It's been a rough couple of weeks.

First, we had the showdown with the Shredder, on a spaceship hurtling through the stars, no less. He and Karai were headed to conquer the Utrom homeworld, when we stowed away to stop that from happening. Even though everything ended relatively well, we came pretty close to losing not only the battle, but our lives. I know we face that possibility every time we draw our weapons - have been trained to know it since we took our first steps - but to actually look death in the face like that...to know that in a few short moments, your entire family was going to die a violent death alongside you...definitely not something I'll forget anytime soon.

Then we lost our eldest brother. Okay, so that's a bit melodramatic, since physically he's still here with us (don't get me wrong, obviously I'm grateful about that). But mentally, emotionally, he's became an entirely different person. The old Leo (the calm and collected big brother/leader we all love and follow) never returned from that battle, and in his place we have this dark and angry stranger with a permanent scowl. He hardly speaks to us, not even Master Splinter. I haven't seen him meditate in almost a month. He doesn't eat much and when we're not training or patrolling, he hardly ever leaves his room. Not even Raph at his worst has ever been this bad. If arguments between Leo and Raph were volatile before, these days they go positively nuclear. My next project might be a fallout shelter.

Leo did sustain a serious injury during that almost-final battle, which is bound to be strain on him. But I think there's more to it than that. His anger is like a scab over some deeper, inner hurt, and it's grown so pervasive that I have no idea where to start. I'm an engineer, not a psychologist (though I did complete that free online course not too long ago).

And now...well.

Looking back, I guess it kind of all started when Bishop entered the picture. He's proven himself to be a more than formidable enemy, and his interest in genetics (specifically ours) and access to all sorts of advanced methods and equipment was a bit of a wake-up call. It got me thinking: our mutations were extremely isolated and complex events. what if Bishop could undo them? How in the world could we ever fix that?

I had to find a way to answer that. I had to get my hands on some of Bishop's technology, so that I could develop new backup plans, new fail-safes - things we couldn't afford not to have, not again - to protect us on a molecular level. I was the only one who could do it. Well, a little help from April wouldn't hurt, of course.

And so I did it. A well-planned run-in with Bishop, along with a lot of determination and a little ingenuity, and we were able to procure one of his massive machines for my lab. I set to work.

I learned three things. First, this tech Bishop had on hand; it was amazing and about a hundred layers of fascinating. Light years ahead of anything we have now. The ability to analyze a living organism's DNA and produce an accurate age is a distant pipe dream...and yet a handful of cheek swabs, some pressed buttons and a few seconds later, I had incredibly detailed age results at my fingertips.

Second thing: the four of us are true genetic siblings. Of course, we didn't need any sort of tangible evidence to know that - but it was still...nice to know.

And the third thing I learned (I'm actually taking a deep breath as I write this) was that Leo is actually the youngest of all of us.

Okay, so I know there are some things that you just can't get across through paper and ink. And maybe this is one of them. So let me reiterate here.

Leonardo is the youngest.

A simple but impossible fact, minuscule in the grand scheme of things. I couldn't believe it, but there it was. Leo's new position meant ours were as such: Raph was now, biologically, the eldest, I was now second-eldest and Mikey was now second-youngest. After the discovery, I think I sat in shock for a good hour. When I snapped out of it, I knew I had to go to Master Splinter.

The shock was visible on his face (which will always be disconcerting, no matter how old I get). He sat for some time in silence, and I didn't dare interrupt. I had a lot to think about, anyway. What in the world were we going to do with this? How would we tell the others? "How accurate would you consider this information?" he asked me, and when I rambled a bit - something about how the margin of error on a machine like that was absurd - he stopped me with a hand on my shoulder, gave me a reassuring smile and said I had done well. Though he added, "I'm afraid the timing of this revelation could not have been worse," and I knew he was talking about Leonardo's drastic attitude shift.

"We can't keep this from him," I said, and I knew I was right.

Though Splinter looked a little weary, his resigned sigh clearly showed that he agreed. Then with a nod, it was decided. We would tell the others immediately.

We all met in the dojo, mostly because Raph and Mikey were already in there, having an impromptu sparring match. Leo was in his room, but surprisingly enough, came down without a problem when Master Splinter called for him. I sat down with my brothers as Splinter stood before us, but Leo hung back, standing a bit away from us. His unwillingness to join us threw me off, and when Splinter urged me to share my findings, my brain froze and I panicked a little. I didn't know how to begin. But I know I got it out somehow, because I can still remember the exact expressions on each of my brother's faces when they heard me say it.

Mikey's reaction was textbook, almost comical surprise, complete with wide eyes and mouth hanging open. Raph looked shocked in a frowning, incredulous way. He almost looked affronted. And Leo...since I had turned my face to my brothers as I revealed the discovery, I could peripherally see his expression change. I remember glancing his way to gauge his reaction better, and being startled to see that his shock had dissolved the perpetual angry face and brooding aura for a moment. But suddenly the shock gave way to this...almost scared, lost look on his face, and he took what looked like a few involuntary steps backward. Then just as quickly, he looked sharp and furious, and then he left the lair and didn't return until morning.

While he was gone, we had the chance to talk things out a bit. Raph seemed to take the news well, though he was unusually quiet. Maybe he was feeling conflicted about finally getting what he wanted - a chance to legitimately challenge Leo's authority- at the cost of further alienating Leonardo? Fantasizing about becoming leader? Or maybe feeling the responsibility of being the eldest fall upon his shoulders? And Mikey...easy-going, adaptable Mikey. When the flabbergasted phase wore off, he warmed quickly to his new position in the family. Even joked about how he might be growing in a beard, that's how mature he suddenly was. I think they'll be all right.

Leo on the other hand...well, it's still strange for me to pinpoint him as the source of ANY trouble. But he's definitely making this situation very difficult. Our first excursion topside after the age revelation was a complete disaster. Leo was even less communicative than usual, constantly rushing ahead and leaving us behind instead of leading. I could see that Raph was trying his best to be business-as-usual, but little things (like the fact that his teeth seemed permanently clenched together) suggested he was chafing under our now youngest brother's command. Mikey seemed a little nervous and spacey, our teamwork was especially clumsy and Mike ended up with a bruise not from the bad guys, but from my bo. Oops. To top it all off, we were almost spotted by one of the groups we try our hardest to avoid: teens with cellphones.

We continued on like this for a few nights until things finally came to a head (It probably didn't help that this was the same day Raph decided to debut a new nickname for Leo). Stopping a mugging and a bodega robbery apparently hadn't been enough to distract Raph and Leo from antagonizing each other, because they went for each other's throats the second we got home. Master Splinter managed to separate them, and declared that it was impossible for us to continue as a team without being united. He had hoped we could resolve the issue by ourselves, but as that didn't seem to be happening, he was now stepping in. The position of leader would have to be re-evaluated. He's been meditating on it ever since...that was a few days ago.

Like I said before, the last few weeks have been rough.

As for me, I guess...I guess I'm okay with all of it, honestly. Not that I personally had a lot of upheaval to get used to, as second oldest isn't all that different from second youngest. Not quite one and not quite the other; been there, done that. I suppose the only difference now is whether or not I'll be expected to train as Raph or Leo's second-in-command. It's all a bit up in the air right now...but I hope either way I have time for the myriad projects waiting on my work table.

There are hierarchies everywhere, whether we notice them or not. Just a matter of getting used to them. But I'm worried about what will come out of disturbing ours, especially with Leo the way he is now. Difficult as it is, we haven't stopped all efforts to get through to him. I know our brother is in there somewhere, and I know we'll get through this.