A/N: I had another version of this story up under the same name, but I started much later in the timeline. I think this is a better way to begin the story, even if it is more conventional.

Chapter 1

I can remember a life before I was Karin of the Uzumaki clan. That fact has shaped my path in so many ways.

It is part of the reason I caught Orochimaru's eye in the first place and definitely why I kept his interest and, more importantly, his favor. Knowledge carried over from my last life, scientific ideas and methods in particular, allowed me to understand and contribute to the work in Orochimaru's labs almost from the moment I arrived.

Those years were good years, the best years. Before I learned about the truly awful experiments that went on in some of the labs, before I learned to make moral sacrifices for scientific progress, before I understood that my friends were dangerous men and women who could smile as they did terrible things and that this world was much crueler than the one I remembered. Before I met Sasuke.

I loved that place.

And sometimes, despite everything, I still do.

At twenty-four I died a stupid death. If I'd just stopped for a walk or a coffee or a nap or something I could have easily avoided the whole thing. Instead I fell asleep at the wheel. I don't know exactly what happened but it must have been quick because I never woke up again, at least not in that body. I can only hope that I ran into a tree and not another car, that my stupidity is not responsible for someone else's death.

I don't know why I retained my memories through the reincarnation process. I suppose it was a glitch of some sort, which is rather terrifying actually. It's a glimpse behind the fabric of the universe and, well, I really hope the cosmic powers that be are not fallible and that the multiverse is not falling apart. I try not to think about it too often.

What I can remember of the first few months of my new life is mostly associated feelings: hunger, helplessness, comfort, shame, confusion, rage, and wrongness. It wasn't until I was around four months old that my mind sharpened enough to put together the clues and I really understood what had happened to me.

I was a mess of negative emotions for a long time. I missed my family, my boyfriend, my cat, and just being a capable adult terribly. I was angry at myself and the universe for letting this happening. I felt ashamed that my carelessness, my failure, had led to my death (and possibly someone else's). I was horrified by how helpless I was, how weak and dependent I was on complete strangers.

The absolute boredom of being an infant certainly didn't help. I was helpless. I couldn't even sit up or roll over. The best I could do was flail a bit, grab things, then gum them to death. And I was nearsighted so I couldn't even people watch very well. Also I was dealing with a language barrier. I spoke English and a limited amount of Spanish, but my new family spoke Japanese exclusively. I recognized the honorifics and the occasional word like arigatō or ohayō.

(Odd thing: my clearly Japanese family seemed to dye their hair an unnatural bright scarlet. I wondered if that was a thing with us and whether I would be expected to as well. I'd always wanted red hair, so this I was okay with.)

However the boredom did have an upside: it led me to discover chakra and my chakra sense (because honestly I wouldn't have noticed it if I had had anything else to do). Chakra is life energy which permeates the living tissue of a body similarly to blood, except that chakra has no physical form. Most people never tap into their chakra and have to be trained to notice it. I was from another world, one without chakra, and I remembered 24 years in my old life well enough to pick up on the fact that there was something strange going on. Weirdly enough it wasn't in myself that I found the difference but in everyone else.

It started as feeling something alien emitting from people when they were near. It wasn't a tactile sensation or analog to any of the other senses. The best way I can say it is that I just knew that there was something strange about these people. This was only a couple weeks after I had remembered myself and I didn't trust my new family yet. The sensation was almost like hearing the buzzing of fluorescent light bulbs, once I felt it I couldn't stop feeling it and it drove me into a panic. For a while I howled whenever anyone who made me feel like that came near. Then I realized that that was everyone and that no matter how much I resented it, I still needed them. I was nervous and distrusting, but I knew I had no choice but to accept the feeling as a part of my life (at least until I was old enough to run away and live like a hermit).

Once I calmed down and actually started paying attention, I noticed variations in the feeling depending on who was near. It was strongest around my new mother and much weaker around non-family members. Though I was wary of the sense, I found it curious and I spent most of my time sort of poking and exploring the feeling. After a while I could identify the people I was around the most by alien sense alone. I learned to feel them coming from further away and to keep track of multiple people at once. Eventually, I could identify someone I knew before they came into my room. My range still wasn't very large and playing with the sense too much tired me quickly, but that was okay. If I was sleeping I wasn't bored.

Time passed. I (mostly) dealt with my issues from my past life , resigned myself to reliving childhood, and even grew excited about the possibilities. I could do anything with this life! And I was determined. I was going to make a difference and leave the world a better place when I was done.

Despite my growing chakra sense and a myriad of other clues, I still didn't realize I was in a completely different world.

We lived in a small farming village in the middle of a great plain of gently rolling hills and tall grass. The village was built on and between two low hills and the road into and out of town ran right through the center. The buildings were generally half built into the hillside and sod roofed. All the townsfolk had fenced gardens for fruits and vegetables, though my mother also grew plants for healing salves and potions. Some families lived as far as five miles outside of town, but were still considered part of our village. The population was just big enough to support my mother as a healer and my grandpa as a carpenter.

The level of technology in our village was incredibly low. There was no indoor plumbing and only the general store, the tavern, and my mother's workshop were connected to the electric generator. Traveling merchants who stopped by on their way to larger richer towns always had twentieth century gadgets to show off like walkmen or radios, but no one in the village owned such things. Far more useful to the villagers were the tools and cloth the merchants brought.

I think this would have been very upsetting and hard to get used to if I had been dropped in as a fully functioning adult, but as an infant, then young child I was too busy adjusting to the much larger issue of being a child to really care past some grumbling about having to use an outhouse. As I grew I was gradually introduced to the lifestyle. It became just the way we lived and, though I did have my moments of culture and technology shock, I adapted almost without realizing that I was adapting. When I thought about it at all I figured the one day I would leave for one of the cities and maybe bring back technological advancements to my small little town (or at least indoor plumbing).

All of this was confusing and rather contradictory to what I'd understood about the world. When I'd first recognized the language my family spoke as Japanese I'd made the completely reasonable assumption that I had been reborn in rural Japan, but the more I learned the less that assumption seemed to fit. Even the fact that we lived on a grassy plain seemed odd. I'd thought that Japan didn't have plains like this… Such thoughts worried me. I really didn't know what things were like outside of my village and I had no way of knowing how long I'd been dead or whether this was even the same world.

I was almost two years old when I saw proof that this world definitely wasn't my Earth, or at least that it was so altered that I couldn't reconcile it with the world I'd known.

I was in the kitchen, staying in eyesight of my mother while she went through her monthly cleaning spree (and Kaa-chan hated cleaning so I was being very well behaved). She was standing up and trying to reach a cobweb with the broom when she knocked a bucket of dirty water all over the floor. Then with a growl of frustration and several curses (which I did my best to memorize) she did something with her hands and I felt her alien aura reach out and warp into the water. Then water rose up in a twisty column and it all flowed back into the bucket.

I gaped. My mother could do magic! Could I also do magic? I could sense other people... wait, was that what I sensed in other people? Their magic? But that would mean that everyone could do magic. But then why hadn't I seen some sign of this earlier? Was the village a hidden society of magic users? Is that why my family had funny colored hair? (I'd learned that it was natural when mine began to grow in and that I also had weird red eyes. Like a creepy white rabbit. I was not pleased.)

Only one way to find out.

"Kaa-chan!" I gasped, "What was that?"

"What was what?" my mother asked looking a bit surprised and chagrined. I think she had forgotten I was in the room.

I toddled over. "You did something and... and the water moved! All on its own! Like, like..." I didn't know the word for magic.

"Karin, sweetie, I need you to keep what you just saw to yourself okay? Can you do that for your kaa-chan?"

"But what was it?"

"It was a simple water jutsu. Please Karin promise me."

"Why?"

"Because, and this is also a secret, I used to be a ninja. You know like in Grampa's stories? And if people find out bad men will come and take me away."

"Why?"

"Because the Hidden Villages try to keep all knowledge of chakra and chakra skills to themselves and their ninja. They don't like it if anyone else knows how to use chakra."

"Oh." I paused trying to absorb this new information. I'd always thought my grandpa was making things up in his stories to impress Kotetsu and me. The sheer impossibility of the things he talked about… but if magic was real… and regulated. "Can you teach me?"

"When you're older." She poked me on the nose, "Now please promise me you won't speak of this with anyone else."

"Promise."

After that I paid far more attention to the stories and fairy tales about ninja and samurai. Ninja were villains more often than they were heroes and there were several cautionary tales about innocent villagers who got caught up in ninja affairs. When I eavesdropped on adult discussions about politics I noticed that ninja were spoken of quietly, in dark angry tones, and with fearful furtive glances. I understood then that it might not matter that my mother had lived among and healed these people for years, we still couldn't trust them with her, our, secrets.

When I passed two years of age I was allowed to follow my older brother Kotetsu around and help out with his chores (more like watching me had been added onto his chores). Like many of the other children too young to apprentice in a trade or help out on the farm, he was responsible for watching the family's goats when they went to graze. The kids from the village would gather all the animals together on a different hill each morning then play games and reenact stories about ninja, bandits, pirates, and samurai. Being mentally quite a bit older, I frequently tired of the other kids and wandered off on my own. I think I developed a bit of a reputation as a loner among the other kids.

After I turned three and Kotetsu turned six, our mother began teaching us to read and more importantly to write. She was very strict about our calligraphy and we often had to practice the kanji long after our arms began to ache. It was particularly difficult for me with my three year old dexterity, but I managed. Only when Kaa-chan was satisfied with our work were we allowed to move onto the next character. It was a slow way to learn, but effective. (And I winced a little when I was included in these lessons because I'd been trying to mimic the other children and hide my advanced mental state behind a front of reticence and shyness. I obviously wasn't doing a very good job of it.)

When Kotetsu turned eight he began to work as Grampa's apprentice blacksmith. I was now solely in charge of the family's goats. My sensing ability (which I'd grown bored of playing with years ago) became useful again, for I found that I could use it to keep track of the goats the same way as I used to use it to keep track of people. My range was larger now and I could find missing goats very quickly. I learned to keep it running constantly in my subconscious as I paid attention to my books or played games with the other kids.

That year my mother and grandpa began teach us about our family and our birthright. Kotetsu because he was no longer considered a child and me because I'd already proved I could be trusted with secrets.

We were the last of a once powerful ninja clan, the Uzumaki. Our clan's home, Uzushiogakure, had been attacked by foreign ninja who feared and were jealous of our skill in fuinjutsu, or sealing. The family's ancient allies in the Senju clan of Konohagakure refused to provide aid and abandoned us. Most of our kin were slaughtered during the attack and the rest were hunted down and killed. For these reasons my brother and I were told to always keep our heritage secret, except from members of the clan.

We had lessons in the clan's sealing techniques every night in the secrecy of my mother's workshop. It became clear why our mother had been such a harsh task master during calligraphy lessons. Precision and deliberation are critical when drawing and designing seals. Even the best seal masters have to rely on careful brushwork (or chisel, needle, etc depending on medium) for a seal they have not made hundreds of times. Only someone who truly understands a seal can afford to be sloppy because their will and chakra compensate. A true master of a seal can place that particular seal with ink and chakra alone.

It was like learning another written language, an extremely finicky one. There are rules that determine the size of the symbols relative to each other, rules that determine their interaction, spacing and orientation, and rules for overlapping symbols. And of course there are sub seals and linked seals and arrays that allow you to link and layer seals and ways to open/expand seals for study and to reduce them back down again. And all of these methods and rules have their own exceptions and difficulties.

Kaa-chan drilled us on memorization every night for almost a year before we were allowed to create even the most basic warming seal. Then we had to learn to use our chakra to activate the seals and to disguise our seals in plain sight. As a part of this we learned about the ways different inks and paper and other mediums affect a seal. We were warned against placing seals on our own bodies until we had a far better idea what we were doing. Body seals are tricky and can interact in very strange ways with a person's natural chakra.

It is in the more complicated seal arrays that our clan's technique, the Uzumaki spiral, becomes most useful. The direction of the spiral and variations in line thickness can work to strengthen or weaken the relationships between parts of the seal increasing the power and versatility of Uzumaki seals. The spiral also allows us to adjust the size of the seal while we are working on it and cycle through different sealing layers, effectively making it possible to work and troubleshoot in 3 dimensions. With the spiral we can reduce the final seal down to a very small area regardless of its complexity. Finally the spiral can only be activated by Uzumaki chakra, so we can effectively lock our seals away from the eyes of most outsiders.

There are limits on what can be done with seals. In the most basic form seals link things or increase energy. It is in how these aspects are directed, combined, and inverted that give seals their versatility and complexity. This is often difficult, requires a thorough understanding of sealing, and needs quite a bit of (very careful) experimentation.

For instance a storage seal is basically a linking seal to a pocket dimension but the dimension must first be identified and defined. Then the link has to be directed to that specific dimension and the exit and entrance to the dimension have to be carefully controlled and defined. If a storage seal is done badly enough it is possible to be unable to retrieve stored items or even to be sucked into the dimension and suffocate. Which could make a potent offensive weapon. Conversely you could create a live capture seal if you include a linking array between the pocket dimension and the atmosphere around the seal.

Just after my eighth birthday (when I was formally declared to the village as my mother's healing apprentice), my mother and grandpa decided that Kotetsu and I had learned enough of the clan's fuinjutsu techniques to be considered adept. To gain actual skill and experience we would have to practice and develop our sealing skills on our own (with the caveat that the grownups were there to answer questions and look over any newly designed seals before we activated them).

"This is the point where we you would have been paired up with a master to teach further your sealing expertise and teach you other ninja skills." My mother explained a bit wistfully. "We can't afford to teach you much in the way of ninjutsu or taijutsu. We would have to practice outdoors and someone might see. I will however show you one of our clan's special techniques."

Glowing silver chains began to sprout out of her back and floated there like the wings of an angel. There were hundreds of the chains, each of them small and delicate, like silver jewelry. "The chains are unique to the Uzumaki clan because of our large chakra reserves and affinity for binding. Not every Uzumaki could manifest the chains and they are different for each person."

My grandpa grinned a bit ruefully, "Mine aren't as flashy as Unami's, but I was a bit of a brawler back in the day and they were awfully useful in loading my punches or extending my reach." He scrunched up his face in concentration and a chain slid out of the back of each of his hands and wrapped around his knuckles. The links were the color of steel and approximately the size of his thumb.

"That is so cool!" My eleven year old brother gushed. "Jiichan teach me! Pleeeeease!"

I contributed my best puppy dog eyes to the effort.

Kaa-chan laughed before continuing, "You both will need to greatly increase your chakra reserves and control, but hopefully it will give you something to work towards. Remember to only practice in secret."

Many of my early dreams for fame and fortune had fallen by the wayside when I realized how different this world was from my last and how limited my resources were as the daughter of a healer in a tiny village far from the capital. It was okay though. I was kept busy between lessons and chores and my role as Kaa-chan's apprentice and I found sealing and chakra fascinating. I had a warm family that I loved and though I was considered a bit strange by many of the villagers, I wasn't a target for bullies or harsh comments. Life was simple, but good. Unfortunately that did not last.

It was a few months after Kotetsu and I "graduated" from fuinjutsu lessons and lately I'd been finding the other village kids more annoying and my mother's restrictions more onerous than usual. Kotetsu, my usual conspirator, had once again decided that he was too old to play with his "brat of a little sister" and ditched me for some of the older boys. So in an irritable mood, I escaped to spend some time on my own.

There was a small creek about a quarter of a mile outside the village. Everyone knew about the creek of course, but I headed further up the creek bed until I could no longer hear the children playing in the water and the women gossiping as they washed their clothes. There I found my favorite place: a big smooth boulder propped against a great oak tree.

It was early summer, so water still tricked through the creek bed and a warm, light breeze rustled the leaves in the tree. The sky was clear and blue with the occasional white fluffy cloud. Perched on the bolder, leaning against the tree was the perfect place to watch the sky and just relax. I idly stretched out my chakra sense to warn me if anyone planned to come bother me.

About an hour later, just as I was thinking about heading home for dinner, I felt a number of unfamiliar ninja sized chakra signatures enter my range from the northern road. We didn't get many ninja out here, but the occasionally a team stopped for lunch or to stay a night at the tavern, so I didn't think much of it even though there were an unusually large number of presences, maybe as many as six or seven. They split up when they reached the town and where they went the villager's chakra started disappearing.

I sat up startled. That had never happened before. I could still sense the strange presences, so it wasn't my sense fritzing out. Confused, I focused all my attention on the village wondering what could cause that (except…maybe…I shied away from that horrible thought).

There went the innkeeper and the old man who never remembered my name and my sort of friend Izami and our neighbor Suki and her husband and their baby… and… And I felt my mother's chakra flash furiously, surging and warping along with two then three of the foreign presences. Then suddenly she was gone. Her presence winked out.

I shut it down.

All the way down. I pulled my chakra sense (and all the rest of my chakra with it) as far into myself as I could, clutching my knees to my chest and making my body as small as possible, refusing to believe that what I feared might be happening. Was happening.

And I hated myself for being too much of a coward reach out and check again. Too much of a coward to go home and see for myself. See if I could help.

"And," I told myself over and over, "if you would only go look you would see that everyone is fine and you just overstressed your chakra or had a nightmare or... something."

I stayed like that for hours, long past when I should have been home. No one came looking for me.

I don't want to dwell on what I found when I finally dared to return home, but sometimes I can't avoid it. I still have nightmares of that day. Of entering town in the predawn light, cold and worried for my family, but also about the trouble I was sure to be in having stayed out all night. Not noticing the unnatural stillness of the town at first, then realizing that the farmers should be leaving for their fields now. Nothing. No movement other than the breeze sweeping off of the grassy plain. A door opens and slams shut. Then again, flapping in the wind.

It is then that I see the first body. She is fallen sideways in her garden behind her house, head turned away from me, limbs splayed and twisted unnaturally. I don't recognize her at first, then I do. It is Anita, the butcher's wife. She was a nosey and suspicious woman, but also the best baker in the village. On feast days she would give every child in the village a small moon cake. She didn't deserve this. Shock and fear hold me paralyzed while I stare at her, then slowly, carefully, I release my chakra sense from the miniscule ball I'd tucked it into last night and reach out for my family, for anyone. I find nothing. No one. Just rats, and chickens, and goats.

Slowly I walk towards my home in the center of town. Now that I have seen one body I begin seeing the others. I try not to look, but I can't help it. I am in shock and I feel tears begin to run down my face, but it doesn't feel like it is me crying. Everything all feels so unreal and distant, like a video game I played in my last life.

The only house that is damaged is my own. The street in front of my house is torn up. There are great gouges cut out of the dirt road and towering spikes and walls of dirt beside them. Some have fallen down from gravity and others look as though they have been partially washed away by high pressure water. Several long thin spikes shoot out from the front wall of my house. They look hard and deadly sharp, but a cluster are broken and missing their points. Beneath them is a red haired body. A woman.

My mother.

She is laying crumpled and face down in the dirt, the missing tips of the spikes jutting haphazardly from her back. A dead body I don't know is in my way, neck twisted at an odd angle and the imprint of chains across his throat. I hardly notice it on my way to my mother.

She is cold and stiff when I try to roll her over and I immediately stop. I sit down on the ground and touch her hair and cry. I don't know exactly how long I stay there, but the sun is high in the sky by the time I go look for my brother and grandpa. I don't have to go very far.

They are both in Jiichan's woodshop and there are signs of a battle here as well. From the way their bodies are positioned it is obvious that our grandpa died defending Kotetsu and there is another dead stranger, this one with large chain imprints on his broken head. I stare at their bodies silently for a long while before I drag Kotetsu and Jiichan closer together. I gather up all the wood in the shop and stack it around and over them and around and over Kaa-chan. Around the makeshift pyres I stuff dry hay and smaller pieces of wood. I want to bring Kaa-chan here as well to be with them, but she is much too large and heavy for my nine year old body to carry and I don't want to drag her through the mud.

In my mother's office I find the sealing supplies hidden in the usual spot. I sit down and make fire seals. I make fire seals all day until I run out of ink and paper, at least a couple hundred of them. I am extremely low on chakra by the time I am finished, but I have enough left for what I need to do. I set a fire seal on every body I find and every building. I let the chickens and goats and other animals out of their pens.

I collect a few things from our house and seal them away into a scroll. Sentimental things like my mother's necklace, the tiny wooden dragon Jiichan carved for me when I was four, Kotetsu's favorite book "The Tale of a Gutsy Ninja," the precious photograph of the four of us together, trying so hard and failing to be solemn for the camera man. Some practical things too: all the money I can find, my mother's healing kit, my grandpa's carving tools, some food and clothes, a tent and a canteen. I remember what I'll need from my first life, although I've never been camping or even left the village in this one.

The sun is setting by the time I finish. I stand on the hill above the village and use my chakra to activate the control seal in my hand. The village goes up in flames. I watch it burn long into the night.

A/N: The more I thought about her and what we know of her life and skills the more Karin screamed to be a self insert. My SI comes from a world without Naruto, so she has no clue what she is in for, just the skills, knowledge, and experience from being a twenty-something mechanical engineer.

This story will likely finish at the end or near the end of the Chunin Exams. There will be OC's since there aren't many named Grass-nin or Oto scientists/assistants. I eventually plan for a three part story: pre-timeskip, timeskip through Sasuke's murder of Orochimaru/forming Hebi, and the conclusion.

I do not promise strict canon compliance, but I will do my best to make sense of and interpret the canon world in a believable fashion. If I get something obviously, glaringly wrong please let me know and I will try to fix it if it doesn't wreck the story, or I will try to work in an explanation of why things are the way they are.

P.s. I figure that hiding intelligence and maturity from an attentive parent would be nearly impossible. SI Karin is clearly bored and ready to learn, so there is no reason for her not to be included in her brother's lessons. If Karin couldn't hack it, her mother would have just tried again in a few years. In my head, cannon Karin started her various lessons when she was at the ages Kotetsu started lessons. She would have seen the chakra chains demonstration, but would have only been a couple months into fuinjutsu lessons when her village was slaughtered. Not enough time to know more than the very basics and to keep her mouth shut about her heritage.

P.p.s. I own nothing.