It couldn't be. It made no sense!

Gazing into the microscope's eye piece, a part of me was fascinated but another part of me was starting to feel scared. This is the part of my brain that is always saying things like 'SAFETY FIRST' and 'SLOW DOWN, YOU MUST BE CAREFUL'! That little voice is annoying and sometimes very bossy. Right now the things it was saying were making me a feel sick to my stomach.

I'd put together this slide myself. I'd been excited and did it kind of quickly. I hadn't used gloves. I hadn't been careful at all collecting the sample! It had not occurred to me that the mysterious substance might be dangerous, but… maybe it was. I looked back towards my bed. I could no longer ignore the possibility. This was not ordinary. The proof was right before my eyes, though it was hard to believe.

There was something alive in that stuff!

What I want to know is, if I'm so smart, why do I have no idea what to make of these strange results? Splinter calls me a marvel and says my brain is a 'precious gift'. He says a lot of corny things when he feels proud of me. But there are still so many things I don't understand and even more things I can't do. Sometimes I worry that the day will come when I've been wrong too many times – or maybe just wrong about one really big, important thing - and then Splinter will see that he was wrong about me.

These aren't rational worries. I know that. But knowing only makes it worse when the thoughts won't go away. The trick is not to get worked up in the first place. The best thing to do is to get my mind busy right away figuring out a solvable part of the problem. If it's nothing I can solve, I'll work on something else completely so my brain has something to analyze other than myself.

Splinter says it's okay to be wrong. He says it happens to everyone, even people who have grown very old and wise – but especially it happens to people who are young. He says not to worry, because I am wrong a lot less often than most children. He says this is because I am not only smart, but also very mature for my age. That's something I can definitely believe. For as long as I can remember, I've been obsessed with grown up things and my head is always filled with grown-up ideas.

I am only eleven years old, but I think it should be noted that (assuming no one has been playing tricks with the clocks again to buy more free time before training) in forty-two days and almost nine hours I will be twelve.

Okay, maybe not really. We don't know for sure, because our real ages can't be determined. We just celebrate the day Master Splinter found us like it's our birthday, and who knows how long we were waiting around in that pet store before some kid bought us and dropped us all down a sewer drain? But by my family's standards I'll be twelve. That's official enough for me.

Being twelve will be a lot better than being eleven. Twelve is almost thirteen, which is pretty old. And thirteen will be downright awesome, because it means I'll be an official teenager.

I bet if I were thirteen I could figure this out in like two seconds.

I gave myself a shake. No giving up! Testing has only just begun. Newly determined, I leaned forward and looked again. There it was, same as before. I couldn't help staring, even though I'd observed these results sixteen times already. It was just SO NOT what I had been expecting.

There was something very wrong with what I was seeing. But these single-cell creatures were intriguing, too. Oh, man. It might be a Huge Discovery!

It was clear that I did not have enough data, and if I wanted to get more I must respect the unknown factors. I vowed to proceed cautiously from now on. I still did not know how the goo even got there, so that seemed like as good a place as any to start. I had made a guess about it – which, if you're doing science, you get to call a 'working assumption' or a 'theory'. I figured it must have come from my body somehow. It's kind of embarrassing, but I had been wondering if maybe I… um… peed it out.

There's a more scientific way to say that, I am sure of it. I'm going to look it up before I talk to anyone about this so I don't have to blush when I say it. (I hate blushing. Someday I will cure blushing.)

The point is, the sample was discovered in that area. This is why I was not so excited about reporting my findings to my brothers and Master Splinter, like I would have normally after making a Huge Discovery.

Peering into the microscope for the seventeenth time now, I was no longer sure about my current working assumption for the goo's origins. For all I knew, aliens put it there. Observing the weird movement taking place on the slide, I was also no longer sure I should even be referring to the goo as a sample. If it was alive, the proper word was probably specimen. It was kind of a spooky thought.

If it did come from my body, that was kind of scary to think about too. Could they be… parasites? A bad feeling started to swell up inside my chest at the thought, and I shoved it back down with annoyance. There was no reason to be a scaredy-cat just yet. There was not enough supporting evidence.

I considered my previous observations when I had examined my own skin under the microscope, or bits of scute that came off my shell, or my blood, or one of Splinter's hairs, or other samples that had come from living, breathing things. When I viewed those findings they did not move. Not like this. None of them ever moved anything like this. I pulled away and sat back in my chair, staring at the microscope for several more minutes, processing everything.

My eye caught on a spiral-bound notebook lying open to a blank page on the desk beside me. Normally I write in notebooks like this several times a day, but that does NOT make it a diary. Anybody who says it is a diary will get smacked with my bo, and trust me, it will hurt.

Diaries are for writing about bad days and girls on TV you might have crushes on and things you secretly hate about your brothers. Diaries are stupid, and that's not even my opinion. I can prove as a FACT just how stupid they are. Because diaries have a very good chance of getting found by your little brothers. Diaries give your brothers all kinds of new reasons to tease you, and diaries give little brothers reasons to be upset by the parts that were about them. I have proven all this with the Scientific Method, using hypothesis that I drew from Leo's unfortunate experiences with trying to have one. So, seriously. Just say NO to diaries.

This notebook that I write in every day is actually my current Log of Failed and Successful Experiments. It is much better than a diary because it contains only important records and observations related to my research. Nothing written on its pages will ever hurt anyone.

One of the best talks I ever had with my sensei was the one where he explained to me that my failed experiments were more important than my successful ones. Even though successful experiments make me feel happy and let me know that I am doing well as a scientist, it is really more from the failed ones that I become a better scientist. If there is one Great Truth that I have come to believe in, it is that the most interesting things about the world and the way it works often can't be grasped until you've worked through enough of the related ways that it DOESN'T. I'm not saying I never get frustrated when the things I am trying aren't going well, because of course I do. It's just that there are many successes that never could have existed if not for the failed ones that came before it.

When my head is filled with angry thoughts, I try to stop and look at it this way. It usually brings my soul peace.

The Log of Failed and Successful Experiments is one-hundred percent safe to write in. Apparently each of my brothers have tried to read it at least once, if not several times. By this point they have come to the unanimous agreement that it is very boring. That's fine with me if they think it's boring. Truthfully, there are parts that I find boring. What they don't understand is that science usually needs its boring parts to do great and amazing things.

I realized that I still had not written anything down in the Log of Failed and Successful Experiments about this morning's amazing new findings. Normally I do this right away. I should have been doing it all along. Each time I looked into the eyepiece, I should have been writing down any new things I had observed based on what I saw in the circular, microscopic view of the slide.

I picked up my pen and began to scribble my thoughts down onto the page. "June 14th. Upon viewing the new sample," Whups, that was a mistake. I had to scratch that out and write: "specimen under a microscope on the highest settings, the tiny things–" I paused and scribbled out the last two words. They did not sound very grown up. I replaced them with: "microscopic organisms seem to be moving around like they are swimming. The movement I am seeing is not slow like they were just floating around due to being in a liquid environment. They are swimming around LIKE CRAZY!"

I stopped myself before I could add a third exclamation point, frowning at the words that had spilled out of my pen in my excitement. 'Like crazy' was not a very scientific description for their movement, for one thing. I was going to put zig-zagging instead, but that was a kid's word and not any better. Frenzied? Frantic, maybe? I didn't like either of these adjectives. The first one made the organisms sound mad, and the second sounded scared. That would be what grown up scientists call a fallacy because I had no reason to suspect that it was any specific emotion making the specimens move around so fast. I doubted they were advanced enough to have feelings at all.

Suddenly it came to me. Erratic. It was the perfect grown-up word to use.

LIKE CRAZY was not a very bad error, I decided. Certainly not bad enough to require re-writing the whole page, It would be good enough just to elaborate, which is the grown up word for explaining things better. "Their swimming is very fast and erratic," I read the words aloud as I wrote them, pleased with the mature and accurate ring to them.

I looked back over what I'd written before that and realized that I also needed to be careful with the exclamation points. I couldn't help remembering what my big brother had said about them the other day when we were finishing up this one writing assignment for Master Splinter. Leo and I finished first, of course - him a little bit before me, but both of us way before the others. He asked me if I wanted to exchange papers so we could check for each other's spelling errors and stuff. I agreed. It couldn't hurt to check, but I did not really expect my paper to have errors. Leo's paper was very good too, with no spelling errors, but I did correct his verb tense in two paragraphs and point out a word that didn't mean what he seemed to think it meant.

Leo only found two things that were bad about my paper. I didn't say so out loud, because it was too stupid to be worth maybe getting into a fight about it… but I don't really think either of them should have counted as errors. They were his opinions. The first one was he felt I should write the whole thing over because the hand-writing was so bad, and he said so in a big note –- more of a mini-paragraph really – which took up the whole top margin of my page. He even quoted back parts from my essay where he'd had to guess what a word even meant just by the sentence it was in, and went over several other reasons why he felt good penmanship was very important.

Of course I just rolled my eyes and wanted to blow him off completely. My paper was a work of BIOLOGY, not fine calligraphy. Except now, of course I HAD to rewrite it unless I wanted to hand it in to Splinter with Leo's stupid essay about the honor and glory of good handwriting on there. I was very annoyed that he used a red pen. I had used pencil on his, and even those marks were very light. I was almost as annoyed by the pen as I was by how every one of his bright red letters seemed to gleam on the page, each one so very beautiful and perfect looking. Of course it had the effect of making MY letters look even more like crap than usual.

His second correction was much simpler. He had just drawn a circle around a place where I'd used some exclamation points and suggested in the margin, "Just use one." I questioned him about it, making sure he knew that I really did mean it to sound loud. Leo insisted that putting too many exclamation points in what you were writing was stupid because it made it look like a baby wrote it. I asked him, but then what if the monkey's vocalizations ARE really loud? Louder than other things you'd say with just one exclamation point? Leo said to use caps, and I said I DID also use caps, and then he said he didn't KNOW but it was just WRONG!

We were glaring at each other. Then Mike rushed to my defense, I guess – or maybe he just saw an opportunity to show off and be the center of attention. He declared that he didn't care what Leo said, because he loved exclamation points. He said they were the best and most noble of punctuation marks. They were wonderful, and just to celebrate how wonderful, he started re-writing his whole final draft so there was exclamation points after every single sentence. You could tell it just bugged the CRAP out of Leo, even though he pretended to ignore it. He loudly resumed telling me his opinions about multiple exclamation points and how wrong they were, and the only reason he was saying so was for my own good, because nothing I wrote would ever be taken seriously by scientists if I kept doing that.

I was actually starting to take what he was saying seriously, but I didn't want to admit it to his face at that point. I asked why he was so worried about me? Apparently Raphie thought ALL punctuation was stupid, considering how little of it he used in HIS papers. I waved a hand towards where he was plastron down on the ground, chewing on his eraser and scowling at his page, the only one of us still working on his essay. His paper was a mess because he was working on the floor, which was neither the cleanest nor the flattest surface for doing a writing lesson.

Leo peered down and agreed that this was very true. And it was pretty much the reason he refused to check Raphie's work, because if he tried there would be so much red on the page no one could read it. By the way, did Raphie know his pencil had gone through the paper there and there? Raph batted at his hand and gave him a look like he would rather have bitten it. He growled that at least his wasn't going to be BORING, and scooted his paper in closer so people would stop looking at it. And yes, he felt it WAS pretty stupid to care about periods and crap because Splinter would still know what he meant.

In the end Splinter DID give it back and told him to fix it… specifically for the bad punctuation. Too bad for Raphie, but pretty funny for us. Less funny for Mike when he got his back too. Hah!

Well, in this case it was not a writing assignment for Splinter. It was just my log of failed and successful experiments. It was ok to be excited about what I was saying. I decided that two exclamation points should be okay. In the weird situation that Leo or any real scientists asked to read my findings, it would just take a minute to re-write it.

There was another reason to be cautious, and it had nothing to do with threats to my health. I couldn't help wondering if the specimen might be linked to the strange way my tail had been behaving in the mornings lately. When it first started happening, I began a log recording the day's date and the time it occurred, how long it took for my tail to go back to normal, etc. There was even a column to note the length of – well, I didn't know what to call it, so the heading above this category just said 'cm. of growth'.

After awhile I stopped recording unless I noted changes, because for the most part it had begun to make that strange transformation EVERY morning, and recording the same thing over and over each morning was starting to get pretty boring.

I was careful not to handle it any more than necessary when my taking measurements. Early on I'd discovered a definite trend in my findings: touching it always made it take longer for the growth to go back in my tail where it – well, crap. I sure hoped it belonged there. Perhaps I was being optimistic in my working assumption that it was how my tail was supposed to be, and not some – I don't know, freakish tumor or a baby alien that was like, nesting there, and – RRRGH!

You see what I mean when I say I was making myself sick? The above is a perfect example.

This morning – the morning of the goo – it had not come out of my tail at all. This would have been odd, even without the goo. I didn't want to think that it might be relevant to the goo, but as a scientist it was a possibility I could not ignore. One thing I have learned about being an honorable scientist is that we must never look away from the facts that present themselves just because they do not match the facts we want to see.

A couple weeks ago I learned a new word that I liked very much, and it was correlation. Mike even caught me using it twice in the same day and started making jokes like, was it the Word of the Day? Could he play? Because he wanted tomorrow's Word of the Day to be DORK. I told him that word was no good because it was too tiny and easy to be a Word of the Day. And Mike said I was right, he knew a dork who was definitely tiny and easy, and that's when Leo came over to yell at him.

Leo said some things to Mike like what he'd said was VERY bad, and I don't think Mike meant the words in the way Leo must have thought he meant them, because he started to look very confused. To be honest I was confused too, and very curious. Later on I asked Leo about what he thought Mike had meant. He widened his eyes and said "Donnie! He was saying your you know what was tiny!" When it was clear that no, I did not in fact know what, he gave me a smug little smirk like I was a total baby. He declared that the conversation was over in that case. I'd wanted to punch him in the face, just for a second, but I let him walk away.

"Huh. That was weird," Mike commented, and he looked at me like he was hoping I would agree with him.

I didn't answer him in time and eventually Mike left the room muttering under his breath. I could think of nothing to say to stop him, plus it seemed like more effort than it was worth. Instead of watching him go, I kept staring in the direction Leo had gone. I was beginning to understand what 'you know what' meant.

That was the moment I realized that my brother Leonardo knew more about this scary stuff than I did. I realized he was making insinuations about our tails – about our tail's recent growth, in particular! It was a Huge Revelation.

And now I was having another one.

I shook my vision free of the memories and my wide eyes fell on the barely filled page from today's Log of Failed and Successful Experiments. Reliving the conversation from two weeks ago had filled me with inspiration. I grabbed my pen and wrote down the new idea about the specimen, before I could get too carried away analyzing it.

"WHAT IF THIS IS NORMAL? Perhaps this specimen is something my brothers already experience – or have YET to experience? DEFINITELY WARRANTS INVESTIGATION." I underlined the last three words for emphasis.

I would investigate soon, but not just yet. First it seemed important to give the chore of technical documentation a genuine effort. So I went back to the microscope and wrote down every stupid boring-but-important observation about specimen that occurred to me. I estimated their approximate length (about 50 micrometers) and how far they could swim in an hour (not very, in spite of their apparent fastness, being so small…a couple cm per hour at most). When I had filled up most of the page with figures I decided it was enough and used the opposite page to sketch them out dutifully.

The sketches in my Log of Failed and Successful Experiments are nothing like Mikey's creative doodles and many attempts to draw comic books. They are serious technical drawings. I try to use as little imagination as possible and only draw exactly what I see like you would see, and I always use sepia (okay fine it's a brown colored pencil) in homage to the drawings I had seen from the sketchbooks of famous naturalists.

As always, attempting to draw what I was supposed to be observing helped me gain new insight. It forced me to focus hard on just ONE of the wriggling worm creatures ( a term which I immediately regret, and vow never to use again in favor of "single-cell organism"). It struck me all at once that the swimming of the specimens was not erratic after all! Each one was swimming in a very straight line. My first impression, that the organisms were swimming in a crazy zig-zagging pattern, was actually an optical illusion created by the way they all would swim in different directions.

I turned the page and was just about to start writing down some initial theories when a knock at the door startled me out of my skin. I slammed the experiment log closed as fast as I could and panicked for a moment about hiding the specimen. A moment later I felt stupid for worrying. Nobody would think it was suspicious if I just turned the microscope off and left it where it was. It would be camouflaged by all the organized chaos that Master Splinter insists is lazy clutter.

"Who is it? I mean, come in!"

Leonardo poked his head in and gave me a questioning look as he announced, "It's Leo."

"Obviously. Uh. Hi, Leo," I greeted him with less than perfect confidence. It was really hard not to glance at the microscope. In the back of my head I had been going over some of the notes I was going to write next, but the sight of my big brother frowning from around my bedroom door reminded me of the proposed investigation of my siblings. "So, um. What do you want?" I blurted like an idiot.

Leonardo didn't give me an answer right away. He just stood there, looking at me like I had lost my marbles. This time I couldn't help it, and peeked back at the microscope and over at the bed sheets. Finally my questing gaze honed in on the clock on the wall.

"Oh!" I realized. "It's almost time for training."

"You've got no time left for breakfast. Splinter wants you dressed and standing before him in the dojo in three minutes. You know I hate that he makes me do this, don't you? I shouldn't have to be a living alarm clock for you slackers."

I bit my lip and felt truly sorry for him. "Of course you shouldn't."

Leonardo did not appear to want my sympathy. He scowled and left the room.

All through training he was really tough on me. I didn't get to do any covert investigating whatsoever because I had to put so much attention on surviving our sparring matches.

When I was finally free of him, I raced back to my room and locked the door behind me. I ran to the microscope and almost knocked it over in my haste to peer into the eye-piece.

There was no reason left to hurry. I sat up slowly from the microscope and glanced at the clock. Then I flipped open my log and picked up the number two pencil. With mixed emotions, I wrote: " June 14th, 13:41 - Experimentation cannot continue. The specimens have died."