If It's Tuesday, They Must Be Mutations

by PropdowPony

Rating: everyone
Tags: Main 6, My Little Pony: Friendship is Magic, Comedy
Length: 7938

Mysterious malignant magical maladies mutate many mares, and more!

Mysterious malignant magical maladies mutate many mares, and more!

If the residents of Ponyville thought Monday was a bad day, they're really not going to like what they discover about themselves the next morning! Ponies all over town are suffering from...unusual abnormalities, and the hospital is getting pretty crowded. Surely there must be a cure for all this weirdness...right?

Cover art by 2135D!
Like Rarity with a bonus eye? Check out this cover art by Amante, and this cover art by FlutterPal!

Published 2013-07-07 18:30:01 UTC
Last updated 2013-07-07 18:30:01 UTC

If It's Tuesday...

If It’s Tuesday, They Must Be Mutations

by PropdowPony

If you had to blame anypony for the unfortunate circumstances of that fateful Tuesday, it might as well be Sassaflash, although some bad luck was involved, too. The day before, Sassaflash, the Ponyville weather team’s lightning expert, was responsible for grounding a cluster of active cumulonimbi which had drifted in around the boundary of the Everfree Forest. As dictated by procedure, she surrounded a nearby open field with yellow barricades, planted a couple dozen iron rods in a grid pattern, and put on her safety goggles and ear protection. She took three laps around the danger zone to make certain it was clear, and then carefully kicked each of the dark clouds one by one, forcing them to discharge their bolts safely into the ground below.

Sassy, however, was in a bit of a hurry. She had a lunch date with Caramel. Her weather duties had caused her to be late for their last three dates. When she was finished kicking away the lightning from the offending clouds, she noticed how much higher in the sky the sun had moved. She was supposed to have taken three more laps to survey the area for strays, but that fateful Monday, she only took two. She yanked up the rods, took down the barricades, and whisked off as fast as her wings could carry her, oblivious to the solitary little bruise-grey cloud which wandered in from the east.

This cloud was engorged with negative-charged particles, and desperately sought to find some positive-charged particles. Just ten minutes after Sassy departed, the cloud found them inside the machinery of Cloudsdale’s wind turbines #38 through #42. With a deafening crack, a bolt shot out of the cloud and shorted out the equipment in a shower of sparks, and the five turbines roared to life. Only one of these turbines was supposed to be running at a time.

The result was a sustained wind storm with gusts exceeding sixty miles per hour, blowing right through the Everfree Forest and into Ponyville proper.

Ponies rushed into their homes and sealed up their doors and windows. Trees groaned and swayed, their weakest branches snapping. Dust, debris, and newspapers tumbled and whipped through the streets. Market stands toppled over, their proprietors scurrying to gather their spilled wares. The windmill at Sweet Apple Acres spun right off its axle and crashed into the trees of the north orchard.

The damage could have been far more catastrophic had not Rainbow Dash, Cloudchaser, and Thunderlane responded to the emergency so quickly and rushed to shut down the malfunctioning turbines within minutes. Nopony was hurt, thank Celestia, but everypony’s Monday was thoroughly spoiled; Twilight Sparkle organized cleanup crews into teams, and the town gave a collective groan at all the work that lay before them.

Later that afternoon, Twilight and Fluttershy found Rainbow Dash tugging at a wagon wheel embedded in the thatch roof of the Sofa & Quills Emporium.

"Rainbow!" called Twilight. "You should really get going!"

"Let me just clear off a few more roofs," Rainbow shouted back, hovering in place as she struggled with the stubborn wheel. "And I still need to help Applejack fix their windmill."

Twilight and Fluttershy exchanged knowing smirks. You couldn't blame Rainbow for her diligence. She insisted on never leaving Ponyville hanging. Nevertheless, Twilight switched to her trademark lecture mode.

"Your Wonderbolts training in Cirrucuse begins at six tomorrow morning and, by my calculations, you have a three hour flight ahead of you, even at your speed. Unless you want to fly in the dark, you need to leave now!"

Fluttershy flew up to the roof with Rainbow's packed saddlebags in her mouth. She offered them to her with puppy-dog eyes. Rainbow gave up her battle with the wheel and grimaced, absently rubbing the back of her neck.

"Are you sure? What about Carrot Top's broken window? Or the fallen trees in the Mayor's yard? Or —"

"It's okay, Rainbow," said Twilight. "I've got teams working everything. We've got it all covered. So get going already!"

Rainbow flapped in place for a moment, surveying the town. Then she relented with a sigh. She let her pegasus friend drop her bags onto her back, then gave her a mid-air hug. She dropped to the ground and embraced Twilight as well.

"Alright, alright, I'm going," said Rainbow, smiling. "Gonna miss you guys, though."

"We'll miss you, too, Rainbow. See you in two weeks!"

The loyal pegasus zipped around town to say goodbyes to Rarity, Applejack, and Pinkie Pie. She also went ahead and gave Pinkie her first letter, as a show of good faith that, this time, she really would write every day. Pinkie gave her an extra-long, extra-tight, extra-suffocating hug before letting her zip off into the blue, a faint dot on the horizon in less a minute.

The cleanup continued until Luna's first stars appeared. Everypony went to their beds that night a little sore and a little grumpy.

Sassaflash and Caramel didn't even get to have their date.

The proprietor and resident of the Carousel Boutique dress shop would never consider herself a morning pony. She fervently believed in the value of beauty sleep, a concept entirely lost on her friends. Morning for her was something to get acclimatized to, like climbing a particularly high mountain. This was especially true that Tuesday morning, when Rarity groggily came back to the world of the living with her sleep mask on, not fully recovered from shifting around all that dirty, icky debris the day before. Her natural inclination would be to roll over and return to her dreams of lycra and silk, but she fought it, knowing that she'd have to make up for lost time if she wanted to finish that big order for Hoity Toity before the weekend. The new summer line couldn't wait.

With a small, ladylike groan, she daintily crawled out of bed. Reluctantly, she magicked off her sleep mask, keeping her eyes closed for a moment before letting the painful sunlight intrude on her sensitive retinas.

When she opened them, she felt a brief wave of disorientation. The morning light seemed even brighter than usual. Brighter than it should have been.

"Ugh. What time is it?" she asked nopony in particular. She saw Opal curled up and still snoozing on the comforter. At the same time, she saw the clock on the opposite wall. It was nearly 10 am.

Rarity really ought to have found something peculiar about this, but for the moment, she dismissed the strange sensation as sleepiness. She levitated her bathrobe from its hook and draped it over her back, then stepped her front hooves into her slippers.

That queasy feeling returned as she descended the stairs. She couldn't help but notice that she could see both the bannister on her left and the framed pictures of herself, Sweetie Belle, and her parents, on the right. At the same time.

"I really must have been working too hard," she felt obliged to say out loud, though she wasn't entirely convincing herself.

The kitchen felt even brighter, causing her to squint as she set about putting on a pot of coffee and turning on the stove to fix some oatmeal. Every time she turned her head -- this way to magic the pan over to her, that way to fetch the wooden spoon -- the world rolled and swung back and forth in an unfamiliar way. She began to wonder in earnest if she was ill. Oh no, not today! she thought. I simply don't have time for this. It would be a nightmare if I can't finish those charmeuse gowns.

For some reason she couldn't quite put her hoof on, she didn't trust herself to make oatmeal, and thought perhaps just some fruit would be better. Sure enough, she found half a grapefruit waiting in her fridge.

I wonder if I caught something from Sweetie Belle, she wondered as she scooped out and ate bits of the sweet fruit with the spoon she floated. Or one of her friends. Or one of her classmates at school. That one colt always has a runny nose. If I come down with the flu now and I fall behind on my work, my whole career could be ruined! It would the...worst...possible...

"Ow!" she cried. The grapefruit had rudely spat its acidic juice into her eye. By instinct, she squinted it shut.

And when she did, Rarity couldn't help but notice that she still had two eyes open. Her stomach sank with abrupt terror. She hesitated, and then galloped into the showroom and looked into one of the full-length mirrors.

Located right above her snout, below her horn, and between her eyes, was a third blue eye.

On any other day, anypony within half a mile would have heard her high-pitched scream and rushed to her aid. But today, many other ponies couldn't hear her scream over their own.

Applejack overslept the rooster, which caused her no small amount of frustration. She fumbled with the ribbons as she hastily tied up her mane and tail. She yanked her Stetson off its hook as she emerged from her bedroom. Sure enough, Big Macintosh's room was empty, so he must have already gone out to the east orchard and started the repairs on the fence without her.

She raised a hoof to knock on Apple Bloom's door to rouse the dozing filly, then decided to leave her be. Apple Bloom and her fellow Crusaders had worked just as hard at cleaning up the town as the grownups did. They were probably motivated by a chance to earn civic-duty cutie marks, or something like that, but in any case, Applejack's little sister deserved a sleep-in.

Applejack swept through the kitchen just fast enough to gobble down a couple of warm biscuits from the counter, and bolted out the front door before Granny Smith could scold her for not sitting down to a proper breakfast.

She galloped along the path through Sweet Apple Acres. Not necessarily because she wanted to hurry; sometimes she just liked to feel the rush of the apple-scented air as she ran between the trees. She found it invigorating. Of course, she also felt a slight pang of guilt at making Big Mac work on that fence by himself.

As she crested the top of a hill, she slowed down to a trot. Then her ears perked up at the sound of a strange voice in the distance. It was oddly familiar, but high and squeaky. Applejack wondered who was talking to Big Mac, and why they were talking non-stop about apparently nothing at all.

“Wowee, look at all those apples!” said the voice. “That’s a lot of apples! And all these trees! Lots of trees! Big trees, little trees, skinny trees, fat trees, trees with squirrels in 'em. Squirrels sure are funny looking. Look at those big teeth! If I was a squirrel I’d go to a dentist and see if they could shrink because they sure look funny.”

And on an on the voice droned. Applejack would’ve been sure it was Pinkie Pie, had not the voice sounded male. A male who had sucked the helium out of a balloon at one of Pinkie’s parties. But when she reached the top of the hill, she saw only Big Mac next to the fractured fence. His tools were scattered around him, but instead of doing repairs, he was lying on his belly covering his ears.

The tiny voice nattered on.

“Gee, what’s wrong with that fence? It looks like something heavy fell on it. What was it? A tree? A cow? A cart? A whale? Who knows? Why do they call it a fence? If there was just one fencepost, would they call it a ‘fent’?” And so on.

What the hay? wondered Applejack.

Concerned that Big Mac might be hurt, she galloped the rest of the way down the hill. She took a breath to ask him if he was alright, then stopped short. She looked around to find the pony or whoever it was that wouldn’t shut up.

Just when she was beginning to wonder if she and her brother were being pranked, she spotted the source of the voice, and her jaw dropped.

Big Mac’s cutie mark, a cross-section of a green apple, had a wedge-shaped mouth on one side, which was opening and closing rapidly. It was talking, and Applejack could now recognize the voice as Big Mac’s own, if it were pitched up three octaves and lacked the Apple family drawl.

“Well, hi there,” said the cutie mark. “Who are you? You’re a little pony! Or littler than this big red pony! Or maybe this pony is big and you’re just normal. I don’t know, I haven’t met a lot of ponies. Say, why do they call it a fence?”

Big Mac looked up at his sister, wild-eyed, his lip trembling.

“Help me!” he whimpered quietly.

Applejack said nothing for a few seconds, just trying to comprehend what she was seeing. Finally, she said:

“Applejack!”

“What’s an applejack?” asked the cutie mark. “Isn’t that like hard cider or something? Because I don’t think I can drink any.”

“Applejack,” said Applejack. Then she wondered why she said her name again. She cleared her throat and tried again. What she wanted to say was, “Big Mac! Are ya okay? Why’s yer cutie mark talkin’?”

However, what she said was, “Applejack! Applejack AJ Applejack? Applejack AJ Applejack Applejack Applejack?”

The already horrified stallion gawked at his sister. She clapped a hoof over her mouth.

“I don’t know what you’re saying, lady,” said the cutie mark, “but you sure like to say it a lot! Can’t you say anything else?”

“Applejack! Applejack AJ AJ Applejack!” shouted Applejack.

“No, I guess you can’t. That’s too bad, there are so many more fun words you can say!”

“APPLEJACK!” she bellowed, her voice rising in panic. “AAAAPLEJAAAAACK!!”

It was no use. No matter how she concentrated, her lips, tongue, teeth, and vocal cords all conspired to change everything she said into “Applejack.”

“Wow, you sure are loud, lady!” chortled the animated cutie mark.

“What’s goin’ on with you?” moaned Big Mac. “What’s goin’ on with me?”

“Applejack Applejack, Applejack?” she said, intending to ask, “Wait here, okay?” She stomped with frustration, then galloped back towards the barn-house.

About that same time, Granny Smith hummed to herself in the kitchen as she mashed up fresh honeycrisp apples in a mixing bowl in preparation for a new batch of apple fritters.

A loud clomp reverberated through the ceiling above, making the mounted lanterns sway. Granny nearly dropped the bowl. She frowned at the ceiling. Apple Bloom’s room was directly above. What was that filly up to? And it was about time she had gotten up.

She shook her head and resumed mixing.

A moment later, the house shook again with a series of several clomping noises, which moved from side to side. This time Granny did drop the bowl.

She gritted her teeth as she wiped sticky apple bits off her face with her kerchief. She trotted over to the stairs, and called up to her granddaughter.

“Apple Bloom!” is what she had intended to shout.

But for some reason, it came out as:

“Granny Smith!”

Wait, that ain’t right, she thought. Must be slippin’ in my ripe age.

She tried again:

“Granny Smith! Granny...Smith?”

While she puzzled this out, more heavy thuds came from upstairs. Apple Bloom’s door creaked open.

“Granny?” came a scared little voice. “Somethin’s real wrong here!”

Granny rushed upstairs as fast as her saggy old hip would allow. When she reached the landing, she saw what was real wrong with the poor dear.

Apple Bloom stood in the hallway a foot and a half taller than normal. That was because her hooves now resembled elephant feet. With visible effort, she lifted one foreleg and waved the bulbous extremity around, which was now as big around as a cart wheel. Unable to keep it raised, she let it fall back to the floor with a jarring thump!

Twin streams of tears ran from her eyes.

“Granny Smith!” cried Granny Smith in shock.

They heard hoofbeats on the porch and the screen door creak open and slam. A moment later, Applejack ran up the stairs. Before she could tell them about Big Mac’s predicament, she saw her weeping sister’s hooves.

“Applejack!” she screamed, pointing at Apple Bloom.

“Granny Smith!” exclaimed Granny to Applejack.

“That’s not funny!” sobbed Apple Bloom. She stomped in frustration, a sound of thunder on the creaking floorboards.

“Granny,” said Granny, sympathetically.

“Applejack,” added Applejack.

“Granny Granny Granny Smith?” asked Granny.

Applejack nodded her head sadly.

“Applejack.”

There was still a CLOSED sign hanging in the window of Sugarcube Corner. Not that any customers were expected that day.

In her garret room above the shop, Pinkie Pie examined the newest addition to her face in her bureau mirror. Her snout had become elongated, like a little pink elephant’s trunk, but with tiny pig-like nostrils and a tubular mouth. She opened her more conventional mouth and stuck out her tongue. The smaller, newer mouth opened as well, and another tongue stuck out of it, this one serpentine and nearly a foot long.

There was only one logical course of action when faced with a situation like this.

She squinted in concentration, and curled her big tongue upwards and her snaky tongue downwards. And touched them together. Now she knew what her tongue tasted like! Both her tongues!

Pinkie bounced in horrormusement.

She tried to make her new mouth talk, too, but when she said, “Peter Pony picked a peck of pickles, peppers, pistachios, parsley, and pajamas” ten times really fast, only her boring old big mouth said it. Her boring mouth frowned in momentary disappointment. Though she was frightdelighted that her voice sounded so nasally.

She trotted halfway down the stairs to the shop to see if things were still super-crazy there. They were. She sighed, sticking her head through the bannister posts and watching the spectacle.

“Oh dear, oh dear, oh dear,” whimpered Mrs. Cake, as she rocked poor Pound Cake in her hooves. The pegasus foal bawled. He couldn’t understand why he couldn’t fly anymore. You couldn’t blame him for being upset, though. Any adult pony would probably cry, too, if he woke up to discover that he was now a penguin. His parents could only recognize him by the tuft of brown fur on top of his otherwise feathered head.

Meanwhile, in the kitchen, his twin sister Pumpkin sat on the floor and laughed and clapped at the antics of the three carrot cakes on Mr. Cake’s flank. They’d been telling Pumpkin an endless stream of knock-knock jokes and singing silly songs about pastry. For the past two hours. Mr. Cake leaned dejectedly against the counter and at a loss.

“Knock-knock!” squeaked the carrot cake at the top, a wedge on one side forming a mouth.

“Who’s there?” asked the other two, with enthusiasm.

“Croissant!”

“Croissant who?”

“Gesundheit!”

“Whaaa ha ha ha ha ha!” the cutie-cakes bellowed. Pumpkin fell on her back, laughing as only a baby pony could.

Pinkie Pie covered her lower mouth and snorted. She hadn’t heard that one before.

Rarity arrived at the front door of the library. She wore a silk robe with a hood, a pair of amethyst-encrusted shades, and a grimace. No one had taken much notice of her on the way over, thank goodness. They all seemed preoccupied with their own abnormalities. Though she did bump into the walls of several buildings. Having 50% more eyes made wearing shades designed for the usual number a bad idea. The bridge of the glasses blinded her center eye, and the lenses only covered half of the outer eyes; the resulting bright-dark combination confused her.

She looked around furtively, then rapped on the door.

It swung open to reveal Spike. He smiled broadly at her, out of habit, then sighed and stepped aside.

“Hey, Rarity. Come in and join the party.”

Her friends turned and greeted her as she entered. Pinkie leaped in front of her.

“Hiya, Rarity!” beamed Pinkie, a tongue protruding out of her nose and waving hello.

Rarity yelped and jumped backwards, bumping into Fluttershy. Rarity’s shades clattered to the floor.

“Oh, excuse me, I’m sorry!” said Fluttershy, her face obscured by her flowing mane. Rarity turned towards her, with three wide eyes. Fluttershy screamed, and flinched, tossing her mane to one side and exposing her own, elongated nose and its long tongue. Rarity screamed back, then put a hoof to her forehead and started to faint. Applejack rushed over and caught Rarity on her back.

“Applejack! Applejack?” said Applejack.

Fluttershy screamed again. Pinkie joined in and screamed even louder at nothing or nopony in particular. Screaming was fun!

“Applejack!” shouted Applejack at her.

“WILL YOU GUYS JUST CALM DOWN!”

The library fell silent. All four of them turned their heads to face a stern-looking Twilight Sparkle. She glared at them from behind a levitating open book. The eyepatch that “future Twilight” had worn was slung awkwardly around her head, covering her middle eye. A rubber band clamped the mouth at the end of her tubular nose shut.

Spike made tea for everyone. Pinkie had brought a box of eclairs. They sat on pillows in a circle and partook of the treats. Twilight’s teacup remained cold and full, her eclair untouched, as she rifled through an endless succession of leather-bound books, moving them as she did from one tall stack to another.

“I’ve been at this all morning,” said Twilight, “and so far I haven’t found anything that would explain these...phenomena.”

“It looks like everypony in town has been affected,” said Rarity, dabbing the corners of her mouth with a napkin. Pinkie had conjured up another eyepatch for her to wear. Rarity had asked if they came in any color besides black, then grudgingly covered her superfluous middle eye with the unfashionable thing.

“What about Spikey?” chirped Pinkie. “He seems okay.”

“Spike!” Twilight called out to the dragon in the next room. “Are you feeling any ill effects yet?”

“I’ve got the Parasprite Polka stuck in my head,” Spike called back. “Does that count?”

Twilight rolled her eyes. The extra one did, too, beneath the eyepatch.

Pinkie Pie suddenly had an accordion in her hooves.

“You mean the one that goes like this?”

She succeeded in playing the first six notes before Rarity magicked the accordion roughly away from her and tossed it across the room.

“No!” warned Rarity and Twilight.

“Applejack!” warned Applejack.

“So whatever this is, it doesn’t affect dragons,” said Twilight.

“Or animals, either,” said Fluttershy. “Angel and my other little friends seemed fine. Though they were pretty scared of me with...you know...my nose. And...and...” Tears welled up in her eyes. Rarity put a foreleg across her back.

“What is it, darling?”

“Oh...the ants!” she weeped. “The poor, poor ants! I didn’t mean to do it! I was outside checking on my chickens when I found the ant colony and...and...oh, the poor things...” Even as she blubbered, the long tongue protruding from her nose waved about, as if it had heard somepony talking about ants and wanted some more. Rarity stroked her back soothingly, though she turned her eyes away from the wagging tongue.

“So I guess it only affects ponies,” said Twilight, rubbing her chin.

“Applejack Applejack Applejack, Applejack Applejack?”

The others stared blankly at the orange mare. She stomped a hoof, looked around the room, went to the desk in the corner and returned with quill and parchment. Her friends waited patiently as Applejack carefully scrawled a message out with the quill in her teeth. Then she held it up to Twilight.

POISON JOKE? it said.

“Applejack?” she asked.

“I considered that possibility, but I don’t think so.” Twilight floated over a copy of Supernaturals from a distant shelf and opened it on the floor in front of her. She magically flipped to the relevant pages, and pointed to an illustration of the infamous blue flower.

“When we were all infected by the poison joke, I noticed that some of us had characteristic blue spots on the affected areas of the body. Like on my horn —"

“Twilight Flopple!” giggled Pinkie.

"...or Pinkie’s tongue.”

Pinkie stuck both of hers out.

“The rest of us didn’t have obvious spots like them, but I’d bet that there were spots on, say, Fluttershy’s vocal cords...” Fluttershy put a hoof up to her throat and cringed. “Or maybe on Applejack’s pituitary gland.”

“Applejack!” said Applejack with a curled lip and a shudder.

“Since then, I’ve come up with a spell that would make these spots glow wherever they are. And as far as I can tell...” Twilight’s horn glowed. Her purple aura shone around herself and each of her friends. After a moment, it faded without apparent results. “Nothing shows up. Also, when poison joke afflicts a pony, the effects of the...well, joke...are uniquely tailored for the victim. But as I’m sure you’ve noticed, some of us have the same symptoms.”

“That’s true,” said Rarity. “You and I both have, ugh, extra eyes, Twilight. And you, Pinkie, and Fluttershy all have anteater noses.”

“Aardvark,” said Fluttershy, quietly.

“Pardon?”

“They’re aardvark snouts.” Fluttershy wiped her eyes, her former ant-munching trauma now forgotten. “See, anteater snouts are much longer than this, and they’re smoother, and the nostrils have slits and are higher up.” She pointed to Pinkie’s protruding pink proboscis. Pinkie sat quite still, happy to play Figure 1. “But this snout is more blunt and bumpy, with pig-like nostrils at the end. Aardvark means ‘earth-pig.’ So, um...aardvark snouts.”

Pinkie clapped.

“Right...so, anyway,” continued Rarity, “Three of us have aardvark snouts. But poor Applejack can only say her name.”

"Applejack," sighed Applejack. Rarity tsked and gave her a pat on the back.

“Alright, so what other symptoms have you all observed?”

Pinkie raised a hoof. Twilight sighed and called on her.

Pinkie proceeded to tell them all about her morning at Sugarcube Corner, going into a little too much detail about how long she played with her two tongues before she got around to mentioning Mr. Cake’s joke-telling cutie mark and Pound Cake’s new life as a penguin. She finished her story with a harrowing account of how Mrs. Cake had to smear margarine on Pinkie’s head so she could squeeze it out of the bannister.

Halfway through this epic, Applejack had started to write frantically on another sheet of paper, then scratched out what she wrote and instead drew three more stick-ponies. One showed a little pony with a bow on her head and grossly enlarged hooves. Another showed a big pony with an apple cutie mark; extending from the apple was a speech bubble that read, “BLAH BLAH BLAH.” A third pony with a bun in her mane had her own speech bubble: “GRANNY SMITH GRANNY SMITH.”

“Oh, um, and on my way here,” offered Fluttershy, “I saw Lyra and Bon Bon.”

“Lyra, quit it!” shouted Bon Bon nasally, her aardvark tongue flailing.

“I can’t help it,” said Lyra with her mouth full. “I didn’t eat any breakfast this morning.”

As the two of them walked to the hospital, Lyra had been grazing on the plush lawn of grass, weeds, and flowers that grew from Bon Bon’s coat. The unicorn swallowed, hesitated, then leaned over to take another bite of the dandelions sprouting from her friend’s side.

“Ouch! Watch it!” cried Bon Bon in pain, leaping to one side. The thick porcupine quills that Lyra woke up with had pricked Bon Bon yet again.

“Sorry!” Lyra jerked backwards, and then wobbled unsteadily, unaccustomed to the weight of the huge minotaur horns which curled up from her temples.

The grassy aardvark earth pony and three-horned porcupine unicorn walked on miserably.

Twilight scribbled notes as fast as she could, with arrows connecting the various victims to their mutations. As with previous crazy events that occurred in Ponyville, she would be fascinated with these phenomena if she weren't so worried. It was the scientist in her.

“I need to collect more data before I can get to the bottom of this weirdness.”

As the five of them trotted down the road, Twilight could faintly hear a voice from an overhead cloud. It was happily singing to the tune of “Winter Wrap-Up.”

Derpy Der-py, Derpy Der-pyyy,

Derpy Derp Derp Derp!

Derpy Derpy Ditzy Do!

Not surprisingly, the waiting room at Ponyville Hospital was overcrowded. A sea of morose faces met Twilight’s as she and her friends waded up to the reception desk. Most of the mutated patients slumped down on the floor. No one spoke, except for the inane chattering of a few cutie marks.

“Hey, watch it!”

Fluttershy had stepped on Diamond Tiara’s tail. The filly glowered at her with three eyes, and her porcupine quills raised up aggressively.

“Oh dear! I’m so sorry!” yelped Fluttershy. She turned to apologize to Diamond’s father who sat nearby, but she lost the power of speech when Filthy Rich shook his head at her with his glistening, dagger-sharp canine teeth.

Nurse Redheart looked up at them as they approached, her eyes bloodshot, her nurse’s cap askew, her aardvark snout drooping.

“Hello, girls,” the weary nurse said, sliding a clipboard over to Twilight. “If you would write your names on the list, we’ll get to you all as soon as we can, but I’m afraid the wait will be at least two hours.”

Rarity knelt by a sad-looking penguin with a tiny hourglass cutie mark. She patted the penguin’s head.

“Oh, Colgate, darling, whatever has happened to you?”

“I’m over here.” The voice came from across the room. Rarity turned and saw Colgate sulking in a corner. Her head, legs, and tail poked out of a rustling bush of grass and porcupine quills.

“That’s Doctor Whooves,” said Colgate, pointing to the flightless bird.

“Actually, I was wondering if I could help,” said Twilight to the nurse. “I’ve been cataloging all of the mutations, in hopes of finding a pattern that would help us discover their cause.” She spread out her notes on the desk.

"Oh, thank you, Twilight. We need all the help we can get.”

Nurse Redheart removed the stack of forms from the clipboard. Twilight divided up the sheets and gave some of them to each of her friends. Then they split up and explored theh hospital, finding each patient and writing down their symptoms. At some point, Pinkie starting wearing a doctor’s lab coat and a reflector on her head. She also attempted to write with her aardvark tongue, but she kept dropping the pen.

An hour later, they met up again in the cafeteria and compared notes.

“So far, I can identify ten different mutations,” said Twilight, shuffling papers around the table with her magic.

“The aardvark snout seems to be very popular,” noted Rarity.

“Yeah! And it’s the most fun one, too!” said Pinky, scratching her ear with her mutant tongue.

“Applejack!” said Applejack, intending to say, “Eww!”

“Hmm. Mayor Mare had one,” mused Twilight.

“Roseluck had one, too,” offered Nurse Redheart. “Along with giant hooves. The poor mare."

“So some mutations are more common than others,” said Twilight. “After aardvark snouts, it looks like extra eyes and, er, ‘name-talking’ are prominent, too. Other conditions like growing grass or porcupine quills, or having talking cutie marks or minotaur horns, seem somewhat less common. And sabreteeth is pretty rare.” Fluttershy shuddered at this last one.

Applejack had been scribbling a note. She held it up:

WHAT'S THE CAUSE?

“I...don’t know. Yet. It’s so...weird!” Twilight’s voice was rising steadily. “And why do some of us have two mutations! Why am I lucky enough to have a bonus eyeball and an insectivorous nose? It makes no sense! Rrrrgh!” Her horn flared, and all the papers flew up into the air and scattered.

Fluttershy scooted over and touched Twilight’s shoulder.

“It’s okay, Twilight. You’ll figure it out. You always do.”

Twilight smiled weakly and leaned onto the pegasus’ side.

A tense silence hung over them. Rarity stood up and decided to break it.

“Would you ladies excuse me? I need to powder my nose.”

“It would take me and Twilight and Fluttershy a lot longer to powder our noses,” giggled Pinkie.

Nurse Redheart pointed to the corridor. “Third door on your right.”

As she emerged from the mare’s room, she heard a familiar squeaky laugh, joined by two other juvenile ones. She followed the sound to the open doorway of Room 12.

“Rarity!”

The unicorn rushed over to the bed and hugged her little sister.

“Sweetie Belle! Oh, Celestia, in all the commotion, I almost forgot about you. Are you alright?”

“She’s fine, Rarity,” said Scootaloo, perched on a nearby chair.

“Yeah, she’s doin’ alright!” added Apple Bloom, sitting on the floor. “Well, 'cept for, you know...”

Rarity released the filly and examined her. Sweetie Belle beamed back with three green puppy-dog eyes. Her white aardvark snout twitched back and forth adorably.

“Oooh! Can I have an eyepatch, too?” said Sweetie Belle.

Scootaloo was trying to balance a tongue depressor on the end of her aardvark snout.

“Hey, you both have three eyes! That must be because you’re sisters!”

Rarity jumped at the loud clomping noise as Apple Bloom marched her mammoth hooves over to the orange pegasus. She wore a stethoscope around her neck, which dragged on the cold floor.

“That cain’t be right! Applejack doesn’t have big hooves like me, and neither does Big Mac!”

While Rarity followed this pint-sized exchange, Sweetie Belle hopped off the bed and explored the ajar cabinet. Cutie Mark Crusaders are, by necessity, a curious sort.

Scootaloo scratched her head.

“Well...maybe it’s because they’re unicorn sisters!”

“Nah, no good.” Apple Bloom shook her head, trying to press the stethoscope to her chest with her teeth, unable to grip it with a fetlock. “I saw what’s-her-name, the one who likes to get extra helpin’s of cider at our stand every year...?”

“Pinkie Pie?” guessed Sweetie Belle, as she rooted around the cabinet behind Rarity.

“No, no, the other one.”

“Berry Punch?” ventured Rarity, hoping to move this conversation along.

“Yep, that’s her! Anyway, she’s got three eyes, too, an’ she’s an earth pony.”

Scootaloo dropped the tongue depressor again and sighed.

“Well, how would I know! I’m not a doctor!”

“But I am! Look at me!” They all turned to Sweetie Belle, who wore a facemask, surgeon’s cap, and green scrubs that she practically swam in. She held her hooves upright, as if she had just washed them.

“I’m ready to operate!” she said in a dramatic voice. “I need ten see-sees of something-something, stat!”

All three fillies laughed hysterically, Scootaloo rolling onto her back, Apple Bloom thumping the floor with a deafening bang! Rarity wasn’t amused.

“That’s enough!” she said, pulling the depressor and the stethoscope away with her magic and returning them to the cabinet.

“These aren’t toys! You’re in a hospital, for pete’s sake!”

“Sheesh! What’re you so grumpy about?” said Dr. Sweetie Belle.

“I am not grumpy. I am just tired. It has been a long day. Now take that off!”

“Okay, okay, fine,” grumbled Sweetie Belle as she took off the mask and surgeon’s cap. Rarity pulled the scrubs over her head, then neatly folded them and put everything back in the cabinet.

“Honestly, Sweetie Belle, what am I going to do with you! And just look at you!”

“What?”

“You’re a mess.” Indeed, the surgeon’s cap had left her mane rather unruly, sticking out in some places, smooshed flat in others.

“Hold still,” Rarity said through gritted teeth, as she tried to fix the filly’s mane with her hooves and magic, wishing she had a brush—

She froze.

It’s the most amazing feeling, really. What someponies refer to as “a moment of clarity.” It’s like staring at a forest for days and days, and then in a fraction of a second, you blink and the forest magically morphs into...a bunch of trees! It was like walking around not understanding why you’re soaking wet and you turn a corner and suddenly you’re under the shelter of an awning and you can now see that it’s been raining! It was like...staring at a bolt of fabric until you will it into the most fabulous wedding gown to grace the halls of Canterlot!

It was also like falling really, really fast while standing in all four hooves. Which is why Rarity felt dizzy for the second time that Tuesday.

“Rarity? Are you okay?” asked Sweetie Belle from very far away.

Without answering, Rarity shot out of the room and down the corridor.

Back in the cafeteria, Twilight scanned the crumpled notes endlessly. She even flipped up her eyepatch in the dim hope that the central eye might help her find something. Nurse Redheart had to return to the front desk. Fluttershy and Applejack listlessly played tic-tac-toe, and Pinkie was trying to bend her upper tongue into a heart shape.

All of them stopped at the sound of a rapidly approaching pony.

Rarity swooped in like a wingless Wonderbolt. She skidded to a stop, panting.

“I’ve...got it!”

“Got what?” asked Fluttershy.

“The connection!” Rarity grabbed her fellow unicorn by the shoulders. “We’ve been so blind, Twilight! Even with extra eyes!”

All of them gawked at her without comprehension. She stood up on her hind legs and spread her forelegs wide, entering drama mode.

“It’s all so clear! Don’t you see?”

Awkward pause.

“See what?” said Twilight.

“Close your eyes! All of you.” Her friends looked puzzled, then complied.

“Now I want you to imagine the ponies that I name.”

They nodded. Pinkie grinned. This is gonna be fun!

“Applejack.” Rarity paused for dramatic effect. “Lily.” Another pause. “Cherry Berry. They’re all name-talkers...and what else?” She watched her blind friends’ faces contort with concentration. But no light bulbs apparently lit.

“They’re all...earth ponies?” said Fluttershy.

“No, no, no. Try again. Now think...Carrot Cake...Big Macintosh...Snips...All of their cutie marks are talking...aaaaand?”

Rarity could hear her own heart thumping in the painfully long subsequent pause. Applejack just shook her head. Fluttershy’s bottom lip trembled in frustration.

Twilight’s trio of eyes snapped open. She turned towards Rarity and nodded, smiling wide. Rarity giggled with glee.

“Rarity! You’re a genius!” Twilight beamed. “May I?” Rarity graciously yielded the floor to her.

“Okay, girls...Fluttershy...Pinkie Pie...and a little bit...me.”

“We’re...all friends?” tried Fluttershy.

Applejack opened her eyes and scribbled: “ELEMENTS OF HARMONY?”

“We all have dreams where we’re eating a waffle cone the size of a mountain and rainbows shoot out of our ears?”

Twilight and Rarity facehoofed in stereo. Fluttershy turned to Pinkie.

“How did you know that?”

“Hair color!” bellowed the unicorns together.

Lightbulbs lit up above pony heads all around.

“Applejack?” asked Applejack, pointing to her mane.

“Yes! That’s it!” cried Twilight, giddy as a schoolfilly. “Ponies with similar mane and tail colors have the same mutations!" Fluttershy and Pinkie pulled their pink manes in front of their eyes, then looked at each others’ aardvark snouts.

The purple in my hair is causing my extra eye.” Twilight ran a hoof through her tail, as if she’d never seen it before. “And I have this pink stripe to thank for my nose!” She gasped and broke into a gallop out of the room. “Follow me! And I need hair samples from each of you!”

Twenty minutes later, Twilight peered at a strand of Applejack’s blonde mane hair through a microscope, while the others paced around the hospital’s research lab. A thought occurred to the hair’s owner, and she wrote it down on a chalkboard:

MAYOR MARE? SHE’S GOT WHITE HAIR AND HAS ~~ARD~~ ~~AARDEV~~ A FUNNY NOSE

“That’s right!” said Fluttershy. “I thought white hair caused porcupine quills?”

“And what about your grandma?” Pinkie asked Applejack. “She can only say her name. She doesn’t have quills either!” Rarity considered this a moment, and then she laughed.

“Girls, don’t you remember the dirt that ‘Gabby Gums’ dug up on the Mayor? Her hair isn’t naturally white! She dyes it!”

“Oh yeah!” said Pinkie, giving Fluttershy a squeeze. “The Mayor’s a pink-head like us!”

Applejack chuckled and slapped her forehead with her own revelation. She wrote:

GRANNY WAS BLONDE AT MY AGE

“So it has to do with our real hair color,” said Fluttershy, extracting herself from Pinkie.

“And now I know why!” declared Twilight, triumphantly. “Take a look at this!”

She took a moment to remember a certain spell. Then her horn glowed, and so did the microscope. A moment later, a beam of purple light projected from the lens of the instrument. They all looked up at the image which appeared on the ceiling: a close-up of Applejack’s hair magnified by several orders.

At first, they weren’t sure what they were looking at. Then something moved.

“Applejack?”

Twilight adjusted the instrument, and it zoomed in even further.

A little yellow insect-like creature with glowing antennae crawled up the side of the follicle and bit down on it.

Rarity screamed and fainted with a thud. Fluttershy fanned her with a wing.

“I’ve seen these things before in one of my books on magical microscopic zoology. They’re called tetramites. They’re a kind of parasite.”

“And it’s living in our hair?” said Pinkie. “Eww!”

“Fascinating,” said an awed Fluttershy, absently flapping, bereft of the horror the others felt.

Twilight switched the slides under the microscope, replacing Applejack’s sample with Rarity’s. In the projected image, just as with the blonde hair, another tetramite clung and gobbled at the violet follicle. This one glowed violet.

“They must feed on pony hair,” continued Twilight, in her element. (Not magic, her other element: lecturing.) “Here’s my theory: tetramites feed on the keratin in our hair follicles, but I think it probably prefers long, thick hair. Our coat hair is too short. Now the mane and tail hair of equestrian ponies has some unique properties...”

Twilight went on like this for the next seven minutes, using words like “chromatic follicular melanogenesis,” which caused a chain of yawns among her friends. The short version: pony hair contains a unique blend of red, yellow, and blue pigments, which, depending on their relative quantities, can produce virtually any color. And while these chemicals are cake, pie, and muffins to tetramites, they’re also allergic to them. Their feasting causes a magical aura to form around them, which in turn, affects the genetic makeup of the pony’s cells. Different combinations of pigments cause different reactions, which manifest themselves in the various mutations.

“A creature with these magical properties must have come from the same place you’d find poison joke!”

“The Everfree Forest!” gasped Fluttershy.

“Exactly! That big windstorm yesterday must have blown all these little devils right out of the trees they call home in the Everfree...and blew them all over Ponyville!”

“Ugh!” Pinkie stuck out her tongues. “So the whole time we were outside cleaning up after the storm, the air must have been full of these hungry little bugs!"

Somewhere in the middle of all this, Rarity regained consciousness, refusing to turn her three eyes to the garish image on the ceiling again.

“So does that mean that there’s a cure?” she asked. Twilight beamed.

“Yes! And I’ll need your help with that, Rarity, along with your friends at the spa!”

“What can we do?”

“We need...to make shampoo!”

Another awkward pause.

“Makes sense to me!” said Pinkie.

“I have some natural ingredients in my lab that I guarantee will put a bad taste in these tetramites’ mouths! We’ll just mix them with shampoo, and everypony will just wash the mutations away!”

“YAYYY!” they all cheered, jubilant, jumping up and down. A nurse with minotaur horns poked her head in the doorway.

“Shhhhh!”

“Yay,” they cheered again, much more quietly.

“To the spa, everypony!” A wonderful thing for Rarity to say. They made their way out of the hospital, the sky beginning to redden with the sinking sun.

“I’ll just stop by home and -- oh...NO!” Twilight’s aardvark tongue waggled in horror.

“What?” “What’s wrong?” “Applejack?” “What is it?”

“Girls, we’re gonna need to work fast! Fluttershy, find Cherry Berry and tell her to get the balloon ready! We’ve got to make a quick batch of the shampoo and then we’ve got to go!” This last she called back over her shoulder as she galloped off.

“Why?” called Rarity. “Where are we going?”

“CIRRUCUSE!”

Many hours later and many miles away, pegasi in Wonderbolt gear had gathered around the door to the infirmary. Spitfire, resplendent in her blue drill uniform, stood in a pool of light from the lamp above the door. Her scowl concealed the abject terror she felt inside. She’d performed many death-defying feats over the years, but never, ever, had her courage failed her like it did that night.

Hoofbeats clomped rapidly on the adjacent tarmac. Spitfire tipped her shades with a shaky hoof. The cadets parted to let a party of five ponies though. Spitfire recognized them immediately.

“Ms. Sparkle! Halt!”

Twilight gasped for breath. Then she pointed at the infirmary.

“Is she...?” she croaked.

“There’s a pony in there, alright, but we’re not sure it’s even her anymore.”

“Let me see her!” Twilight stepped forward but Spitfire blocked her path.

“No! You can’t go in! It’s...horrible! We’ve never seen anything like it!”

Several of the cadets whimpered.

“It’s okay, I know how to help her!” Desperate times, desperate measures. Twilight lifted the captain off her hooves in a purple aura and moved her aside, dropping her with a thud.

“So, so sorry!” She boldly flung the door open with her magic and entered the infirmary. Spitfire got to her feet and followed her in.

“Wait!”

The dimly-lit quonset hut was deserted, except for two ponies.

One of them was a pegasus stallion clad in a long black coat and a fedora, brandishing a glass bottle marked “HOLY WATER.”

The other was an unfortunate Rainbow Dash.

Equestria’s fastest flier circled around wildly, bouncing off the walls and careening against support posts, and flopping onto one of the beds. Her three eyes bulged, her blue body obscured by a coat of grass in serious need of mowing, her demonic black horns scraping against the walls, her freakishly swollen hooves thumping against the floor with an unholy racket. And apparently speaking in tongues:

“Rainbow Dash! Rainbow Rainbow Dashie Dash Rainbow Dash! RD, Rainbow Dash!”

The determined stallion, his black coat billowing behind him from the gusts of Rainbow’s thrashing, vigorously shook the bottle at the possessed pony, sprinkling water in her monstrous face. He roared at the eldritch abomination before him:

“The power of Celestia compels you! The power of Celestia compels you! The power --”

Twilight magically took the bottle from his hoof.

“Thank you ever so much, sir,” she said, “but I’ll take it from here.” She levitated into view a travel-size plastic shampoo bottle and calmly strolled up to Rainbow. The exorcist just stood there, dumbstruck, his coat no longer billowing.

Rainbow spotted the Element of Magic and alighted on the floor.

“Rainbow?” asked Rainbow, a ray of hope in her eyes. Twilight hugged her. Rainbow couldn’t hug back with the weight of her hooves. She nuzzled back happily instead.

“Hi, Rainbow Dash,” said Twilight, leading her confused, over-mutated friend into the night. “I think you’re in need of a nice long shower.”

“Dun dun dunnnn!” said the thundercloud on Rainbow’s flank.