…filling me larger and larger with blueberry juice. I’m not sure just how big I got by the end. And now I’m almost out of paper, so I’ll have to tell you how I escaped and what friendship lessons I learned in my next letter.

Your faithful student,

Twilight Sparkle

Twilight quickly proofread her letter. Normally, she would ask Spike to transcribe her friendship reports, but she wasn’t ready yet to share the contents of this letter with him. Remembering the events of that trip to the forest—and that strange, vexing zebra she’d met there—still brought a blush to Twilight’s face. So she reread the letter herself to make sure it was absolutely ready to send to Celestia, glancing at the kitchen door every few seconds as she triple- and quadruple-checked the most important parts of her narrative.

She was alone in the central room of the Golden Oak Library. Surrounded by the bookshelves of her new home, the inviting scent of tree sap and printed pages, and the warm morning sunlight through the windows, Twilight couldn’t help but feel an overwhelming sense of safety—as if the events in the letter had happened in another lifetime, to another pony. She barely shivered as she reread, for the fifth time, the parts about her own inflation and Zecora’s butt.

Finally satisfied, she rolled the letter into a scroll and called, “Hey, Spike!”

Spike poked his head out of the kitchen. “Yes, Twilight? Do you have a letter for me to write?”

Twilight waved her scroll in the air. “I wrote up this week’s Friendship Report myself. I just need you to send it.”

“What about that spellbook from your research shelf? Wasn’t there a spell to let you send letters to Celestia yourself?”

“That’s right!” Twilight turned back to the table, where a large book was open to her latest topic of study: a theoretical spell that would let her unicorn magic behave like Spike’s dragonfire. “This would be a perfect time to test it.”

She glanced between the spell and the scroll, then turned back around. “Are you sure you’re okay with this, Spike? I’d hate to take away your job…”

“Come on…” Spike trotted into the room. “I’m your number one assistant—don’t worry! No spell could ever replace me.” Spike was a bit taller than Twilight remembered. But that was to be expected—he was a baby dragon, after all, and still had years left to keep growing.

“Alright, then.” Twilight held up the scroll, visualized the spell in her mind, then cast. The magic turned green in mid-air before it enveloped the scroll. Seconds later, the paper was consumed, leaving a trail of smoke curling lazily in the air.

“Yes, Twilight!” Spike cried, leaping in the air. “You got it right!”

Then the smoke moved—but not towards the open window facing Canterlot. It instead raced directly towards Twilight’s face. Her eyes widened, but before she could do anything else, the smoke rushed into her mouth and directly down her throat. It settled inside her chest, puffing out her barrel like she had taken a deep breath—but strangely enough, it didn’t hamper her breathing or even make her cough.

“That didn’t work,” Twilight said, then groaned.

“Try again, you’ll figure it out.” Spike said, holding up a blank sheet of paper. “You’ll ace this spell, without a doubt!”

“Okay…” Twilight took the page, then scribbled a quick note explaining to Celestia that this was just a test, and the proper Friendship Report would be arriving soon. This time, she made absolutely certain that every component of the spell was perfect before she cast it. Once more, her magic turned into green fire and consumed the paper.

And once more, the smoke rushed down Twilight’s throat, inflating her torso a few inches more.

“Urrgh…” Twilight glanced at her puffed-out barrel. It felt like she had a volleyball in there somewhere—and it looked that way, too.

But she would not be deterred. She studied the spell in the book again to make sure she hadn’t forgotten anything, then grabbed another sheet of paper from the stack next to the book and cast the spell once again.

“No need for alarm,” Spike cheered her on. “Once more! Third time’s the charm!”

But the third puff of smoke just followed the first two, straight into Twilight’s mouth. This time, she felt it settling not just in her chest, but in her backside as well; a glance back confirmed that her haunches were rounder and a few inches wider than before. But they weren’t as wide as her barrel, which had gained a foot in diameter by this point.

Twilight sighed. “Spike? Can you try it? Maybe if I watch you, I can see what I’m doing wrong.”

“If that’s how you feel. Sure, no big deal.” Spike grabbed two sheets of paper from the stack and breathed a quick flame over both. A double-sized puff of smoke rose into the air and curled around itself.

And then that smoke rushed into Twilight’s mouth. Her rump grew several inches more, her barrel expanded until it brushed against the insides of her legs, and even her legs thickened a couple inches.

“Spike!” Twilight cried. “What did you do?!”

“Huh? I didn’t do anything new. Sent the letter to Princess Celestia, like I always do.”

“But it didn’t go to Princess Celestia this time. It went into me!”

“I don’t know what you’re talking about, Twilight. Here, let me show you again—just hang tight…” Spike grabbed more paper from the stack, this time three pages.

“No!” Twilight shouted, reaching one foreleg towards Spike, squeaking slightly from the motion.

Dragonfire engulfed the three pages, and the smoke wasted no time before rushing into Twilight, filling her even larger. Her legs swelled to twice their normal width. Her torso bulged between them, forcing her legs to spread as it inflated further. And her rump expanded until both cheeks were the size of beach balls.

“There. Straight to Canterlot, see?” Spike said with a smug grin on his face. “Now if you don’t need me for anything else, I hear some comic books calling for me…”

“Fine…” Twilight said. She made her way back the table and her spellbook, but slowly and awkwardly. Her puffed-up legs were much stiffer than normal, while her swollen barrel pushed back against her limbs with every step she took. Her body squeaked with every motion as her legs rubbed against her inflated belly and her rump cheeks rubbed against each other. Eventually she reached the table and lifted the thick book in her telekinesis. She started to read…

“Don’t worry, Twilight, I’m sure you’ll get it right!” Spike punctuated this with a playful slap on Twilight’s rump.

“Eeep!” Twilight started, partly from sheer surprise and partly from how her inflated cheeks amplified the sensation of the slap. (She could almost swear it felt more like an adult pony’s hoof than a baby dragon’s hand.) On pure reflex, magic surged into her horn: the same spell she had cast three times in the last few minutes.

“Oh, no,” Twilight said, as the ersatz dragonfire washed over the thick spellbook. Smoke already rose from the flames and sped towards her. She clamped her mouth shut, but the smoke went into her nose instead. Closing her eyes, she scrunched her muzzle to keep her mouth tightly shut—which wasn’t easy, because the smoke tickled inside her nostrils as it slid down. More slowly than before, her barrel and behind ballooned one inch, then two. Her back rounded out, while less than a foot separated her swollen belly from the floor. Twilight snorted, trying in vain to push back the smoke invading her nostrils, gradually inflating her larger. Her legs thickened even as they spread to accommodate her swelling torso—her puffy hooves squeaking as they slid across the floor.

Then a tendril of smoke crept up Twilight’s face and tickled her right ear. That proved too much. Twilight opened her mouth to give an involuntary giggle, and then the clouds of smoke rushed in: filling her cheeks, forcing her jaws wide open as they poured down her throat, expanding her faster than ever. Her barrel puffed out until it squished against the floor—and then it was the only thing touching the floor, as her swollen legs stuck straight out, inflated too stiff to bend anymore. Resting on her smoke-stuffed belly, Twilight was actually taller than before, and she grew taller by the second as her torso bloated larger and larger. Her rump, twice as wide as before and still growing, now reached higher than her head.

Finally, the spellbook was gone, and the last of the smoke disappeared into Twilight’s swollen, rounded body. Her torso was an ellipsoid, over twice her usual height; her backside was a pair of cheeks the size of exercise balls. Her legs were thick balloons, squeaking as Twilight tried to move them and found they could only waggle a few inches.

Suddenly, there came a cough from the corner of the room. Spike, seated in his favorite reading nook, looked up from his comic book before coughing again—the distinct cough that signalled he was getting a letter from Princess Celestia! The smoke wafted out his mouth, but instead of hovering in front of his face like usual, it sped over to Twilight.

As the smoke of the inbound letter curled in the air before her face, Twilight said, “Huh. That’s odd. It—”

Then that smoke rushed into Twilight’s mouth, adding another inch to her already-enormous girth.

“Spike! What was that?!” Twilight called out. She waggled her legs frantically, squeaking up a storm. “Why did Princess Celestia’s letter do that?!”

“The letter was pretty short. Celestia’s probably wondering about your Friendship Report.” Spike put aside his reading material and trotted back towards Twilight. He walked on all fours now, and even in that stance he stood tall as an adult pony. Twilight couldn’t help but wonder how she hadn’t noticed him growing that much.

“Yes,” Twilight said, “but…”

Spike coughed once more—another letter arriving from the Princess. And this one sped down Twilight’s throat, as well, joining its brother inside her bloated barrel.

“I can’t blame Celestia for writing to you,” Spike added. “Your Friendship Report is pretty overdue.”

“Oh, no…” Twilight gulped. “I’m tardy?”

As if in answer to her question, another letter from Canterlot arrived and rushed into Twilight, inflating her another inch.

“I’ve got to finish this! Explain everything to Princess Celestia! Surely, she’ll understand…” Twilight telekinetically reached for her quill and another sheet of paper—in her hurry, forgetting that she had no way to get this message to Celestia quickly enough.

As she set the quill and to paper with her her magic, the aura around both suddenly turned to green flames, without any prompting from Twilight. “No!” Twilight cried. “No, no, no!” Desperate to quench the dragonfire, Twilight beat the paper and quill against the nearest surface—which was the stack of other papers. Quickly enough, the magic flame spread to that stack. Twilight’s ears folded back as she gazed up to the top of the stack; it towered over even Twilight’s inflated body, reaching into the cloud of smoke that already obscured the ceiling. This smoke wasn’t just from the stack of paper: every few seconds, another letter arrived from Princess Celestia, adding to the cloudy mass.

As the first puffs of smoke sped towards Twilight, she didn’t even resist this time. She just opened her mouth and let the smoke fill her even further. Her cheeks puffed up as large as melons, while each of her rump cheeks inflated as large as she herself had been, and then even larger. Her whole body quivered and squeaked as she swelled farther. And the squeaking was loudest at the base of her legs: her forearms and haunches inflated twice as thick as her already-puffed-out cannons and hooves, and they began slowly merging with her expanding barrel. Thicker and rounder her torso grew, nearly three times her normal height now. But as large as Twilight inflated, the top of that burning paper stack didn’t seem to draw any closer…

“Look what I found, Twilight!” Spike trotted in front of her, balancing hundreds of scrolls on his back: a stack taller than himself. “All these old Friendship Reports we forgot to send her. No wonder Celestia is so worried! I just hope we didn’t offend her.”

Twilight groaned, her voice slightly muffled by the mass of smoke still pumping down her throat. How had she let those forgotten letters pile up like this? She’d be in so much trouble…

“If I hadn’t noticed, these would’ve stayed in that corner forever.” Spike said. “I should send them now! Better late than never.”

Twilight’s eyes widened. “Nnnnggh!” she shouted against the flow of smoke. She reached out with her magic, pulling the stack of scrolls away from Spike before he could unwittingly add it to the mass inflating her.

Then her magic spontaneously turned into dragonfire again, setting all the scrolls ablaze anyway. Twilight whimpered, gulping down more smoke and ballooning larger all the while.

“Whoa!” Spike recoiled from the burning mass of scrolls, then bumped into Twilight. He squished into her huge, round side with a loud squeak, then both bounced away from the collision. Twilight spun in the center of the room; Spike stumbled towards the wall, where he bumped against a very plush couch, large enough to seat three ponies. And as Spike fell, he sneezed—setting the couch ablaze with his green flame. The smoke rose up, joining the dark cloud that obscured the ceiling, just waiting to fill Twilight even larger.

“Hhhhmmmm…” Twilight moaned as she spun and spun, inflating to four times her height and even higher.

Spike rose to his feet, then glanced between Twilight and the scorched spot on the floor where the couch had stood. “Oh, that reminds me! Today’s the day when Celestia’s sending all the books and furniture you left behind in your Canterlot castle spire. She’s teleporting them by dragonfire!”

“Mrrrhhm! Mmnnnnn!” Twilight shook her puffy legs helplessly. She continued rotating, and the smoke pumped her larger still.

Spike gave a small cough—and somehow produced a huge puff of smoke. “Ah, that looks like your encyclopedia’s volume one. Only a hundred forty-nine more to go before you’re done!” He coughed once again, producing an even larger cloud. “And there’s volume two! When Celestia’s done with the encyclopedia, she can send the rest of the library to you!”

Twilight shook her head as she rose even higher atop her inflating torso. This didn’t halt the flow of smoke down her throat; the tentacle-like cloud clung to her face like it was a living, solid thing. Then it spread over her muzzle and poured into her nose again, adding to the flow already passing through her mouth. Two more tendrils crept up the side of her face, tickling her cheeks until they reached her folded-back ears. Twilight involuntarily flicked them—which was all the opportunity the smoke needed to force its way into her ears and inflate Twilight even faster.

Her torso expanded to six times her normal height, then larger and larger. Her upper legs were round doughnut shapes attached to the enormous balloon of her body, swallowing her limbs up to her elbows and stifles now. Those legs squeaked even louder as Twilight wiggled them more, futilely trying to halt her continued spinning. Her neck thickened and began to merge with the huge curve that had been her shoulders. Her rump cheeks filled up, each as large as her mattress, and then larger still.

“There’s that sci-fi series you never read!” Spike declared. And then he produced a smoke cloud that dwarfed the encyclopedia volumes. “And there’s your old bed!”

As Twilight spun towards the tower of burning paper, she saw an opportunity to make this madness end. She magically created an airtight force-field around the papers, intending to choke off the towering inferno. A few seconds later, the shield turned into green flames, and ersatz dragonfire began consuming the entire table. “Hhhhrrrrrnnn!” Twilight protested as she spun away from the larger fire, inflating all the while.

Though the smoke was pumping into Twilight faster than ever, the cloud overhead wasn’t getting any smaller. Quite the opposite, in fact: the Princess’s deliveries and the fire inside the library were adding to the mass of smoke even more quickly than Twilight’s ballooning body could take it in.

“There’s your second bookcase!” Spike declared as he coughed up another jumbo-sized smoke cloud. “Oof, I can’t keep up this pace.”

As Twilight spun towards Spike, she reached out with her magic once more—desperately hoping that forcing her Number One Assistant’s mouth shut would somehow stop the deliveries from Princess Celestia. Instead, when she clamped his muzzle shut, Spike’s face popped off his head and hovered in Twilight’s telekinetic grip. It was just a cheap paper mask.

The face under the mask wasn’t Spike, or any dragon. It was a zebra mare with hypnotic cyan eyes and a haughty smirk on her beautiful lips. What had looked before like purple and green scales were now obviously just a costume—patterned spandex, or some similarly stretchy fabric that clung tightly to her body, leaving none of her shapely curves to the imagination. It covered from her hooves to her tail to her neck, leaving only her pretty face exposed.

And then, with a demure little cough, Zecora produced another enormous cloud of smoke. “That’d be your wardrobe, and some spare clothes,” she said, flashing a wicked smile at Twilight, just before the ballooning unicorn spun away. “It felt like a lot—rows upon rows!”

Twilight whimpered, inflating over nine times her old height. The forgotten paper mask, still hovering in her magic, smiled back at her mockingly—then burst into green flame. Its smoke drifted into the mass overhead, just another drop in the ocean steadily filling her even larger. But Twilight wasn’t sure how many more drops she could take. Her cheeks were puffed up, each as large as her own head, and they brushed against her inflated neck as it merged with her torso. Her expanding barrel engulfed her legs even farther: just six inches from her pasterns, now. Her rump, each cheek thick enough to fill a walk-in closet, was merging with the huge globe of her body. Her cutie marks were stretched to the size of bedsheets across her inflating haunches.

Out of sight, Zecora chanted, “She’s an enchantress quite smokey. She’s gonna burn down this oak-y…”

And somehow, Twilight continued spinning. Instead of losing momentum, she spun even faster than before; the walls of the library seemed to rush by too fast for her to focus on any details. Twilight used her telekinesis on herself, pushing against her rotation. But the magic aura just slid off the huge curve of her body and down to the floor, creating a circle of green flames in the rugs and the wood beneath them.

Twilight cast a stabilizing spell on herself, hoping that would hold her in place. It just bounced off her rubbery sides and struck a few dozen random books in their shelves, setting them all ablaze with more dragonfire.

Twilight cast her general failsafe spell. It exploded, scattering green fire over all the library’s walls.

“Spreading flames to make gas, on which you will choke-y…”

“Nnnnrrrrrrrr…” Twilight groaned as she spun even faster. The walls were a blur, dominated by dragonfire-green as the flames spread further and further. The whole room would be ablaze soon enough, and the entire tree after it—reduced to magic smoke that would just fill Twilight even larger. And the dark cloud above was more voluminous than ever, still growing faster than it could force itself into Twilight.

“It’ll fill you to sizes, that you just can’t revoke-y…”

Then she felt something brush against her expanding barrel, all along its widest circumference. Twilight had inflated to twelve times her height, and wide enough to touch the library walls. Her swelling sides squeaked as they slid along the polished wood and the bookshelves; the tickling sensation seemed to echo inside her massive volume. Then, with one final squeak, she stopped spinning—ballooned large enough to wedge herself in place within those walls.

Twilight lay dazed for a few seconds, her eyeballs spinning in their sockets—and she took in more smoke all the while, bloating larger and larger. Her belly pressed tighter against the floor, expanding to fill the corners of the room. She would have spread over the furniture, if there were any pieces that hadn’t already burnt to smoke.

“Cause you’ll burst like a bubble, if you touch anything pokey!”

When Twilight’s eyes stopped spinning, she found herself facing the front door—the only wall her ballooning torso hadn’t covered yet. More dragonfire licked across this wall; already, there were burnt holes large enough to see the outside through. And in front of it stood Zecora, still wearing her Spike costume, gazing up at Twilight’s immensity with an unusual expression—not the haughtiness the inflating unicorn had come to expect from her tormentor, but something softer. Zecora stepped forward and put one spandex-clad hoof to that inflating purple belly, almost caressing Twilight as she expanded even further.

Zecora said, “...So try not to croak-y.”

Then with a snort, she turned away, slapping Twilight’s side with her costume tail. Twilight’s face lit up at the sensation—and the squeak her belly gave in response, and the way it shook her huge globe of a body. Then she scowled and began pouring magic into her horn.

This was all Zecora’s fault, Twilight thought, and if she could just apprehend that pesky zebra, then all of this could be undone… somehow.

She fired an impenetrable force-field spell at Zecora. But the zebra dodged to the side without even looking back. Twilight’s spell struck the wall instead, instantly reducing half of it to smoke. And Zecora just strolled out that hole with a little extra bounce in her step—which in turn added a little extra bounce to her backside. Once again, her form-fitting costume left nothing to the imagination. Twilight shot off another force-field—straight at the perky, spandex-clad zebra rump—but Zecora sidestepped that shot just as easily. The magic bounced off the ground and struck a tree across the street, setting it ablaze with dragonfire—producing still more smoke to fill Twilight even larger.

And then Twilight’s inflating belly spread over what was left of the front wall, covering that hole and blocking all view of Zecora. Seconds later, her back squished against the ceiling. Inflating further, Twilight filled every corner and crevice of the room—her face pressing against the wall while her bloating torso squeezed into every doorway, every window, and every hole burnt by the fire. When there was no more space left for Twilight to expand into, she just kept inflating anyway; the flame-weakened walls cracked and bent outwards from the pressure of her unrelenting growth.

Zecora, standing outside the Golden Oak, could see the library wouldn’t last much longer. Green fire danced through the canopy, its smoke swirling into a dark cloud just a few feet above the highest branches. The trunk bulged outwards, and a ballooning purple unicorn’s sides squeezed out of every new crack that formed.

Inside, Twilight grimaced, screwing both eyes shut as she inflated even further. Her face was smushed between the wall on one side, and her own body swelling over every other side. Even that didn’t stop more smoke from rushing into her—and as her body stretched farther to contain it all, her skin grew increasingly sensitive. The walls and ceiling pressed back against her endless expansion, then cracked or bent, then pressed back again; the touch of the wood all over felt like Zecora’s caress, amplified a hundredfold. But where her body bulged against jagged cracks—where countless splinters poked into her expanding sides—she felt a persistent stinging. And the caresses and stings were spread all over Twilight’s huge balloon of a body, so she couldn’t tell where the pain ended and the pleasure began.

Twilight moaned, sucking down a few more cubic yards of smoke. The tree gave one last creeeeeeeeak of defeat, then exploded. Branches, splinters, and other debris—all of it on fire—either shot into the air or bounced off the side of the huge purple balloon emerging from the wreckage.

“Mmmrrrrrr…” Twilight moaned, inflating even taller than the library had been. She was more a gargantuan globe than a pony now, with just her head, tail, and hooves protruding from her nearly spherical torso. And still she ballooned even larger. The cloud of smoke, still filling Twilight, was just a little smaller than she was. And the still-flaming debris from the library continued feeding that cloud—and spread the dragonfire to three nearby houses, creating yet more smoke to expand Twilight even further.

In spite of the destruction, there were no screams of fear, no panicky ponies running through the streets—not even any gawkers. Ponyville was deserted, aside from Zecora and Twilight. Stranger still, the sky had grown dark. Beyond the mass that continued inflating Twilight, clouds of even blacker smoke hung over all of Ponyville.

Zecora pointed up at the sky. “That dragon you shooed off with dear Fluttershy—he’s gone but his smoke still fills the sky! Somepony must clear it, and do so right now.” She flashed a smug grin at Twilight. “And since I’m a dragon, I believe I know how.”

“Hhrrmmrrrrmmm,” Twilight mumbled. She had a pretty good idea what Zecora intended to do, but couldn’t muster the will to fight it anymore.

But Twilight didn’t expect Zecora to leap higher than a mountain goat and land atop a nearby roof. Another leap took the zebra to an even taller housetop, and a third took her to the very top of Sugarcube Corner. From there, Zecora sprang right into the smoke itself—and simply paused at the top of her leap, hovering in midair like a pegasus, or Pinkie Pie.

Zecora opened her mouth and inhaled. She sucked down lungful after lungful of smoke, faster even than Twilight had. Within seconds, her belly inflated large enough to fit another of herself inside, and then two. Her ass tripled and quadrupled in size, bloating disproportionately large, even in comparison to her oversized belly. She took in more and more smoke, expanding over six times her volume before the growth slowed.

Zecora’s costume was pushing back. That purple-and-green spandex had stretched along with her body—embracing her voluminous curves and leaving nothing to the imagination—but it could stretch no longer. Now, the outfit fought to contain the ballooning zebra, but it was a losing fight. One seam along Zecora’s belly was already coming undone, allowing stripes of gray and black to peek through; another seam on her backside followed suit.

Zecora screwed her eyes shut and sucked harder, puffing out her cheeks and forcing her body to expand another foot in every direction. More seams tore open, along her torso and rump, and even on her neck and legs—and Zecora’s bloating body bulged through these holes in the trembling spandex, ripping them even farther. With another great breath, she added another foot to her diameter—revealing more of her expanding, stripy body as the costume deteriorated even further. The fabric was shaking all over now, barely staying together under the pressure of holding back her huge, round body.

Scrunching her face, Zecora sucked with all her might, which filled her cheeks as large as pumpkins—and finally broke the costume. The spandex tore to ribbons all over, freeing Zecora to inflate in the blink of an eye to ten times her volume, then twenty times, and then even larger. Her legs puffed out, tripling in thickness and sticking straight out as they filled with smoke. Her now-uncovered rump bounced as it ballooned larger and larger, her cheeks rubbing against each other.

Zecora was as large as a hot air balloon, and still inflating larger—a black-and-gray globe with an ass nearly as enormous. The only color on her round, striped body were bits of purple spandex—scraps of the costume still clinging to her neck, tail, and hooves. Her legs had already sunk halfway into her bloated sides, and were swallowed further as Zecora filled even larger.

The end was in sight for Zecora. More of the sky was clear than smoky by now—and there was more smoke inside her already than left above Ponyville. Sucking in more and more of the remaining smoke, Zecora grew to the size of a two-story house and then even bigger. Her body engulfed her neck with its inflation, then started on her head—squishing her mane flat against her scalp and squeezing the sides of her swollen cheeks. Her sides bulged further over her legs, swallowing them almost to the hooves. Her backside was so huge, the sun sigil on her haunches looked large enough to eclipse the real Sun.

At last, inflated as large as a three-story house, Zecora swallowed the last of the smoke over Ponyville—save for the personal cloud that had kept filling Twilight this whole time, and was still going. In fact, the two equines were roughly the same size now, though they were different shapes: Twilight was nearly spherical and had the larger belly, while Zecora had the larger, thicker rump.

With the sky mostly cleared, Zecora ceased hovering and succumbed to gravity, only to careen off Sugarcube Corner. She bounced from roof to roof, soaring with the lazy grace of a beach ball—right towards Twilight.

“Hrrrmm?” Twilight muttered, as the bloated zebra drew inexorably closer. “Mmmrrrrrrr!” Frantic, she tried to wriggle her legs to move herself out of the way—but her limbs had been swallowed by her torso’s inflation up to the hooftips, and could barely move an inch now.

With one last bounce, Zecora closed the distance to Twilight. Their faces lined up, and Zecora rolled forward, pushing her swollen gray belly into Twilight’s purple sphere—and pressing her lips against Twilight’s as well. Twilight froze for a second, then closed her eyes and pursed her lips to reciprocate. When Zecora prodded gently with her tongue, Twilight opened her mouth to allow her inside.

Zecora exhaled right into Twilight’s mouth. Her breath didn’t smell of dragon smoke, somehow, but something in-between freshly grilled vegetables and a campfire on a brisk fall morning. And she just kept exhaling: the smoke that had inflated Zecora now rushed out her mouth to fill Twilight even larger than she already was. Twilight expanded to twice the Golden Oak Library’s height; her hooves sank completely into her swelling torso with one last squeak, leaving her head and tail as the only remaining evidence she was a pony, not an absurdly huge balloon.

Still, Zecora inflated her even larger. And she wasn’t the only thing filling her: while the zebra hogged Twilight’s mouth, the dark cloud overhead continued pumping smoke into Twilight’s nose and ears. Larger and larger Twilight expanded, swelling with unthinkable volumes of smoke. She ballooned wide enough completely fill the library’s plot of land—for her sides to brush against the houses on either side, and against a stick resting in the road, all that remained of the library’s branches.

Zecora shrank all the while, as every cubic inch she lost was one Twilight gained. And as Twilight’s unicorn shape disappeared further and further into her balloon of a body, Zecora gradually regained her figure. Her belly and backside shrank lazily; her neck slowly emerged from her diminishing torso, as did her legs soon after.

As Zecora’s kiss and the smoke overhead filled Twilight to unthinkable sizes, her gargantuan belly pressed harder against the houses to each side, firmly wedging herself in between. Her girth bulged around the walls and over the roofs. In turn, the corners and eaves dug into her inflating sides; at those spots, a reddish tint showed through her purple coat, then gradually spread as she inflated larger and larger.

Meanwhile, Twilight moaned into Zecora’s mouth, straining to push herself harder into the kiss, heedless of the smoke inflating her beyond all reasonable limits. Zecora’s lips were sweet fire against her own, a pleasant burn that rushed down her spine to the tips of her hooves, sunken somewhere inside her balloon of a body. It spread across every uncountable square inch of her expanding torso—and it intermingled with the sting from the house edges that poked deeper into her bloated sides. The red tint spread further, matching the fire she felt within; where the red deepened, her skin trembled. The deepest crimson was at the point where the stick’s sharp end dug straight into that expanding belly.

As Twilight inflated taller than Ponyville Town Hall, Zecora’s legs deflated enough that she could flex them again. So she reached forward to wrap her forelegs around Twilight’s head—squeezing her hooves between those puffy purple cheeks and the inflated neck and shoulders already trying to engulf the unicorn’s head. With her forehooves running through that purple mane, Zecora could hold Twilight in place to ensure she inhaled every cubic inch of smoke. But that wasn’t strictly necessary: even if Twilight could wriggle away, she was too lost in the kiss to even try.

Louder and longer Twilight moaned, as seemingly endless volumes of smoke filled her to ever greater sizes. The burning as her skin stretched closer to its absolute limits was matched by the heat of Zecora’s lips. The pain of the houses digging several feet into her inflating body—and the sharp stick concentrating similar pressure into a single point—was matched by Zecora’s gentle hooves on the back of her head. Twilight was more red than purple at this point, as she inflated closer and closer to her absolute limit. As her skin stretched further, it vibrated like overtightened violin strings, producing creaks and squeaks all over her gigantic body.

Finally, Zecora forced her last lungful of smoke down Twilight’s throat, just as the last traces of the cloud above disappeared into Twilight’s nose. There was no more smoke, no more burning debris, and no more deliveries from Princess Celestia. And just in time, too—this expansion had stretched Twilight all the way to the brink.

Zecora ended her embrace, pulled away from the kiss, and calmly slid down the pony-balloon’s massive curves, back to the ground. She was light on her hooves, yet Twilight’s drum-taut hide turned a deeper crimson at Zecora’s slightest touch.

Once released from Zecora’s hooves, Twilight’s head sank into own inflated body, leaving only the tip of her muzzle exposed. She was over twice the height of Town Hall, and almost completely unrecognizable as Twilight Sparkle—or even as a pony. The only remainings clues of her true nature were her tail, little more than a speck against her immense frame, and her cutie mark, extended as tall as a house but obscured by her pervasive, overstretched redness. Anypony who saw her—and she was visible from miles away, towering over Ponyville—would have mistaken her for a crimson blimp.

“Ooooooh…” she moaned, having finally regained control of her own mouth. “Oh, Zecora…”

Zecora landed on the street, then gave the massively inflated Twilight a warm smile. But the smile faded at what she saw: a blood-red spot where the sharp stick dug dangerously deep into the unicorn’s inflated belly. It was a miracle that point hadn’t already penetrated Twilight’s skin.

Zecora leaned towards the stick, then paused. This job needed to be done very carefully. The slightest increase in pressure, and that point would pierce right through Twilight’s overstretched body. The slightest move at the wrong angle, and that point could slice the unicorn wide open. Zecora needed to be absolutely precise…

In one swift motion, Zecora reached in, grabbed the stick with her teeth, then pulled it away.

Twilight’s entire body vibrated a little more—her skin intact, but still expanded to the absolute limit.

Zecora sighed and spat out the branch, away from the blimp that had been Twilight. “Great stars above!” she said. “I need to take the utmost care, when my fav’rite balloon’s so tight and full of air!”

When the stick hit the ground, it kicked up a cloud of dust. Then a wayward gust of wind blew the dust right into Zecora’s face. “Aaah… Aaaaah…” she said, rearing her head back. “Achoo!”

Green fire flew from her muzzle as she sneezed. It washed over the stick, consuming it in an instant. The smoke zoomed up to Twilight’s muzzle.

Twilight’s entire blimp of a body shook and creaked. She tried to scream, “MMMMRRRRRRRRRRRRR—”

The explosion could be heard from miles away. The shockwave shattered half the windows in Ponyville. Seconds later, a thick layer of smoke washed over the entire town.

Just as quickly, the smoke departed—flying for Canterlot at the speed of magic.

—————

Princess Celestia, alone in her private study, was reading a very engrossing biography when smoke suddenly poured through the open window. The first mass hovered above her head, but it quickly grew until it covered the room’s whole ceiling.

She said, “What—?”

And then the deluge began. Scrolls, letters, completely blank pages, whole books, bookshelves, couches, tables, beds, rugs, a couple trees’ worth of branches and sticks, and whole houses’ worth of timber and masonry—all fell from the smoke cloud. They completely buried the Princess before she could react, then continued falling until they filled the room six feet deep.

With its payload delivered, the smoke finally dissipated. The room was still.

Two ponies stirred underneath the avalanche. First, Princess Celestia poked her head out of the debris. Shortly after, Twilight Sparkle emerged as well—restored to her normal proportions and color, save for the blush on her cheeks.

The Princess blinked in surprise, before donning her usual warm smile. “Twilight Sparkle, my faithful student, it’s wonderful to see you. But this truly is a surprise. What brings you to Canterlot in this way?”

“Haha, well, it’s kind of a long story,” Twilight replied. “Let’s just say Spike really deserves a bigger allowance.”

Author's Note

Huge thanks to MintyCandy for helping with the rhymes in this chapter. And for illustrating a scene from this chapter. It’s on https://derpibooru.org/ #1457718 and on http://www.furaffinity.net/ #23786380.

Also, Thefurryrailfan did another great illustration. It's on https://derpibooru.org/ #1439451, and on http://www.furaffinity.net/ #23559121.