The “container” was an airtight plastic pouch, maybe the size of Tera’s hoof, that require something sharp to open. Tera’s prosthetic horn, like the natural ones, didn’t quite have the precision necessary to make a cut by themselves. Which was probably a good thing: if every unicorn suddenly had the power to cut anypony or -one in range to ribbons with their mind, things would go south very quickly. But it meant that Tera needed to grab scissors.
She did, and before continuing, read the instructions one more time. She was to mix the powder in the packet, actually a kind of yeast, with some sort of sugar or starch and a bit of vinegar as an “activation agent”, and the resulting biochemical reaction would create carbon dioxide and methane. Said methane could then be burned. It was an interesting new prospect for renewable energy, and one which was actually fairly well proven. The question was more how to scale it up.
That wasn’t the question on Tera’s mind, though. She just wanted to see it for herself.
She looked in the pathetic assortment of cupboards in her apartment that she called a pantry, and found no vinegar. She double-checked the instructions.
Saw an asterisk.
“Or lemon juice.”
Which meant any acid would work.
So, because any starch and any acid would work, apparently, and (she double-checked) the yeast wasn’t a biohazard, she decided to let her stomach do the work and feel it for herself. So she made a meal of half a dozen packets of instant oatmeal (because she was an adult mare, nopony could stop her from eating oatmeal for lunch) with the yeast on top, then waited.
And waited, for something to happen.
She thought she maybe felt a little something shifting in there, but nothing much, at least not at the moment.
So she decided to busy herself with a favorite toy she had installed in the shower.
She filled herself up to the medium setting, stopped it off with the butt plug she had handy, and went back to the living room to read a book. It was nice, having a day off, and this particular book had been enticing her ever since she’d bought it. It was just called Rods; the hook was that it was about the creation of a fleet of spacecraft (whose shape inspired the title) that could traverse the space between star systems effectively instantly, and about how that one invention breaks basically everything in its universe. Apparently, it involved a lot of political intrigue, and at times it turned into a noir story, and the author somehow worked a romantic plotline into it without making it suck (at least, that’s what the hearsay was), and in general it was that one doorstopper that comes out each year that manages to take the publishing world by storm despite, or maybe because of, its sheer length.
She cracked it open, lowered herself down onto her water-bloated belly, and started reading.
And kept reading, page after page after page.
And all that time failed to notice the results of her previous mistakes.
Tera was impatient, a bit, by nature. So she failed to realize that a bunch of yeast waking up, and multiplying, and doing their work, would take a bit of time, especially if she hadn’t eaten anything and her stomach was at the moment acid-free, or if she did realize it she didn’t care. And so of course she was disappointed.
But then she made her big mistake: she filled herself up with water and then capped it off. Suddenly, all these microorganisms were not only awake, they had a half gallon of oatmeal to feed on and all the real estate they could possibly want. And all their gaseous by-products had nowhere to go.
Night had already fallen when Tera came to the sudden realization that her rear hooves were not touching the floor. She dropped the book and checked the time.
She wiggled her butt in the air for a second, trying to get a footing on the floor, before realizing that her head was still on the ground. She pushed herself up on her forelegs.
For a second, her entire body weight rested on the mostly-air balloon that was her gut at the moment, and she could feel her plug shift for a second, her ponut tightening instinctually to hold it all in.
It did. The plug was well-designed and Tera strong from experience.
It didn’t feel that great, though. Tera winced anyway.
But once she was on her hooves and started awkwardly waddling toward her bathroom, she realized another problem she couldn’t get rid of until after this was over: the sloshing.
When she got into the bathroom, she grabbed onto the plug with her horn, ready to pull it out and vent everything, when she realized something.
The yeast, which was definitely what caused this, had two primary waste products: carbon dioxide and methane. All fine and dandy, to be expected, but for two problems.
One, carbon dioxide was toxic in high doses. She vented in here, especially given the lack of ventilation, she could easily knock herself out or worse.
Two was methane. Not that it stank—it didn’t; it was odorless, and the typical culprits in that respect were actually sulfur compounds—but that it was flammable.
So the only thing keeping her from unleashing a poisonous, flatulent firebomb on herself and her vicinity was a couple hands of plastic and a valve switch.
After some experimenting, she ended up back in the position where she was when she first noticed this whole mess, trying less to figure out how to solve the problem and more to work up the courage to up and do it. She was still growing, she kept reminding herself, and it while it would probably top off before she was in any danger, there was still the matter of “I am a poisonous firebomb” to take care of either way.
She decided that the best course of action would be to go up to the roof and hope for a breeze, which there typically was. To do that, though, she’d have to leave her apartment, take the elevator to the roof, and then vent there, all (hopefully) without being noticed.
Which, it didn’t help that she audibly sloshed with every step.
Slowly, veritably slowly, she crept her way out the apartment door, trying to keep her belly steady, making absolutely certain her tail covered her rear, hoping there wouldn’t be as much traffic as there usually was, which at the moment there thankfully wasn’t. She walked, step, by step, by step, to the elevator, feeling the fabric of the carpet brush against her all-too-sensitive skin, praying to no deity in particular: pleasepleasepleasepleasepleaseplease just let me take care of this, please? An Unknown God apparently answered her supplication, and she made it to the elevator without incident.
She pressed the button for “up” and waited a minute.
The elevator car whirred into place. The doors opened.
Tera had all sorts of wonderful cuss words in mind, but elected not to say them. (Not to mention that cussing in Ponish sounds really pathetic, especially when directly translated.)
She waddled into the elevator car, hoping the cat in the unusually formal attire wouldn’t notice. They made eye contact, as one does; his eyes shifted for a second. Well, there goes that idea.
“Uh… where you headed?”
He pressed the button (he was closer), adjusted his tie. He was obviously making an effort not to look.
They went up in silence for a second. The elevator was unusually slow for this kind of building, though it suited the purpose.
“…so, uh, how are things?” he said, apparently in an effort to break the tension.
The cat appeared to get the message, getting his phone out and idly tapping at the screen for a minute, humming to himself.
The elevator stopped, the doors opened, the cat got out. The doors closed again.
She had eight floors left to get to the roof.
She dropped onto her haunches, letting her belly bulge out in front of her. She didn’t really care anymore. If
anypony anyone else wanted to walk in on her, then they could be her guest.
She closed her eyes.
She opened them.
She was on roof level.
She got onto her hooves, winced at the pressure again, and waddled out toward the door.
The roof had a little building built on top of it with a couple restrooms and showers, and the elevator; out the door was a pool and some open space. There were a couple kids she didn’t know playing in the pool; their parents were conked out in some of the lawn chairs that were also up here, resting under parasols that at the moment blocked nothing, instead rippling uselessly in the soft breeze.
Which, there was a soft breeze. Good.
The kids seemed to be having fun with one another, so she crept out the door and crept around the building for a bit more privacy—
“Hey! Look at the big pony!”
“Cool! Hi, big pony! What’s your name?”
… Tera did not like children.
Panicked, she hobbled-bounced around the building, and when she was out of sight of the pool, looked and listened for the pitter-patter of little
hooves feet paws on the pavement.
She double-checked that she was downwind of the pool, raised her tail, put her weight on her gut one last time, braced, “grabbed” her butt plug, and yanked.
It was, thankfully, surprisingly silent; though she could feel the gases rushing through her rectum and out into the open air, the only wind she heard was already there before she started deflating, and the occasional grunts of pained pleasure she let slip from time to time. She lowered as she did so, all four hooves comfortably touching the ground now, the air starting to taper off and (unfortunately) make a more typical flatulent noise, which she could bear if it meant her gut felt better.
And then water started coming out her rear end, and she scrambled for the plug, but by the time she found it she had already drained completely.
And now her rump, and her haunches, and her rear legs in general were soaked with body-temperature water.
… well, at least she wasn’t cold.
She shoved it back up her rear. Wasn’t like there was anywhere else to keep it.
She walked, slowly, back into the building and downstairs, still more than a little pained from the whole experience.
Off in the distance, only half-registered:
“Hey, big pony—wait, you’re not big anymore!”
“Yeah, that’s weird, where’d it all—why’s her butt wet?”
A gasp. “You think—” A whisper.
“Yeah, let’s go look!”
Some splashing, the first few steps of little running paws on pavement, and then the door shut and she pressed the button for the elevator and lowered herself onto the ground, normally, as she could for the first time in hours.
Waiting for the elevator to come up to her, she realized something.
Her apartment had a window.
Going down, she almost felt stupider than she did going up.