The sputtering growl of Sunset Shimmer’s motorcycle sounded almost frustrated as she parked it in front of Pinkie Pie’s house and cut the engine.

“Me too, buddy,” she thought to herself.

She couldn’t dismount immediately though, on account of the cute nerd with her arms still wrapped around her waist, not-so-subtly feeling up Sunset’s abs. Twilight had done that the whole ride over after being picked up from her place. In fact, she did it every time she got a ride from Sunset, who didn’t have the heart to tell her she wasn’t nearly as slick as she thought; after all, then she might get self-conscious and stop doing it.

“Hey. Twi. We’re here,” she said.

“Mmhm,” Twilight responded dreamily, and her fingers twitched a little over Sunset’s stomach.

Sunset rolled her eyes affectionately before gently prying Twilight’s hands off. She slid gracefully off her bike, turned to the Pie household, and promptly rolled her eyes again, this time with exasperation. Sunset Shimmer pulled out her phone and dialed.

Ring ring ring.

“Rainbow Dash speaking,” Rainbow Dash spoke.

“Dash, where are you?”

“Uh, I’m at Pinkie’s place, waiting for you. Why?”

“No,” she pinched the bridge of her nose, “No, you’re not. I’m standing right here and it’s just me, Twi, and Pinkie.”

“Hi Dashie!” Pinkie shouted in the general direction of Sunset’s phone.

“What?” a rustling came from the other end of the line as, Sunset imagined, Dash sat up in alarm and confusion, “How’d you get there so fast?”

“Dash, it’s been more than half an hour.”

“Ugh. Fine, I’ll be right there,” Dash groaned, then muttered, “Take me less than a minute to run over anyway…”

“See you soon, Dashie!” Pinkie called out just before Sunset ended the call. The three of them waited in various states of silence – Pinkie’s amiable, Sunset’s annoyed, and Twilight’s slightly awkward and shivering despite the heavy, poofy coat she wore – for several seconds before a multicolored blur resolved itself into a young woman hopping on one foot as she rapidly decelerated from subsonic speeds.

“Alright, I’m here,” Rainbow said as she trudged through the frosty grass of Pinkie Pie’s lawn, “now where’s pony Krampus?”

“Dash, I know you think this is funny, but this is a serious situation. Someone could get really hurt if we don’t find the-“ despite her grave tone, Sunset hesitates and stumbles over her next words, “…creature quickly.”

“Uh, yeah I think it’s funny. It’s hilarious! I’ve seen Pinkie Pie do the Mari Lwyd,” Sunset flinched again at the name, “before, thing’s goofy lookin’. How could it possibly hurt anybody?”

“In fairness to Dash,” Twilight interjected before Sunset had the chance to castigate their friend further, “You didn’t tell us much about it earlier. All you said was that it was ‘pony-eating’, which might not even apply on this side of the portal. Also, can we take this inside? I’m freezing out here.”

The four of them headed inside and up to Pinkie Pie’s room, where the summon circle from her ill-advised ritual still sat undisturbed save for some slight scuffing of the chalk. Dash made a beeline for the jug of cider, uncorked it and gave it a little sniff.

“Hey, Pinkie, you mind if I…?” she asked.

“Not at all!” Pinkie said.

“Dope,” Dash brought the jug to her lips and took a big swig.

“You’re drinking it cold?” Twilight’s face contorted in mild disgust.

Rainbow Dash shrugged.

Sunset, who had frozen in the doorway to Pinkie’s room to stare with shock at the array, said somewhat dazedly, “Pinkie… how-? That… th-this is Equestrian magic – and some seriously advanced stuff, at that. Where did you say you learned this again?”

“Oh, the Pie family grimoire!” Pinkie chirped, producing the tome in question to shove into Sunset’s numbly grasping fingers. She looked down at it with a look of great consternation, so Pinkie helpfully opened it for her. Her eyes widened and she flipped rapidly through the pages, open jaw falling ever wider with each ritual, spell, or concoction she saw. Rainbow Dash slurped noisily from her cider and Sunset shook herself free of her reverie.

“You know what? This is a problem for later,” she said, tossing the grimoire onto Pinkie’s bed, “Okay. Walk me through what happened when you summoned… it.”

Sunset brought a hand to her chin as Pinkie energetically explained the immediate aftermath of her summoning, nodding along to each point.

“Well… it could be worse. Honestly, its behavior is kind of encouraging, all things considered.”

“Is it?

“I mean, yeah, it didn’t immediately try to eat Pinkie. That’s a win in my book.”

“Okay…” Twilight rubbed at her eyes beneath her glasses, “Sunset, if we’re going to deal with this situation we need to know as much as possible up front. You have to tell us everything you know about the Mari Lwyd from your world.”

“I know, I know, you’re right. Hoo boy… okay, so I’ve told you girls about Hearth’s Warming and its origins before, right?”

“With those windy ghost things?” Rainbow said.

“Poltergusts, yes. The legend goes back to the second ever Hearth’s Warming, the year after Clover the Clever, Smart Cookie, and Private Pansy’s discovery of the fire of friendship. The holiday caught on pretty quick since it was the main thing keeping wintry Armageddon at bay, but Star Swirl the Bearded-” and here Dash and Twilight both gave groans of annoyance, “- yeah, yeah, I know - Star Swirl was worried about it not being enough. He had the idea to create a magical construct to spread festive cheer, really try and get everypony’s spirits up and make the fire even stronger than it had been the year before.”

“And lemme guess: he screwed up big time?” Rainbow Dash’s guess was not so much hazarded as sanctified and reinforced.

“Well, it… kind of worked? See, the legend goes that the Mari Lwyd’s primary drive is in fact to foster Hearth’s Warming Cheer, to act as an anti-poltergust measure, it’s just that somehow Star Swirl made it to think the best way of doing that was less friendly mascot and more… Holiday Inquistion.”

“Oh no…” Twilight buried her face in her hands, “Please don’t tell me this is going where I think it is…”

“Yyyyeah,” Sunset grimaced as she continued, “anypony who wasn’t up to its strict standard of merriment… it tried to eat them.”

Twilight, Pinkie, and Rainbow looked at her in gobsmacked silence.

“Wow. Why did anyone ever think this idiot was super smart, again?” Rainbow remarked.

“And he didn’t think to, I don’t know, destroy it?” Twilight asked exasperatedly.

“I mean obviously he tried, but the best he managed was getting it down to only hunting for one pony a year. It just goes for the biggest humbugger – and no I don’t know how that’s determined – eats them and takes their skull. At any given time the skull it’s wearing actually belonged to its most recent victim.”

“If this didn’t suck so bad that’d be really metal.”

“Okay. So… what do we do about it?” Twilight asked.

“Well, we-“

At that moment, Sunset’s bag started to glow and vibrate in a very familiar way.

“Ooh, looks like you’ve got a message from Pony-Twi, Shimmy!” Pinkie announced unnecessarily.

“Yeah, I wrote her earlier for advice,” Sunset replied as she fished the dimension-spanning two-way diary out, then slightly quieter, “hopefully she has some ideas, because I sure don’t…”

The girls crowded around Sunset on Pinkie’s bed, peering over her shoulders or from her side at a mostly-empty pair of pages. In Sunset’s crisp, clean handwriting, a message read:

TWILIGHT I NEED YOUR HELP PINKIE PIE SUMMONED THE MARI LWYD INTO THE HUMAN WORLD

And just below it in the elegantly flowing script of Equestria’s youngest princess:

SHE WHAT?!

“Heyyyy, that’s what you said, Sunset!” Pinkie observed.

HOW DID SHE EVEN MANAGE THAT?!

I’m not entirely sure, but that’s something to figure out later. What can you tell us about the Mari Lwyd?

A minute, then two and three went by in tense silence.

Just what the legends say, unfortunately. I’ve already started searching through the library for more. I could ask Star Swirl himself too, if you want?

The girls passed hesitant grimaces between each other.

“I mean… it can’t hurt to just ask, right?” Sunset rationalized, transforming the looks on the others faces from hesitancy to skepticism. “And if whatever he tells us is really stupid we can just ignore it and come up with our own plan.”

“Yeah, but on the other hand what if he does help?” Rainbow shuddered, “I’d hate to owe that guy anything.”

“Rainbow, I don’t think now is the best time to be too proud for help,” Twilight said, undercutting herself only slightly when she muttered, “even if it is from an irresponsible old coot…”

Sunset chose to make an executive decision.

Yes, Princess Twilight, please ask Star Swirl what his advice is for this situation.

Just a minute.

Several more tense minutes passed. Sunset imagined Princess Twilight teleporting to wherever their shared once-idol on the other side of the mirror, asking him with that adorable and slightly breathless rushed tone both Twilights fell into in times of stress about the Mari Lwyd. She imagined what the conversation might look like, how long it might take, and scant seconds after she supposed it might end the Princess’ writing materialized once again on the page, rushed and shaky from infuriation.

HE SAYS “GOOD LUCK LMAO”

NOW IF YOU’LL EXCUSE ME I NEED TO GO FIND OUT WHO TAUGHT HIM THAT ACRONYM AND THROTTLE THEM

The girls in the ape dimension looked as one to Pinkie Pie.

“What? I’ve never talked to Star Swirl on any of my trips. Everything I’ve heard makes him sound like a total buzzkill.”

“Okay,” Sunset sighed, tossing the book with a careless disrespect entirely unbefitting of a powerful magical artifact that breached the walls of reality over her shoulder. It landed unceremoniously in a pile of assorted plush animals. “Guess we need to make a plan ourselves. Any ideas?”

“Blast it?” Dash suggested.

“Not sure we can with just the four of us,” Sunset said slightly glumly.

“Plus it probably wouldn’t work anyway!” Pinkie chirped, “The Mari Lwyd isn’t evil, just… overzealous.”

“Unfortunately I have to agree with Pinkie,” Sunset began, “no offense-“

“Mm!” Pinkie made a little noise and shrugged before laying her head down in Sunset’s now-empty lap.

She idly ran a hand through Pinkie’s curls as she continued, “-it’s just that, while I may know more about how magic works back home, that doesn’t mean the rules are any less weird. The Mari Lwyd probably technically qualifies as holiday magic – or else it’s defensive in the same way a guardian statue is. Our harmony beam would either do nothing or, worst case, make it stronger, and we still don’t even know what it’s going to do in this world.”

“Maybe our first move should be to find and observe, then,” Twilight gently wiggled her phone in the air, “I’ve been looking through local news and social media feeds while we were talking and I’ve found several posts which seem to mention it. Extrapolating its path through the city, it appears to be going to Canterlot mall, of all places.”

“Guess that’s where we’re going too, then. One problem, though…” Sunset grimaced, “I’m the only one with a vehicle, and it can only take two, max.”

“Right…” Twilight brought a hand to her mouth in thought, which slightly muffled her next words, “Rainbow Dash can just run there-“

“Damn right.”

“-but between Pinkie and I, someone is going to have to stay behind.”

“Oh, heehee, that’s not an issue at all, sillies! I have just the thing,” Pinkie said, and before Sunset even realized her head was off her lap their energetic friend was already out of the room and down the stairs.

“Uh…”

A few moments later, an extremely soft thunk sounded against the window. After the second thunk, Sunset stood to look outside, and with the third the projectile stuck to the window; a marshmallow, partially eaten.

Sunset opened the window.

“See?!” Pinkie called up from beside Sunset’s bike, “Problem solved!”

In less than a minute, Pinkie had managed to procure a tiny sidecar and attach it to the motorcycle. Its owner cringed at the sight, the bright pink paint job and goofy banana-split patterning rather severely at odds with her usual image. Rarity was rubbing off on her, because she was bothered too by the way it clashed garishly against her bike’s paintjob – image aside, the admittedly somewhat stereotypical flame decals were just plain tacky juxtaposed against the new addition. She forced herself not to think too hard about it, a mental reminder that there were presently bigger fish to fry.

“How long have you had that, Pinkie?” Rainbow Dash called down to her.

“Uh, pretty much since always? Duh?” Pinkie Pie’s confusion at the question was genuine, “Why wouldn’t I have a sidecar?”

“Where was she even keeping it…?” Sunset murmured, mostly to herself.

“What are you three waiting for? Come on down already, we’ve got a holiday beastie to catch!”

Sunset wordlessly pulled the window shut, noting with disgust how the marshmallow Pinkie threw had smeared across the glass when the outer panel pushed against it. Pinkie, meanwhile, strapped a helmet on and climbed into the sidecar, folding her legs up in front of her with a beatific smile gracing her features. It was hard to be exasperated at her for any real amount of time, but her closest friends were giving it the old college try in that moment.

“I should’ve gone home for the holidays,” Sunset Shimmer said as she turned to go hunt herself a hobby horse.

Author's Note

Yes I know "Poltergusts" is not their actual name, no I am not calling them that other thing.

Also, Science Twience's opinions on the temperature of apple cider do not reflect the author's.