Hey everyone, silverfox56 here! This is my first ever fanfiction. And when I mean first, I really mean first. This idea came to me when I was watching the movies. I hope you all like it. This is just a prologue to the actual story. One reason I did this is to see how many people are interested in reading my story. If not many people do, then I'm not going to continue. Another reason is to introduce the main character, the eyes that the story is told through. Without further ado, onto the story!

This is my story. A side to one story that you have never heard before. You have all heard of the famous Teenage Mutant Ninja Turtles. The ones that save the city and the world from threats like the Kraang and Shredder. But you've never heard of one of their greatest secrets. The secret that they want to keep hidden from everyone, especially their most hated enemy.

And that secret would be me. Their little sister. I haven't been part of their family long, only 2 years, and like an outcast. They try to include me in everything that they do, except going to the surface. They never let me leave the sewer. And I don't feel like leaving. This is the first real home that I have had. The hole I lived in for most of my life doesn't count. Now I bet you're wondering how I came to be. It's sort of a long story, so I'll try to narrow it down.

Everyone at TCRI was curious about how the mutagen affected the turtles and wanted to learn more. So they decided to see if they could make another one. Somehow they got their hands on a lot of mutagen. And when I say a lot, I mean a lot. When I was locked up, I saw an entire room full of it.

They bred many Red-Eared Sliders and when they were infants, splashed mutagen on them. I was the first successful mutant that didn't have any side-effects. I can only imagine the horrors that came upon the ones that weren't so lucky.

I was under lock and key for 5 years. They studied me in every aspect they could think of. My cell production, digestion, brain waves. They hooked me up to machines, starved me to see how long I could go without eating. They did the same thing with water. And many more horrors that I would prefer not to mention. Until, one day, I got fed up with how I was treated. I broke out, causing a mass panic as I escaped, and hid in the sewers. That's where I stayed, for three years, hiding from the world that apparently didn't want me. During that time, I sort of trained myself how to hide. I had to hide from people that, for some reason, came to the sewers. And just in case the people from TCRI came looking from me. I taught myself how to walk without making a sound. How to sneak around the sewers without being detected, especially in the water. I can step without making a splash. And can creep among the pipes in the ceiling without making one creak.

I found the TMNT about a year and a half after I freed myself. At first, I was terrified of them. Then I realized that they were just like me. I became fascinated with them, how they moved, how skilled they were with their weapons. And how much of a bond they had with each other. So I followed them whenever I could. I eventually found their lair but, didn't go much further than that. I did that for the years leading up till they saw me for the first time.

I was sleeping in my hole when I heard it. The creak of pipes giving out. I couldn't get out of my home before the ceiling came crashing down on me. When I woke up after who knows how long, I tried to free myself, but when I shifted, I felt fire shoot up my ankle. I looked down. It wasn't at an odd angle, so that means it wasn't broken. Which means it's sprained. I tried to get it unstuck, but it hurt every time I moved so I had no choice but to lay there.

They found me a couple days later. At least that's what they think it was based on Don's analysis. I was dehydrated, malnourished, and on the brink of death. I recovered pretty fast, faster than I thought I would. I didn't know why, and I didn't care. I was just happy I wasn't dead.

When I finally met Don's health seal of approval, they tried to ask me questions about where I came from. How I ended up stuck under 300 pounds of solid rock, and anything and everything that came to their heads. But I didn't answer. I learned how to talk by listening to the scientists who were around me 24/7. I never talked to them thought. What was the point? I had nothing to say to , I didn't really trust them. Sure they saved me, but I couldn't be 100% sure that they did it out of kindness or they wanted something out of me.

So that's how it was for the next week. Them asking a lot of questions, and me not answering. Me trying to find every possible hiding spot that I was sure they would never find me in. Every time I thought I found one, Mikey, which I guessed at the time was the youngest and the most immature, would show up. I eventually found one, high up in the wall, that looked like it had never been touched. And I was right. Every time I thought Mikey would show up, he didn't.

After a month, it was safe to say I was part of the family. I was treated like one of them, and as a living thing, not like a successful experiment. This was also the time that they decided to see if I had the potential for ninjutsu. Leo brought me into the dojo, where Master Splinter and the rest of my "brothers" were kneeling, all facing me. Leo sat me down and went and stood next to Master Splinter.

I'm pretty sure they saw the confused look on my face, because Splinter said, "Do not worry, my child, you are not in trouble. We have all come to a decision about how to progress further. Leonardo will explain." This scared me even more. How to progress further? Were they finally going to kick me out? I studied their faces. None of them had any look or any physical sign that that's what Splinter was referring to. I looked back at Leo. He had a soft expression on his face, so I knew nothing bad was going to happen.

"As you know, young one, you have been with us for about a month. We treat you as a sister and would like to continue to have you as part of our family. Do you agree?" I stared at them and thought for a little. I finally have a family. One that treated me good. And they could protect me from my previous captures if they ever come for me again. So I nodded.

"Good. Then here comes the tricky part. We have to come up with a name for you." That part I didn't expect. A name? I've never had a name. Why would I need one? I always expected that they would keep calling me "young one" and "little sis". Master Splinter interjects. "I might have a solution for this problem." He grabs a book out of his robe. All four of my brothers like this book means something to them.

"Is that..." Mikey trails off. "It is my son," Splinter responds. "It is the book that I found the names for all four of you. And since it brought such luck to us before, it might bring us luck once again."

He waved me over and I sit next to him. He opens the book and flips to the female section. "When you see a name that you like, point it out, and we will go from there." He slowly turns the pages, giving me time to study every name, what it means, and what that woman did. He continued to flip, and I continued to read, but I couldn't find one that I liked. He finally stopped. "This is the last page, young one. I hope you can find a name on this one."

He turned it over and I looked. It was the last woman on the page. She was tucked away in the corner, so little writing next to her picture you might have skipped over it. But I didn't. She wasn't the most beautiful woman, but I loved her name. I stuck my finger at her picture and Splinter leaned over to look at it. He smiled. "I like that name. It suits you."

Everyone else leaned over to look at the page. After they read it, everyone agreed. Except for Raph. He didn't say anything, and knowing him, it probably meant he didn't like it and was expecting more of a badass name. I'm pretty sure he didn't say a word because he didn't want to spoil the moment for me. I finally had a name. And identity. I was jumping up and down inside, but on the outside, I didn't show any emotion. What was the point? They already knew I liked it.

"Catharina it is," commented Leo. He smiled. "Now that we have that dealt with," began Splinter, "We had one other thought." He looked down at me. "Would you like to learn ninjutsu?" Out of all the questions they've asked me before, this one took me the most by surprise. My mouth fell open, but I snapped it shut. I would have to think about this one. So I shrugged. "We'll give you some time to think about it, of course," Donnie butted in. "you have to let us know soon so we can start. You are a far ways behind the rest of us." So I nodded.

I sat there thinking about it, so deep in my thoughts, I didn't notice any of them leave the dojo. Soon I was the only one there, sitting in the middle of the room, staring at the floor. Do I want to learn? It would be cool to learn. And I would be able to protect myself if the TCRI guys ever came after me. But could I ever live up to the rest of them? They've been doing this much longer than I have and have way more experience. Would I ever be as good as them?

I must have sat there for hours because when I got out, the place was quiet. Must be that everyone already went to bed. I walked over to the couch, where my makeshift bed was. It was mine until they could find another hole in the sewer that wasn't being used. Donnie offered to move his lab, but I shook my head. He loved that place. It was his private little area. I wouldn't take that away from him. I laid down on it and pulled the covers up to my chin and fell asleep straight away.

A week passed before I agreed to start training. Turns out, I was a natural. Even more than Mikey. I mastered everything physical they had learned in 16 years within a week. Then Splinter let me spar with them. I'm pretty sure Leo was jealous when I beat him within the first minute.

After that, we started with the weapons. I mastered those in two weeks. I surpassed them in that field as well. Now for this, I'm sure Raph was pissed. I could see the anger in his eyes. He didn't act on it though. That made me happy.

Now that you know most of my backstory, I can finally move on.

Hope you enjoyed the prologue! Let me know if you're interested in reading more. I'm in school, so I'm not setting a schedule for when the next upload will be, but check every week just in case. I might upload every couple days or not for weeks at a time. But bare with me, I'll try to upload as soon as I can. Like I said before, if I don't get enough interest then I'm not going to continue. Have a great day.

P.S. constructive criticism is always welcomed. And the title right now is temporary. I can't think of a good one right now. If you have any suggestions, let me know. If I change the title, I'll let you know what it is a chapter in advance.

I'm also going to say this now so I don't have to ever say it again. I don't own TMNT. It belongs to the rightful owners.