The laboratory underneath the Ponyville library may not have been the very last thing one might imagine to find underneath the sprawling tree, but it would at least have to be in the bottom 5%. Between the tree's gnarled roots were a mind-boggling number of shelves packed with chemical, physical and magical apparatus. Glowing stones were packed in next to racks of test-tubes. Strange-looking electronic analysis hardware was whirring away next to a what appeared to be three glowing balls hovering in the middle of a glass vacuum bell. Thick, opaque green liquid with... something moving in it was suspended in a giant glass column still.
In the center of it all, a purple unicorn was using a small piece of chalk, surrounded with a glowing purple miasma and apparently scratching out marks on its own, to make corrections to some complex-looking mathematical equations hastily scrawled on a movable blackboard. A small purple reptile stood nearby, yawning and occasionally making notes in a clipboard.
After many long minutes, Twilight Sparkle stepped back from the blackboard, apparently satisfied with her changes. "Alright, this time for sure," she said, as she scanned over the equations one more time. "Spike, stand back."
Spike moved back with another yawn. "Yeah, I've heard that before," he mumbled, but nevertheless walked well away from Twilight, plopping down heavily at the bottom of the staircase that led up to the rest of the library.
Twilight braced her hooves and lowered her head. She aimed the point of her horn at a small pumpkin that had been carefully placed on the floor of the lab. She grit her teeth and squeezed her eyes shut, straining, and a faint purple glow began to manifest around her horn.
A gentle swirling wind started to grow in the lab, and Spike, suddenly fully awake, slammed a claw down on his clipboard, the papers beginning to flap in the breeze. "Twilight?"
Twilight Sparkle took no notice, her hooves digging into the floor, sweat beading on her forehead with the strain. The wind started to get stronger, and the pumpkin started to glow a faint purple. Sparks spat from Twilight Sparkle's horn, her mane flying wildly in the unnatural wind.
Spike clambered up a few more stairs, holding his clipboard tightly under his arm to keep the papers from being ripped away. The wind was lifting his scales and pushing hard on his green dermal plates, and he could faintly hear the sound of shattering glass as test tubes and flasks were blown over in the gale. "Twilight!" he shouted into the wind.
The glow surrounding Twilight Sparkle's horn continued to grow in intensity, filling the dingy laboratory with a blinding, violet-tinged light. Her horn was shooting sparks in every direction. The pumpkin was now wreathed in purple and seemed to be... disappearing?
Spike gaped as the pumpkin grew translucent, insubstantial. "Twilight! It's working!" he shouted, his voice lost in the wind.
Twilight Sparkle wouldn't have reacted even if she had heard him. She was too deep into the spell now, lost in the blazing energy that now wreathed her entire body, rather than just her horn. Her eyes snapped open, solid white and glowing. Her mouth opened and a piercing scream split through the roar of the wind, and in its own turn was drowned out by the earsplitting crack of an explosion...
A short moment later, Twilight Sparkle stumbled to her feet. Her lab was a shambles. Broken glass littered the floor, as did fallen and damaged books. Small pools of liquid had formed where flasks and canisters had spilled. The electronic monitoring hardware was on its side, the entire rear panel caved in, dented in the shape of a small baby dragon. Spike was just beginning to get his own bearings after having been blown right off the stairs and sent flying headfirst into the no-longer-functioning metal device.
And everything, absolutely everything, was covered in a thin, slightly sticky layer of pumpkin puree.
Hours later, Spike and Twilight unhappily stumbled up the stairs into the main library. The bright western sun streamed in the upper windows. Twilight had earlier intended to open the library right after lunch. Instead, after the succession of failed experiments, then cleaning the lab of pumpkin sludge, broken glass and spilled chemicals, it was already late in the afternoon.
"Twilight," Spike said, a bit petulantly. "It's late, and we still need to wash this stuff off. Maybe we shouldn't-"
"Open the library?" Twilight replied, finishing the sentence. "I think you're right, Spike." She ran a hoof through her matted, soggy mane, scraping a few pumpkin seeds out. "We both need a bath."
Murphy, unable to resist such an obvious opening, intervened. Twilight and Spike both groaned as a knock came at the library door. "Coming," called Twilight, weakly, while Spike quickly retreated for the washroom, before Twilight could decide she needed him to stick around after all.
The door swung open, and there, in the doorframe, stood Big Macintosh, Applejack's elder brother. He stepped partway inside. "Howdy, Miz Twilight," he began, and then stopped, his usual small smile changing to an equally small and subdued frown as he noted Twilight's bedraggled appearance. "Maybe I should come back later."
"No, that's alright," Twilight sighed, not quite believably. "What can I help you with, Big Mac?"
Macintosh's frown lessened to a faintly disapproving neutral expression. "I need a basic algebra book. Applejack's wantin' to learn how I do the family accounting, and, well, she never took to school, so I gotta catch her up."
Twilight blinked and her brow furrowed in consternation, her discomfort and dissheveled appearance momentarily forgotten. "You're going to teach Applejack math? Don't you want her to talk to someone with some... y'know..."
Macintosh looked faintly amused. "Are you assumin' I don't know about math, Miz Twilight?"
Twilight blushed slightly and looked away. "Well, um... I'm sorry, I didn't mean to assume..."
Mac chuckled. "Can I come in?"
"Oh, right! Sure," Twilight replied hastily. The large red pony stepped inside and the door swung shut behind him. "So... Math books?"
"Eeeyup," replied the taciturn Macintosh. "I don't have mine no more, sold 'em all after college."
Twilight was looking around in confusion to see where Spike had gone, and nearly tripped over her own feet. "You went to college?"
Macintosh chuckled. "Sure did. Got me a bachelor's in mathematics. Minor in ag science."
"You're a mathematician?" Twilight's left ear began developing an interesting twitch.
"Nope. I'm a farmer," Macintosh said with a huge grin. "I decided to come back and work the orchards when pappy died, instead of gettin' my master's... Wouldn't have been right to leave AJ to do it on her own."
"I can understand that," Twilight said with a slight grin as she began to yank textbooks off the shelves one at a time. "Sorry, Mac, I just never took you for the bookish type."
Macintosh rolled his shoulders in a shrug. "'s alright, we all make mistakes." He started nosing open books as he spoke, pushing them away one at a time when he didn't find what he wanted.
Twilight and Macintosh lapsed into silence as more and more books were pulled down and rejected. After she had cleared the entire math section, she then put a hoof to her forehead. "Oh, no! I forgot... I took all of the advanced math texts downstairs."
"Well, let's go take a look downstairs, then."
Twilight and Macintosh walked down into Twilight's still-in disarray but no longer entirely destroyed lab. Twilight walked across the lab to a small pile of books in various states of disrepair, and sighed. "I'm sorry, Mac, not all of these are... still... books. But you're welcome to borrow any of them."
Macintosh nodded as he walked over to look at the books himself. "Thank you kindly," he said, and then stopped, tilting his head at the movable blackboard. It was no longer in the middle of the floor, but, by dint of significant effort while cleaning, still bore Twilight's complex magical equations.
Twilight saw where Macintosh was looking, and chuckled nervously. "That's, uh... What I was working on earlier. It's supposed to be a new spell, but so far it just makes pumpkins explode."
Macintosh scanned over it, curiously. "Well," he said, speaking slowly as he read. "I only learned a little about magical field theory, but this looks interestin'." He stopped and reread scome of the scribbles, and whistled. "Differential equations. That's advanced work. I took ordinary in fourth year."
Twilight chuckled nervously, again, suddenly very self-conscious about having Macintosh looking at her work. "Well, we... kind of have different priorities in magical studies... Lots of calculus... Don't you want to see if any of these are the book you want?" she said, hopefully.
Macintosh walked over to the table and quickly nosed open several of the books that were most intact. "Eeyup," he said after opening his fourth book. "Introduction to Algebra." He picked the book up with his teeth and deposited it in his saddlebags.
"Thanks again, Miz Twilight," he said as he turned to head back up the stairs.
Twilight smiled in relief and turned to follow. "You're very welcome. And now I really need to get a bath."
Macintosh nodded as the two ponies stepped out into the library. He walked out toward the exit, and stopped. "Twilight... Your solution to your differential equation down there, you're integratin' over negative to positive infinity?"
"Um... Yes?" Twilight said, suddenly uncomfortable again.
"Well, seems to me," Macintosh said, slowly. "That's a power distribution equation, ain't it? What's the negative side represent? Goin' below some kinda energy input floor? It just don't seem to add up."
Twilight blinked in confusion. "The negative side? Well, it's..." Her mouth moved silently for a moment, before she threw herself at Macintosh and swept the larger pony up in a hug. "That's what's wrong! Big Mac, you're a genius!" She then let him go, blushing at the bits of dried pumpkin that were now stuck in Macintosh's mane. "Oops... Sorry."
Macintosh smiled. "'s alright. Glad I could be of some help." He then turned and walked out the door, and Twilight pulled it closed behind him.
"Morning, Applejack! How's business?"
The seven-day forecast the weather teams had posted for the week had shown the next day would be clear and sunny, and so Applejack's apple stand was set up in the Ponyville town square. It was midmorning, and business was slow, so there was time for Twilight to stop and say hello.
"Twilight," Applejack replied, a slight, sarcastic edge in her voice. "I'm plum grateful to you for helpin' Big Mac find that math book. I sure did enjoy spendin' four hours last night learnin' about functions and linear equations."
Twilight looked downcast, and nervously pawed at the ground. "That bad?"
Applejack sighed. "I'm sorry, Twi, I shouldn't snap at you. Truth is, I asked Big Mac for help learnin' this stuff, so's I could help work on the books at the farm. I was just never no good at math, not like Mac."
Twilight nodded. "I didn't know Big Macintosh knew anything about math until yesterday."
"Shoot, Twi, I coulda told you that," Applejack said with a chuckle. "Big Mac's been takin' care o' Sweet Apple Acres' books and finances since pappy died. Granny Smith's th' only other one who's real good with bookkeepin' and she's not up to doin' books for a whole workin' farm no more. I feel bad about that, Big Mac does as much work as me applebuckin' and tendin' to the crops, but I can't help him none with his work. So I asked if he could teach me enough to do some o' the bookkeepin'. I can't stand to see my brother doin' so much more work than me."
Twilight looked confused. "Don't you do most of the sales work, though, and hauling apples to town?"
"Well, that ain't really work, Twi. I just stand around for a few hours and ponies come gimme a few bits for apples and pies."
"And the baking?" Twilight asked, going from confused to skeptical.
"Well," Applejack replied, hedging, "That ain't really work, neither. I mean, I like bakin'. Even gives me an excuse to go down to Sugarcube Corner and visit with Pinkie and the Cakes. 'Tain't the same as Big Mac spendin' his whole day inside, workin' on sums."
"Well, maybe Macintosh likes working with numbers, just like you like baking."
Applejack snorted. "Yeah, that's what he says, too. Come on, Twilight, who'd wanna spend the day inside doin' math?"
"AJ, I spent yesterday inside doing math!"
"Well, but, that's different, Twi," Applejack said, backpedaling hastily. "I mean, you're..."
"I'm what?"
"An egghead!" A familiar voice called from overhead. A moment later, a cyan pegasus with a brilliantly colorful rainbow-striped mane dropped down from the sky, landing gently next to Applejack's apple stand. "Hey, guys," Rainbow Dash greeted Applejack and Twilight, cheerfully. "What are we talking about?"
Twilight glared at Rainbow. "I am not an egghead. And we were talking about Big Macintosh and his love of mathematics."
"Yeah, Twilight's tryin' to tell me that Mac likes spendin' his time doin' books."
"Oh, yeah," Rainbow Dash said. "Mac loves that stuff. He once helped me with some tricky ballistics calculations when the weather team was trying out some new ways of dispersing big thunderheads, and the whole time he was grinning like Pinkie Pie that time she ate a whole bag of sugar."
"What, really?" It was Applejack's turn to be confused and dismayed. "Well... Shoot. Now I really feel bad for Mac."
"Well, you're learning some math so you can help him out, right?" Twilight asked.
"It ain't just that, Twilight. Mac always said he was fine with leavin' school after gettin' his bachelor's and that the farm was where he belonged." Applejack sighed. "I guess I just never wanted to realise how much of a sacrifice it was for him to come back to the farm instead o' continuin' his education."
"Well, didja ever ask him?" Asked Rainbow Dash, archly.
"No, I don't suppose I ever did," Applejack said, before stamping her hoof determinedly. "But I will this evenin'!"
"That's great, AJ!" Twilight replied, smiling brightly, before producing two bits. "Oh, uh... Can I get an apple?"
"Make it two?" Asked Rainbow Dash, hopefully.
Rainbow and Twilight walked away from the stand, Twilight's apple floating in front of her, Rainbow's tucked safely in her saddlebags. A line was beginning to form as they left, and Applejack returned to the business at hand.
"Ballistics calculations?" Twilight asked, a hint of amusement in her voice. "Do I get to call you 'egghead' now?"
"Yeah, yeah," Grumbled Rainbow Dash. "Every pegasus learns basic external ballistics and gas dynamics at flight school, and weather pegasi have to know even more than that. I hate it, it's why I dropped out the first time."
"But you're a weather pegasus now, right? You must have learned it all pretty well."
Rainbow Dash made an expansive shrug with her wings. "I was never bad at it. I know all that stuff, it's just... turning it into numbers that's hard."
Twilight nodded, unconsciously sliding into an investigative mindset. "Turning it into numbers? Could you explain that?"
"Isn't it obvious?" Dash asked. "It's all just there, right? I don't need numbers to tell me where the jetstream or the cloud deck is, or the difference between a full cloud and an empty one. The weather's just... the weather."
Twilight responded neutrally, but was quite boggled to hear this, even from an ace flier like Rainbow Dash. There were whole fields of physics and mathematics devoted largely to the things that Rainbow Dash had summarily dismissed as "just there". "Do you have to file many reports?"
"Nah, they don't make us do a whole lot of paperwork except in an emergency. I had to file a miss report before we got cleared for that big storm a few months ago, when we forgot that there was a scheduled shower." Rainbow Dash blushed slightly, a slight red tinge under her blue fur. "I was... kinda late on the miss report too, actually. We almost didn't get cleared in time."
"Well, Rainbow, in the future, if you need help with any of the math, you can always ask. I'm pretty sure we have some books on weather systems and gas dynamics at the library."
"Oh, hey, thanks, Twilight," Rainbow Dash replied, cheered by the kind offer. "Oh, could you get my apple out for me?"
The night was dark and clear as Applejack finished pulling the blinds down at Sweet Apple Acres. Applebloom and Granny Smith had both been tucked into their respective beds, and Applejack and Macintosh sat down at the kitchen table, the beaten-up copy of "Introduction to Algebra" between them.
Big Macintosh leaned down to nose open the book, then leaned back as Applejack gently rested a hoof on the cover.
"Wait, Mac. I got some questions for you. About your schoolin'."
Elsewhere, Rainbow Dash settled in on the couch in her ostentatious cloud castle. Fireflies flitted around, illuminating the large living room space, as Rainbow sat down with two things she hadn't bothered with much in quite a few years: A pair of reading glasses, and a copy of "Cloud Dynamics: A Weather Pony's Illustrated Primer".
Spike and Twilight were upstairs in the library, in their shared bedroom. Spike was seated, quill in hand, at his small desk, and Twilight lay face down on her bed, an open copy of "Practical Physics for Pegasi" lying face down next to her.
Dear Princess Celestia,
Today I learned that you should never underestimate your friends. Just because a pony is big and quiet, or understands things differently than most people, doesn't mean they're not as smart as anyone. If you give everyone a chance, you might find that your friends have skills that you never would have even guessed.
Your faithful student,
Twilight Sparkle
Spike briskly rolled up the parchment and incinerated it with his dragon breath, transforming the scroll into magical smoke that flew out the window, drifting in the direction of Canterlot. "Sent!" said Spike, finally. "So, Twilight... You think you'll get that time travel spell working tomorrow?"
Twilight Sparkle sighed and rolled over onto her back. "I don't know, Spike. Mac's suggestion was a good one but my theory might still be fundamentally flawed-"
Twilight was cut off as a strange, hollow roar filled her bedroom, followed by a blinding flash of purple light. Twilight and Spike both recoiled in alarm, and then looked down at the floor in wonder.
There, on the wooden floor of the bedroom, last vestiges of a purple glow fading from its orange husk, sat a pumpkin.