Rarity beamed at her reflection, the long hours of preparing herself for the day showing obvious results. She trotted through the hall and down the stairs, magically cleansing imperceptible (to all but her) specs of dust as she went, taking her time reaching the front of her store. Feeling abnormally beatific in lite of nothing going obviously wrong, and the assurance that later it absolutely would and that she could scratch her drama itch when it did, she flipped her sign from 'Closed' to 'Open'.
BOOM.
Well that was fast, said her subconscious as Rarity shrieked and leapt backwards, a pegasus blasting through her window with improbable force and crashing amid the dresses of a display. Rarity took a calming breath and got to her feet, rather upset with herself for having somehow failed to summon her fainting couch. She composed herself for a moment, re-affirming her coif, before taking an enormous breath and letting it loose with a vengeance, "RAINBOW DASH, YOU ABSOLUTE-"
She was still deciding what exactly she could get away with calling Rainbow when the pegasus' head popped out of the wreckage of the display and her outrage petered out in the face of the genuinely unexpected, "Fluttershy? What-? Why-?"
She turned back to the window, whose shutters hung limply from rattled hinges, "...How?"
The yellow pegasus staggered to her feet, panting in exertion and clearly not adjusted to Rainbow's level of bodily-inflicted property damage, "Rarity... You've got... you've gotta..." She stumbled forward against Rarity, face planting into her barrel, "You've got a reeeally soft coat."
The white unicorn squinted at her dazed friend nuzzling her coat, the context of the situation leaving her uncharacteristically at a loss for words, "Um... thank you?"
Fluttershy shook herself, frantically seizing Rarity by the shoulders, "You've gotta come quick! Twilight and Pinkie got into an argument about who between them holds the record for longest single breath and it got reallyheatedandTwilightsaidshewouldcastavacuumspelloverthemandtheywouldbothwaitinsideitandthefirstonetopassoutwouldbetheloserandIthinkshemightactuallydoitandyou'vegottacomequicksoyoucantalkthemoutofit!"
Rarity blinked, resting a calming hoof on the shoulder of the hyperventilating pegasus, "Calm down darling, verbose one-breath explanations don't suite you. What's this about Pinkie and Twilight?"
Rarity burst into the Castle, Fluttershy in tow, ready to talk some sense into Pinkie and Twilight.
However, it appeared that she was not the first pony Fluttershy had reached out to. In fact, if her headcount at a glance was correct, she may very well be the last ponyvillian to arrive in the great hall. The enormous space was PACKED with town ponies. The Crusaders, Raindrops, Big Mac, Cherilee, Snips and Snails... even Mayor Mare was peering over the crowds.
Rarity gawked at the spectacle, "Fluttershy what...?"
The pink-maned pegasus scuffed a hoof and blushed, "I, um, may have been a little frantic and got anyone I could find."
"So you really just got whomever and I happened to be one of them?" Rarity deadpanned into the distance, all heroic momentum lost.
"W-w-w-w-well..."
"Fluttershy! Rare!" Rarity turned to see a stetson waving near the front of the gathered town ponies.
Grumbling, Rarity began to shoulder her way through the crowd, eventually stumbling free of the mass and into Applejack, "There ya are, thought you weren't comin'."
Rarity's disgruntled reply died on her lips as she got her first look at the spectacle before them. Pinkie Pie and Twilight Sparkle sat, unmoving, eyes locked with one another, inside a faintly shimmering barrier at the base of the steps leading to the throne.
Taking in the scene for a moment, Rarity swallowed, "Are they...?"
"Hard vacuum." She glanced down to find Spike, reclining in a fold out chair and munching on popcorn.
"Isn't that...?"
"Totally lethal? Sure is."
"And how long...?"
Rainbow Dash buzzed them, ruffling Rarity's hair, "We're coming up on the 20 minute mark! I mean, I'm used to Pinkie's craziness but this is on a whole other level, even for her! And Twilight!?" She deflated a little bit, "Well. She's probably got some magic hold breath spell or something."
"Nope." Spike held up a metal rod inscribed with runes, "She's clean, she had me check both of them before she put the shield up."
Rainbow squeed with excitement, "This has gotta be a world record!" She frowned at Rarity, "You really took your time getting-"
"I KNOW." She glared at Fluttershy, who, having finally nudged and apologized her way through the crowd, caught her eye and immediately tried to nudge and apologize her way back in. Rarity huffed, turning back to the standoff, "I assure you, it wasn't my fault."
Rainbow circled back, hovering above them as was her wont, "Ah, cut Shy some slack, she's not a trained speedster. I'd have gotten you myself but, hay, I wasn't gonna miss out on this!"
Just-barely-metaphorical steam escaped Rarity's ears as AJ patted her on the back, "Don't worry 'bout it Rare, yer here now. Ah was here 'fore they even started, Twi explained the whole thing ta me. Either of them passes out, the spell drops, and the air goes back in."
"That hardly seems to-" Rarity interrupted herself, sputtering, "Wait, you LET them do this!?"
AJ groaned, "Well Ah tried ta talk 'em out of it but you know how Twi gets when she thinks she can, or should, win a competition. And of course Pinkie-"
Rarity threw up her hoof, "Nevermind, I get it, but could someone please explain to me how this is possible? Doesn't vacuum make you explode or something?"
"Well actually," Spike began, "based on Twilight's experiments, you wouldn't so much explode as you would dehydrate, since there's no air pressure to stop the water from boiling away. So it would probably just make you bleed from every..." He trailed off, scratching his chin, "...Huh. How are they doing that?"
"Well, Twilight Sparkle is an Alicorn-" Rarity's eyes widened as Princess Luna spoke up, rising from where she'd been examining the magical glyphs surrounding the bubble, "-and as such, she is able to-"
"Hold her breath for a very long time. Isn't that right? Luna." Celestia (Celestia!?), gave her sister a hard look as she enunciated her words.
Luna scoffed, "Oh come now sister, they know I was on the moon, tis' not a secret there was no air."
"Would you keep your voice down Luna?" She hissed in response, "I don't want to have yet more of my freedoms curtailed because you can't resist handing out our secrets like candy every time anyone asks."
"Oh come on, you can't blame me for everything ms. 'I'm sure nobody would poison my morning tea, nobody's that evil'."
The sisters continued to bicker but Rarity paid them little heed, as reclining next to them on what was unmistakably HER fainting couch was-
"DISCORD!? Are you KIDDING ME!? FLUTTERSHY!"
Fluttershy had wisely retreated back into the congregated ponies, invisible save for the occasional glimpse of pink through the legs of the crowd. Discord peered at Rarity over his sunglasses, unimpressed by her outburst, "Hey, it's pretty impressive she was able to get all these ponies here in just 20 minutes, don't you think? Count yourself lucky she got you at all, you're not exactly known for 'solving the drama'." His air quotes were so heavy that Rarity swore she could almost feel them in her head, but of course that was ridiculous.
"YOU GIVE THAT BACK!" She snatched the fainting couch from under the draconequus in an unprecedented display of strength, inadvertently swatting Rainbow out of the air with the magical furniture. Discord remained unmoved by her outburst, continuing to float midair as if his support hadn't vanished, blinking his drink and glasses out of existence with a snap of his fingers.
"Anyway, we've all been having a grand old time asking each other 'how is this possible?' but I think what we should really be doing is..." He vanished in a puff of smoke, reappearing amid the crowd, wearing a green visor and leaning out of a booth with a giant neon, "$$$" sign, "PLLLLLACE YOUR BETS LADIES AND GENTLECOLTS, PLACE YOUR BETS! No telling how much longer the NEWBORN ALICORN will last against the APRICOT PARRRRRRADOX!"
The crowd gasped and pony's began flocking to the booth as Rarity, fuming, tucked the couch safely back into hammerspace where it belonged, "She's. Not. Even. Apricot!"
"Still-" RD was airborne and out of earshot before Rarity could hear the rest of what she said, slipping into the rapidly forming line with a sack of bits in hoof.
The former diarchs eyed the stand with expressions of tolerant amusement, Celestia speaking quietly to her sister in an offhand tone, "It does seem rather gauche to bet on such a trivial thing..."
Luna turned to regard her sister, eyebrows raised as she waited for her to continue, "But...?"
"Hypothetically, if we were to-"
Luna rolled her eyes in exasperation, "No, sister, we are not putting money on your student winning a bet that she, Literally. Can't. Lose."
"Oh fine." The solar princess turned back to the contest, face bearing the most regal of pouts, "I suppose it would be unsporting."
"I don't know, my money's on Pinkie!" said Pinkie, handing Spike a fresh box of popcorn while munching on her own.
Rarity turned to face her flamboyant friend.
Luna peered over her head.
Celestia frowned over Luna's horn.
Spike stopped mid-munch, swiveling in his chair to regard the pink earth pony with the others.
Rarity cleared her throat, "Pinkie?"
"Yeah?"
"Why are you here?"
"To watch the show of course! Duh!"
"Yes, yes, but: why are you out here? You're supposed to be facing off against Twilight in the bubble. You ARE facing off against Twilight in the bubble."
"Oh yeah..." Pinkie raised a hoof to tap her chin, "shoot, I knew I forgot something."
The crowd started to notice that there were two pinkies in attendance, and the excited bustle soon gave way to confused murmurings. Discord discreetly pocketed the bitpurse Rainbow had just handed him and vanished in a puff of smoke. Twilight glanced away from the still intently glaring Pinkie across from her, the sudden stillness no doubt drawing her attention. Silence reigned the hall for a long moment.
Celestia brought a hoof to her mouth, chuckling, "Well. That explains that."
Luna squinted between the two pink ponies, "Does it though? Why did she have a perfect replica of herself ready for this? How did we not notice her until just now? And how did she trick us all into believing it was... Sister?"
Celestia's smile had faded and she was staring at the shimmering bubble containing the befuddled Twilight and Pinkie's facsimile, "Applejack?"
The farmer perked up, "Yer highness?"
"What did you say were the exact conditions Twilight set to lower the spell?"
AJ scuffed her hoof, "Uh... Well, Twi said a lot a magic science stuff about blood oxygen levels and physol- phsiolo... point being, she said when either her or Pinkie started to pass out in the bubble, the spell would drop." She finished.
Rarity frowned, "But if Pinkie is out here... and Twilight can't... Oh dear."