Just a little one-shot drabble I wrote to celebrate Pi Day, some of you may find it cliché but I don't care, somebody had to do it. Yes I'm still working on "Love is Complicated as Shell" so don't worry. It may surprise you to know this but I do not own tmnt and I am not making any money by writing this. I know, I'm shocked too.

It was the 14th of March; the snow was thawing as winter made way for spring. Daylights savings time had just begun and now the citizens of New York City grumbled in discontent, maneuvering through crowds, they trudged their way to work and school an hour earlier than usual, setting the pace for a long and busy day.

Deep below the city streets, a family of more extraordinary citizens was far less concerned over the increase in morning traffic…

Donatello leaned forward to settle his elbow on his desk, propping his head up in one hand as he listlessly scrolled down the page on his computer monitor, his mind only barely registering the words on the screen;

"... the exact proportion between the diameter and the circumference can never be expressed in numbers..."

He knew this already, it wasn't the first time he'd read "Synopsis Palmariorum Matheseos" but given the day's date he'd felt it was fitting. At least it was something to do.

It was one of those rare, quiet days in the lair- well, "quiet" being a relative term anyway- even in the confines of his lab, Donatello could still hear grunts of exertion followed by dull thuds of flesh hitting vinyl as his hot headed brother mindlessly pummeled away on his punching bag in the other room.

The faint sounds of automatic "pings" and "beeps" , the thwack of plastic hitting wood as the spring loaded plunger was pulled back and released farther than necessary, the consistent fluttering of flipper buttons being assaulted as well as Mikey's enthusiastic cries of victory told him that the youngest was showing their pinball machine no mercy.

He couldn't make out any sounds from the television, which meant Leo was probably in the Dōjō or in his room reading his Space Hero's comics- as long as he wasn't bickering with Raph, Donatello truly didn't care how "big brother" decided to spend his free time.

Free time; what a novel concept that was.

Morning training was done, and for once so were their typical daily chores. Nothing in the lair currently needed repair (yet) and he had already given the Shellraiser a complete maintenance check yesterday. Security systems on the tunnels surrounding their underground home had all been updated less than a week ago and were still running as smooth as WD40 over a ball bearing. All of his retro-mutagen experiments were either spinning in his centrifuge or taking the time to settle in the cooling unit, none of which needed his supervision at the moment. To top it off, nightfall was still a few hours away which meant he didn't need to get ready for patrol anytime soon.

Honestly, the purple-banded turtle couldn't remember the last time he found himself with so much extra time on his hands. Usually his "to-do" list stretched a mile long. Even more surprising was that he hadn't been sure what he wanted to do with his sudden lack of tasks.

He'd written down hundreds of ideas that he'd wanted to tinker with for some time now but had never had the chance to get to- and now, with literally hours available for him to do just that, he found himself extremely unmotivated.

All the spare parts that he'd hauled into their makeshift garage from the city dump, the scrap metal that usually called to him, practically begging for him to take them apart and meld them back together- they were silent now.

His stacks of notes littering his desk, waiting to be sorted and filed, held zero interest to him. Rather than seeing it as a necessary task that he could finally get done, the notion seemed almost oppressively mundane.

If he'd been in a better mood, he might've laughed at the irony; He, Hamato Donatello, the turtle who most often complained of having the busiest schedule- was bored.

…And maybe just the tiniest bit lonely.

He'd even toyed with the idea of seeking out 1 of his brothers to find a way to pass the time, but quickly dismissed it. Aside from their trips to the surface and daily training, the 4 of them didn't really "hang out", not since they were little kids anyway.

It's not that they didn't care for each other, they were just so different;

Leonardo spent his free time with extra practice, meditation, glued to the television watching the same clichéd space show he'd already seen hundreds of times over to the point where they were all certain he could quote every episode from memory, or reading the vintage comics based on said clichéd space show.

Experience had taught him that asking Leo if he wanted to do anything was akin to asking the oldest to drag him into the Dōjō to practice katas together, or rather, have HIM practice katas while his brother pointed out his mistakes. As far as Donatello was concerned, none of that sounded even remotely appealing at this moment or any other.

Raphael's preference of reading material was limited to magazines that centered on sports, fitness or motorcycles. If he wasn't engrossed in that, he could be found working out or in his room doing… well, he didn't know what exactly, Raph's room was strictly off limits and there was a very painful penalty for anyone stupid enough to trespass. While Donnie enjoyed looking at the newest motorcycle designs, (anything with an engine fascinated him really,) reading was more of a solo activity.

Raph's idea of spending time with his bro's involved sparring or challenging them in 1 of the old arcade games that Donnie had been able to salvage and repair. He wasn't really in a competitive mood right now, nor did he have any desire to be pummeled into the Dōjō mats.

Michelangelo also seemed to live on a different plane than Donatello (and possibly from the rest of them as well). Little brother loved to scare himself silly as he got lost in cheesy horror comics, work himself into a frenzy over cartoon shows, or mindlessly hum along to whatever song he was listening to through his headphones while he danced and jumped throughout the lair without a care in the world.

Asking the youngest to hang out would be taken as an open invitation to snoop around in the lab creating a colossal mess, or trying to convince him to help prank their older brothers only to turn the pranks on the purple-banded turtle if he refused.

Donatello couldn't begrudge his brothers their interests. It was their differences that made them who they were and he wouldn't change that for anything. But as much as he loved his brothers, he couldn't help but feel a little disappointed that he seemed to have so little in common with them.

As much as Leo and Raph seemed to be at each other's throats, most of their sibling rivalry was good natured (sort of) and the2 seemed to thrive on competing in just about everything. If anything, it seemed to bring them closer.

They all claimed Mikey was annoying, but he also had a way of pulling them out of any funk. They all thought his pranks were funny so long as they weren't the victim, and somehow the orange-banded turtle could convince them to join in the most absurd games that none of them would ever have considered if he hadn't given them his patented turtle/puppy-dog eyed look. As crazy as his ideas were, they were also fun.

But what did he have? Other than Ninjitsu, what interest of his could his brothers possibly share?

Leo often praised him for his expertise in science, even sought him out if he thought it could solve their problems. But that's as far as it went. Leo didn't care HOW Donnie figured things out or got them to work just so long as he got results. If he was in an agreeable mood he might smile and nod encouragingly while he tuned him out, but most of the time he just shushed him by asking for the shortest explanation possible.

That was understandable when time was of the essence, but outside of patrol or a potential crisis, Donnie would've liked to have a more detailed discussion about some of his discoveries or the fascinating inner-mechanisms of some of the more advanced technology they came across- but any attempt he ever made at such conversations was answered with "not now." Admittedly, it had taken him a few years, but eventually Donatello had figured out that "not now" was the eldest's way of saying "not ever."

Raph, though he rarely mentioned it, seemed to really enjoy anything the purple-banded turtle built that had an engine; the Shellraiser, the stealth bike, the patrol buggies- if it went fast he liked it, if it had weapons that made things go BOOM, he loved it. His immediate older brother may not have had any interest in computers or chemistry, but apparently mechanics and automobiles were a worthwhile endeavor. Unfortunately, it was also 1 that the turtle in red seemed content to leave up to Donatello. As much as he enjoyed using the various modes of transportation his brother came up with, even going so far as nearly complimenting him, he showed no interest in learning how to build or repair them.

That was a shame; as much as Donatello loved working in the garage, he would have enjoyed it more if he had someone to work with. Most of his dialogue with Raph consisted of half-hearted insults and volleying sarcastic remarks back and forth. Enjoyable, yes, but probably not ideal bonding material.

Mikey… The problem with Mikey was… well, he was Mikey. It was impossible to follow his youngest brother's train of thought and he had long since given up any hope of doing so. Michelangelo's interest in science was dependent on how shiny the buttons were. Conversing about the technical processes behind his research was pointless as any words he spoke that were longer than two syllables went through one ear and out the other. As far as working together- he barely trusted his brother with a dust mop let alone any of his tools.

It wasn't that he thought Mikey was stupid (though he sometimes hinted at that through less than kind remarks when he was feeling irritated) it's just that his brother was… on a different level… a VERY different level. And it was nothing less than frustrating.

Worst of all, while each of his bros' shared an aversion to his likes and a limited tolerance for his "geek speak" as they oh so eloquently termed it, they had no problem enjoying each other's company and were perfectly content to leave him alone to his own devices while they spent time doing activities that they all enjoyed.

That kind of stung. He knew it wasn't intentional, but it didn't stop him from feeling just the tiniest bit left out-

"What'cha doing?"

"GAHHH!"

He had been so lost in his thoughts he hadn't noticed that the sounds of the pinball machine had ceased, nor had he heard the youngest enter the sanctuary of the lab. (In the back of his mind he was certain Master Splinter might've already given him a lecture on this, something about being a ninja and awareness of your environment, perhaps?)

Having nearly fallen out of his chair, Donatello clutched at his chest to feel the heavy palpitations of his heart, focusing on slowing his breathing so he could shoot a glare at his orange-banded brother.

"Don't DO that!"

Michelangelo however wasn't at all phased by the harsh tone or even concerned about the fact he'd almost given his genius brother a heart attack. He was more interested in why the normally busy turtle was being so quiet.

He'd spent the last half hour trying to beat Leo's high score with little success and needed something else to do before the boredom melted his brain. He'd decided to seek out his immediate older bro, but he knew if the turtle in purple was in the middle of a project there was a good chance he'd be tossed out on his shell. It was a well-known fact that Donatello could get a little cranky when he was working on something.

His curious eyes locked onto the computer screen.

"What're you reading?"

He'd thought Donnie would be spending his time working on mutagen, at least that's what his bro usually did whenever Mikey popped in to see if he was free. Skimming over the words on the monitor without really reading them, he noticed several pictures of… circles? And numbers. LOTS of numbers. And a little squiggly thing that looked like a doodle of a curvy table? It sure didn't look like Kraang-stuff, but then he really couldn't be sure. Donnie was the sciencey-guy, not him.

Seeing that the youngest wasn't even going to acknowledge practically scaring him out of his shell, Donnie let out a heavy sigh and tried his best to regain his composure so he wouldn't snap at his little brother.

" I'm just reading over the works of Sir William Jones…" it was better to just answer Mikey's question, once the freckled turtle realized there was nothing of interest to him he would go away in search of something better to do.

"…today is Pi day so I figured I'd-"

"REALLY?!"

Donatello blinked. The enthusiasm behind his brother's interruption caught him off guard. Turning away from his computer to give the smaller turtle his full attention, he was met with incredibly wide blue eyes staring at him as if he were made of pepperoni.

"Um, yeah. While Pi has been around since 1706 thanks to William Jones, it wasn't until 1988 that March 14th was chosen to celebrate Pi day. See, the idea came from this Physicist named Larry Shaw who-"

"Dude-dude-dude, hold that thought! I'll be right back- DON'T GO ANYWHERE, OKAY?"

Michelangelo was a green and orange blur as he rushed out of the lab.

Donatallo sat stunned for only a moment before shaking his head and turning back to his computer. He had no idea what had gotten into his bro. For a brief moment he had almost fooled himself into thinking that Mikey seemed excited by what he'd had to say. It was a ridiculous thought. More likely some random, crazy idea had popped into that empty head of his while he was tuning out his nerdy brother's "boring" history lesson.

Mikey had been going so fast he literally had to skid himself to a halt when he reached the center of the main room.

A holiday; Donnie said it was a holiday- and if T.V. had taught him anything (it had taught him so much) it was that holidays meant spending time with your bros! They were way overdue for some family-bonding; luckily, "Dr. Round-em-up-enstein" was here to the rescue! And his first stop was to snag and bag the turtle in red.

Raphael, as if sensing the youngest's thoughts were focused on him- an ability he'd developed over the years as a means of self-preservation, shot his brother a look of warning and let out a low growl from the back of his throat.

Raph had gotten bored with his workout and was now comfortably lounging on his bean bag chair, flipping through an issue of "Modern Ninja" without any real interest. He'd already read it a dozen times but it wasn't like he had anything better to do. Still, that didn't mean he was open to dealing with pesky little brothers either; he'd just been about to tell Mikey to get lost when the shell-for-brains relayed his conversation with Donatello.

"Wait, are you serious?" Raph narrowed his eyes suspiciously; this could very well be a prank after all.

"No lie, dude! I swear!"

To emphasize his point, Michelangelo placed one hand flat against his plastron over his heart while the other was lifted, palm out, prepared to swear on Ninjitsu and Pizza that he was speaking the absolute truth, so help him Splinter!

"Shell, why didn't he say so sooner?" Tossing his magazine aside, Raph leapt from his seat effortlessly, eager that there was finally something to keep him entertained. Plus, he might've, sorta, almost, kinda' missed the nerd, a little. Not that anyone else needed to know.

"Come ON! We 'gotta get Leo!" Mikey didn't have to tell him twice as they both ran into their oldest brother's bedroom.

Leo had been in the process of placing his "Space Hero's" comics back inside their protective plastic sleeves. As much as he loved re-reading the thrilling adventures of Captain Ryan and his daring crew, he just wasn't feeling it today. He was debating whether or not he should head into the Dōjō for some extra practice when 2 of his brothers decided to barge in through his door. Before he could admonish them for forgetting to knock, Mikey blurted out his recent discovery.

To say Leo was skeptical would be an understatement.

"Are you sure?"

"For real, bro! Donnie said so himself!"

Leo had to admit, he had never heard of such a holiday, but Donatello wasn't known for making things up.

The youngest was bouncing on his feet, biting his lip with a sense of urgency, as if it was taking everything he had and then some to not just yank his bro off his bed and forcibly drag him from the room.

A bit excessive for some random celebration they'd never even heard of, but it was proof enough that his claims were sincere. Judging from the way Raph was impatiently tapping his own foot, casting glances back out down the hall towards the lab, he was just as excited to see what their resident genius was up to.

Okay, maybe Leo was the tiniest bit curious too.

"Well, if Donnie says it is-"

"Blah blah blah, are you coming or what?"

Light blue eyes glared at green, but rather than allow himself to be baited, Leo chose to be the better turtle and ignored the rude outburst in favor of sprinting after Mikey. It would be nice to spend some time with Donnie for a change; he was always so busy…

Donatello found himself startled out of his thoughts for the second time that day when all 3 of his brothers burst into the lab. He really needed to start locking that door.

"Oh for the love of- HOW MANY TIMES HAVE I TOLD YOU NOT TO-?"

"We're all here D! Let's get this party started!"

"… Huh?" His tirade cut short, Donatello could only look with utter confusion at the youngest as he pumped his fist into the air.

Party? What the shell was Mikey talking about? Oh man, he hoped his bro hadn't been eating things out of the garbage again, he SO did not want to spend his free time dealing with questionable substance induced hallucinations…

Fortunately, Leo noticed his befuddled expression and had enough sense to clue him in;

"Mikey told us about your holiday and we came to celebrate with you."

Confusion gave way to shock. Had he really heard that right? This had to be some sort of gag, they couldn't really be interested. It was too "geeky".

Then again…

Looking once more at his brother's smiling faces, each looking at him expectantly; he couldn't help the warm, hopeful fluttering that had started to grow in his chest.

Suppose they were telling the truth? Maybe, just maybe, he had been underestimating his bros all these years… Was it possible they weren't all that different after all? The thought of finally having something intellectual he could share with his brothers was almost too good to be true, but here they were! Ready to actually learn something, and they looked EXCITED! He was starting to feel that way too.

"So, where is it?"

The gap-toothed grin that had been growing on Donatello's face shrank and was replaced with a furrowed brow and he contemplated the youngest's question.

"Where is what?"

"Duh, the Pie bro! I'm starving!" Mikey's head swiveled fast enough to give himself shell-lash as he scanned the lab, eagerly searching for the elusive treat.

"Speaking of which, what type of pie are we talking about? Or is there going to be more than one?" Leo also glanced about the room, though far more subtly than his baby brother- "I'm not really of fan of that cherry pie April brought over, but I liked the pumpkin 1 we tried last fall."

"There better be Apple or I'm not doing this." As far as Raph was concerned, apple was the only decent flavor there was.

"Oooh, Oooh, maybe it's a PIZZA Pie? Is it? Is it? IS IT?" Pie day was quickly becoming Mikey's favorite new holiday and they hadn't even started yet!

Donatello remained speechless.

Mikey cocked his head to the side, his eyes questioning as he contemplated his brother's lack of response when it hit him-

"Oh wait, do we have to make the pies? Is that why you were looking up that William guy? To find his recipe? I CALL DIBS ON LICKING THE BOWL!" Yep, best holiday ever.

"Hold on, nobody said anything about baking!" Raph was bored but not THAT bored.

"…Donnie? Are you okay?" Leo was a little more than concerned as he took a step closer to his purple-banded brother who had only stared blankly during their questions before heaving a deep sigh and folding his arms over his desk, burying his face in them.

Looking back at his other 2 bros for their insight, Mikey only shrugged and Raph was equally as helpful, crossing his arms and lifting an eye ridge as he stared down at Donatello, just as puzzled at his odd behavior.

Trying again, Leo gave a gentle nudge to Donnie's shoulder and asked if anything was wrong. The only response he got was a mumbled "…I give up."

With a final shared look between them, Leo, Raph and Mikey quietly made their way out of their brother's lab, the feeling of disappointment heavy in all of them. It wasn't the first time their brilliant brother had shut them out, but that didn't make it sting any less. They only wished they could figure out why Donatello always avoided spending time with them.