TMNT is not mine.

Crack. That is all. Oh. And a few cuss words. But that's about it.

Stand back everyone, we are going to try science!

There are some days when it was just not worth being the 'smart' one.

This was an unfortunate truth Donatello had come to understand very early on in his life when he realised that the many things that interested him held little appeal for the rest of his family. However, when one was a mutant excluded from the majority of society, one simply resigned themselves to the fact and did not dwell on it.

Usually.

Donatello grunted as he dropped to the ground to avoid a split kick from Leo. The two were sparring, Don had decided he needed a break from his lab and Leo was always a good sport for a fight. There was no testosterone posturing that he'd have to deal with if he was up against Raph. And Mikey was simply too annoying to spar with under most circumstances.

And, speaking of Mikey…

Donatello had a well-developed sense for when mischief of the Michelangelo type was brewing in the direction of his lab. And right now, that sense had just gone Def-Con 1. He hesitated for the slightest moment but it was enough for Leo to take advantage of it and send him hurtling into the wall.

"Getting a little distracted there?" the other turtle chided with amusement, offering a hand to pull his brother up.

Don gripped Leo's hand and stood. "Sorry," he said. "I just thought-"

"DONNIEEEEEE!" Mikey's voice boomed through the lair. The turtles in the dojo flinched at the volume. There was the sound of feet hitting the ground hard; Mikey had probably jumped down from the upper floor. Then he padded off…in the definite direction of Don's lab. "DON! DOOOOOOOOOOOOON!"

The turtle in question rolled his eyes at his brother while Leo winced in sympathy but neither of them spoke a word. It wouldn't take long for Mikey to locate his unfortunate brother but that didn't mean they had to speed up the process.

There was the sound of the lab door crashing open. Both of them could almost see it now, like a wrathful, chaotic force of nature Mikey would be standing in the doorway as he scanned the room with his intent gaze. Then, seeing that it was empty of mutant turtles but filled with lots of shiny and interesting gizmos, Michelangelo would venture forth to unleash absolute havoc.

Leo closed his eyes and placed his head in his hand as he listened to something crash. "Whoops!" Mikey called out. "That…that wasn't important, right? Because I totally did not break it."

Donatello was entirely unfazed. "One of these days," he said, very softly to Leo, "I am going to be working on something dangerous. And he will break it and it'll kill us all."

"…well, at least he'll be at ground zero," Leo said philosophically. "We'll have a few seconds of Mikey-free existence before we die horrible, painful deaths."

His brother snorted with dark amusement and then opened his mouth to reply when-

-"Oh shit-" Mikey called out just as-

-sounded like glass breaking-

CRASH.

"CRAAAP! DONNIE! HELP!"

"Give me the bad news, doc," Mikey said bravely as he watched Don's solemn face. "I can take it. It's bad news, isn't it?"

His brother finished bandaging Mikey's leg then looked up with a frown. "Firstly, I am not a doctor, so don't call me that. Secondly, well I'm pretty sure I've managed to get all the glass out," he said, giving one last pat before releasing the limb and pushing it back to its owner. "You're lucky that it wasn't a big cut or it didn't slice any major blood vessels. I just wish you'd been a bit more careful, this could have been easily avoided."

The injured turtle paused for a moment, his mouth hanging open as he struggled to formulate a response. "No," he said at last. "My leg's going to be fine, I know that. It's the other thing I'm worried about."

Donatello was rearranging his medical supplies and putting everything back in its proper place. He gave an absent affirmative hum. "What other thing?" he asked distractedly.

"Well, you know. There was something in that beaker right?"

"Yes, it was diluted sodium chloride. It was part of my galvanised batt-"

"Shitshitshitshitshit. I'm dying aren't I?"

"Not that I'm aware of," Don replied automatically. A second later he processed his brother's words, did a double-take and turned back to his brother. "Wait, what?"

"Oh great, I'm not dying. I'm mutating, aren't I? I know I am." Mikey grasped his head in horror. "I'm going to turn into a girl turtle!"

It was at this point that Donatello realized he had absolutely no idea what was going on in his brother's mind. "Mikey," he began slowly, "I'm pretty sure-"

"-That I'm turning into a girl!" the other turtle pointed an accusing finger at him. "This is all your fault! You with your mysterious substances just lying around in your lab! Why do you even bother making that shit? Or keeping the strange stuff we find in our enemies bases? It's always bad news and you keep bringing it home like it's a little lost puppy. Are mystery substances the little lost puppies of the science world? I think they are because you can never leave them behind and you just got to have them but you never bother taking proper care of them and then-"

Donatello blinked once during this tirade. He cast a longing glance at his bo, innocently and alluring propped up against the wall. No, it wouldn't do to hit his already injured brother. But honestly, he was just being stupid.

"-And now I'm turning into a girl! A GIRL! I'm gonna grow boobs and then you guys are all gonna be weird and perverted and I'm gonna cry a lot, like seriously a lot because you won't get that I haz feelings now and I won't be able to fight with any decent skills because girls are pathetic-"

Hmm…oh hey, bandages. Don turned them over in his hand and then eyed his brother's beak. Yes. That could work. He took a step closer.

"Don't touch me you incestuous pervert!" Mikey screeched, scrambling backwards on the bed.

At this, Leo couldn't take it any more and poked his head into the infirmary then eyed his two brothers questioningly. "Alright Don, how much of the good stuff did you give him? Or is there something I should know...?"

"I didn't give him anything," Don replied acerbically. His eyes darted back to his bo, his original plan was looking more tempting by the second. "Mikey is just being an idiot."

The brother in question folded his arms across his 900% flat plastron and glared sullenly. "It was a strange liquid in his lab. Anything could happen, that's all I'm saying."

"I'm certain that liquid was harmless," Leo soothed, though even he couldn't hide the somewhat doubtfully glance that he threw Don. The turtle was a mad scientist after all.

Donatello couldn't take this anymore. "It was sodium chloride!"

"SEE?" Mikey shrieked hysterically. "It's a mysterious science thing!"

"It was SALT," the other turtle snapped. "It was just. Salt. In water. THAT WAS IT."

The other turtles fell silent at this outburst. Michelangelo ducked his head in embarrassment while Leo raised an eye-ridge in a quiet, oh-that's-what-it-means-oh-how-silly-of-me-hahahah a…whoops. With an irritated huff, Don shoved the bandages into Mikey's plastron then stalked out of the room.

He had a lab and some salt water to clean up.

There just some days it wasn't worth being the 'smart one.'

Don sidestepped Leo's fist then swept his legs out from under him. About an hour after he'd cleaned his lab, Leo had quietly come up to him and asked if Don wanted to finish their spar. And now, as they traded blows, the afternoon's hysteria with Mikey was slowly forgotten and Donatello felt all his tension melt away.

It was, of course, not to last.

There was the sound of the lair's main entrance opening, then loud, heavy footsteps stalked across the living room to Don's lab. The two turtles' sparring slowed to a halt.

"Don?" Raphael's voice called out.

They listened as the lab door opened. There was the sound of things being lifted and moved apart as one turtle searched for another. It wasn't exactly uncommon for Don to be buried so deeply in his work that one had to actually search to find him.

Then something shattered.

"FUCK, DON-!"

With a sigh, Don padded over to the dojo door, Leo following a step behind him. The two turtles made their way over to the lab, where they found their brother casting desperate glances around the room, a broken beaker at his feet.

"What is it?" Don asked flatly. Honestly, having his lab invaded once in a day was bad enough. Then he'd had to deal with Mikey's histrionics. This was just too much. "Surely you don't need me to figure out how to sweep up broken glass."

"I got some of it on me!" Raph gasped, pointing at his feet.

Utterly unsympathetic, the brainy turtle cast a bored look at his brother's feet. "And?"

"Fuck! I'm going to mutate into a human now, aren't I?"

"No, Raph. Science doesn't work that way. Just no."

END

AN: To be fair, this is a fandom that is based entirely on the action of a mysterious substance. But there is only so much misuse of it that I can take before I write crack.