly stoic Kakashi, even if that meant stepping out of his comfort zone and maintaining a dialogue.

"How's your neck?" he asked, keeping a casual tone.

"The pain has subsided," Kakashi said, not sparing him a glance.

"Do you remember anything? How you ended up unconcious?"

"No," Kakashi replied dismissively.

This was turning out to be more difficult than Sasuke had imagined.

"I'm just trying to get to the bottom of this. It won't help if you try to hide information from me."

"How can you expect me to trust you? For all I know, you could have been lying from the start. How do I know you're not the one who caused this entire situation?" Kakashi snapped.

"If I were, do you think I'd willingly accompany you to the village?" Sasuke responded coolly.

Kakashi was silent for a while before speaking again.

"I apologise, Uchiha-san, but you must see things from my perspective..." he trailed off.

It's fine; however, you can't blame me for being a little curious as to why the famed Kakashi of the Sharingan was lying incapacitated in the middle of the forest.

Kakashi let out a humorless chuckle.

"I was never worthy of that name," he muttered, looking down at his hand.

The fire crackled in the space between them.

"Can I ask you a question?" Kakashi requested suddenly, in an obvious attempt to shift the focus off of him.

"Hn."

"What happened to your arm?"

Sasuke's lips twitched; it was evident to him that this Kakashi was not as practiced in the art of elusion as his former sensei.

"A friend beat some sense into me," he said, sending Kakashi a knowing smirk.

"A friend? What kind of friend would do that?" Kakashi asked, refusing to meet Sasuke's perceptive eyes.

"A really, really good one," Sasuke replied, expression growing distant.

"Sometimes the most important lessons are the most painful to learn."

Sasuke let the silence linger between them and into the darkening night.

As they settled down for the evening, Sasuke found himself stealing glances at his former sensei. He was so much less confident than the man he had known. Now, he could see the similarities between himself and this young Kakashi.

His eyes often found the injured spot on the young shinobi's neck. He had never seen anything like it before.

For the first time in a long time, Sasuke was worried.

Kakashi had always been a sort of mentor to him – one of the bonds that tied him to the village. The relationship may have been strained, but Sasuke knew that, underneath it all, they truly cared for one another. And he had always looked underneath the underneath.

Now that the man's life was possibly in danger, he feared that he would never get the chance to earn his forgiveness. He had never wanted or needed to rely on Konoha's aid in the past, but he found himself hoping the village would know how to fix this mess.

That night, Kakashi took the first watch. He spent most of the time wracking his brain for answers. How had he ended up in the middle of the forest? He had thought that memories of the previous day would come back eventually, but that had turned out to be wishful thinking.

He remembered going back to the village after a mission with Team Ro. It was just a standard assassination. He remembered walking home from the ANBU base and stepping into his apartment. Then, there was a flash of red and purple, followed by blinding pain, and then...nothing.

He had also spent an excessive amount of time thinking about his enigmatic travelling companion after their conversation.

When he had caught the man staring at him in a way that was almost fond, it had caught him off guard. It wasn't a look one would give a stranger. But the man had supposedly been away from the village for years, and Kakashi had never even seen him before.

The more time he had spent observing the stranger, the more he had been reminded of Itachi. It wasn't just his looks, but also his mannerisms. Even their voices sounded similar. He had begun to wonder if they were closely related.

By morning, he was exhausted; he had gotten no sleep. He couldn't allow himself to be defenseless around a potential enemy.

Now, he hoped, as they proceeded to the village, his mind would be put at ease and his questions would be answered.

The Uchiha had seemed to grow more and more tense throughout their journey, further aggravating Kakashi's suspicions of the man.

As the village gates appeared in the distance, the two slowed to a walking pace.

"There's something you should know," the Uchiha stated as he stopped walking, just minutes away from the entrance.

Kakashi stopped a few steps ahead of the man and turned to face him, eyeing him warily. If the shinobi turned out to be an enemy of the Leaf, Kakashi wondered what he could possibly hoped to achieve right outside the village gates. What was he planning?

Kakashi continued to stare at the Uchiha in anticipation, preparing himself for whatever the man was about to do. The Uchiha seemed to choose his words very carefully, but didn't seem ready to attack.

"My name," he said finally, meeting Kakashi's gaze, "is Sasuke Uchiha."

There was a long, drawn out pause as the two stared at each other.

"There's only one Sasuke Uchiha," Kakashi said eventually, unsure of what the man was trying to say, his suspicion growing even more.

The Uchiha broke eye contact for a second, a hint of frustration marring his features before they were schooled back into their calm façade. He turned back to Kakashi as he said,

"We are the same person."

"Last time I checked you weren't a four-year-old," Kakashi responded dryly.

"Of course, I'm not—" the Uchiha seemed to grow even more agitated. "The last time I saw you, one year ago, you were thirty-two. But right now you look…"

"Nineteen. I'm nineteen. What are you saying exactly?" Kakashi interupted, getting impatient. His hand hovered dangerously close his blade.

Another long silence.

"I think you travelled through time," The Uchiha winced at his own words.

Kakashi tried to understand what the man was saying to him. This guy is delusional, he thought, shaking his head and dropping his eyes to the floor. Either that or he's the worst spy ever. He wanted to laugh at the absurdity of the claim.

"Do you really expect me to believe that?"

His eyes found the man claiming to be Sasuke Uchiha once again, and his amusement vanished immediately. Instead, he found only unwavering resolve in the Uchiha's gaze.

"I can prove it." The Uchiha said, by way of an answer.

Kakashi relaxed his stance slightly and considered the man's words again, more carefully. It wasn't possible. Was it? He recalled his earlier thoughts about Itachi and how the Uchiha was so similar to him. It would explain why Kakashi hadn't met him before (or was it 'yet'?). He brought two fingers to the bridge of his nose. He couldn't believe he was actually entertaining this man's ludicrous machinations.

The Uchiha seemed to sense his inner conflict and stalked closer to the village gates, motioning for Kakashi to do the same.

"Come see for yourself," he said as he stared into the opening.

Kakashi walked over to him, still on his guard, and followed the Uchiha's gaze.

Then, he froze. He opened his Sharingan. It was not a genjutsu. He stood, mouth slightly agape as he counted not four, but five Great Stone Faces on the Hokage mountain.

Before he could even begin to process the information and calm his rapidly increasing heart rate, there was a massive, fiery chakra heading their way. It was just as powerful as the Uchiha's, if not more.

A blond man appeared in the distance, barreling towards them at a break-neck speed.

As soon as he saw the blue eyes, he knew. If the man next to him really was a fully-grown Sasuke Uchiha, then that meant…

"Bastard!" Naruto cried, a huge grin on his face as he slammed straight into Sasuke. He draped a tanned arm around Sasuke's shoulder, almost causing them both to lose their balance.

"You're kind of late, you know?" the blonde remarked as he regarded the strained look on Sasuke's face.

And then the cerulean eyes, the eyes that had always reminded him so much of his sensei, fell upon him. Naruto's eyes widened, eyebrows rising to his hairline. He poked an accusing finger at Kakashi's chest as he asked, bewildered,

"Oi, Sasuke, what the hell happened to Kakashi-sensei?"

A/N: Thanks for reading. What do you think of Sasuke in this chapter? Constructive criticism is always appreciated. Review and favourite for more!

This fic is also available on Ao3 if you prefer. Updates will probably be posted there first.