Taken, 5

You remember the feeling of anxiety lingering even as you let Zephyr's words work on you, taking another few careful steps until you were standing trembling slightly in front of the pair of humans smiling down at you.
"Miss Braeden," the woman who was going to be your Master had said, leaning down to.. wait, no.
"Miss Braeden," Zephyr's Master said? No.. Also not right. Something was terribly wrong with this picture!
Not the least of which was that it was all starting to fall apart! The memories fading quickly as you were pulled out of your dream! That voice wasn't your Master's! It wasn't Zephyr's Master's voice either! It was the voice of that bad doctor!
"Miss Braeden!", the doctor chides, reaching out to poke your side. "Will you join the rest of the class or am I going to have to write up another fail on your report?"
You groggily blink your eyes open to stare in the angry face of the doctor who'd visited you back in the other room, Orchid sitting on her rump in front of one of the low tables behind him. When did she get up?
"If you would please?", the doctor grumbles, waving his hand towards the unoccupied table. "I do believe we've waited long enough."

With your mind still feeling a bit foggy, you reluctantly push yourself up from the bed and walk over to the unoccupied table, sitting yourself down on the padded floor as a soft yawn escapes you. You can't help but giggle as you hear the yawn repeated by Orchid, but your ears flatten against your head as you hear the doctor scraping his throat and you quickly fall quiet again.
"Since you both refused to partake in the previous test," the doctor starts in a surprisingly optimistic tone of voice, and you glance up at him in confusion. He, on his part, is doing his best to ignore you while he pulls a pair of pages from a folder he held under his left armpit, "we have to do a similar, but considerably simpler, test today."
You find yourself blinking at that. Simpler? How much more simple can a test get than putting four differently shaped blocks in four equally-shaped holes?
The doctor wastes no time in showing you what he meant, as he leans over you and places down one of the pages on the table. A page holding nothing but two symbols on it; a square and a circle.
As the doctor moves on to put a similar page in front of Orchid, you find yourself squinting at the circle. Something seems off about it, but you can't put your hoof on it until you lean a bit closer. What looked to be a perfect circle from a distance, starts to look less and less like one as you draw nearer.
Corners start to break out from the circular shape, and you notice the circle is made up out of a great many straight lines. It's not a circle at all, but a multi-sided polygon instead! Thirty or more sides at the very least, if you had to estimate, the illusion of it being a circle almost perfect when seen from a distance. With your nose almost on the paper however, much of the illusion is lost.

You are about to ask what the deal is with the symbols, when the doctor nods towards the windows behind you and orders; "Please point out the symbol with the least amount of sides."
You blink up at him, while Orchid quickly stomps her hoof right in the center of the "circle". You sigh out at her, then point your left forehoof up at the square on the picture.
"Obviously the polygon has way more sides than the square," you mutter, but then have to quickly duck away as the doctor moves in to practically tear the paper out from under your hoof!
His demeanor went from just being condescending to actually looking at you as if you did the worst thing imaginable and you feel your tail and ears sink low as he moves over to Orchid's table.
"Thank you, miss Orchid," he tells her, taking the paper from her in a far less agitated manner and putting both back in his folder. Without another word he turns for the door and you watch, in mild amusement, as he leaves the room as fast as he can while still retaining some manner of dignity.
"Well, that was interesting," you chuckle to yourself, giving a soft nuzzle at your sister's neck as she joins you.
"I liked that test," she offers, her innocent face all smiles to you. "It was easy!"
You look at her a moment, then shake your head slowly. "Yes, little sis, it was. A bit too easy, don't you think?"
"Yeah!", the muscular pink pony quips with a slight frown. "Everypony knows it was the circle."
You decide to just nod at that. She wouldn't understand. It's not her fault, really. She's a lot older than you, in terms of how much time she's spent as a pony, and you're sure the process Zephyr's master used has become a lot more refined since then.

Your own body is much less muscular than Orchid's, even if you're both earthponies. Her head is bigger, her features more masculine if simply by how much thicker everything is. Her eyebrows are about twice the size of yours, but no less functional.
Your form is slimmer, leaner, more compact in ways. Your hooves are smaller but provide just as much stability as you would expect Orchid's to. The only thing Orchid got on you in that area is her extra weight.
Between Autumn and Orchid on the one hoof, and Zephyr and yourself on the other, there is a clear progression of how well the transformation panned out. You always felt quite at home in your pony body, perhaps helped by the initial thought it was all just a dream? By the time you realized it wasn't, you had already grown so accustomed to being a pony, that the thought of having to deal with a human's body seemed as alien to you as having a pony body had been before.
Walking around on four hooves, playing with the other ponies, eating hay, oats, and everything vegetable - but no meat, everything felt so normal. After a lifetime of having had nowhere to belong, you finally found your place as a pony.
You found a Master, a sister, a life. And then these idiots decided to steal you away from that.
"Big sis?", you hear Orchid's voice break through your rambling thoughts, and you suddenly realize you're crying.
"Are you ok, big sis?", she wonders, and you cling your forehooves around her neck, burying your face against her fur while the tears flow freely. You're honestly glad you don't have to go through this shit alone.

You both sit like that for several minutes, with Orchid carefully patting your back trying to calm you down, but the sound of the panels in the wall opening helps more to distract you than your little sister could.
Apparently it's lunchtime, and you're happy to find a strawberry among the other assorted fruits in your bowl. Such a sweet and succulent treat helps your mind calm down and you crawl back on one of the beds after you had your fill.
Orchid bounces around the room a little, trying to burn off excess energy, but then starts to yawn and wanders over to the other bed. You're a little surprised as to why she doesn't join you, but then find her taking a corner of the bed sheet in her mouth before dragging it over to the bed you're on.
"I was just going to ask," you chuckle at her as she lays down and pulls the sheet over her, and she sticks her tongue out at you.
"It was a little cold last night, so I walked around in circles for a while to warm up again," Orchid explains, "and then the doctor came to visit us again."
You frown a little at that. "Wait, so you didn't have breakfast?"
Orchid nods at your question. "Of course I did! Just now," she mutters, curling up a bit under the bed sheet and closing her eyes. "And now I just need a little nap," she half-yawns, and soon is fast asleep beside you.

You look her over a bit while your thoughts skip from one random tangent into the next, until a bump from the other side of the mirrored glass makes you perk up. The glass wall on the right side of the door is still shuddering from the impact of something hitting it from the other side. You clamber down from the bed and walk up to it, watching the glass settle again as you approach.
What was that?
You put your face close to the window again and try to look into the room beyond, but just as before it is nigh impossible to make out anything on the other end.
You sigh at the uselessness of your actions and walk over to the door instead, putting your ear to the crack between it and the frame in the hopes of catching some sound.
It is barely audible, but you do hear something that can be best described as agitated voices. One male, one female, then another male speaks up. It's impossible to tell what they're talking about exactly, but one of the voices is all-but screaming, while the others only speak as loud as they need to to provide some counterbalance to the shouting male.
The sound of a door slamming shut makes you jump and you see both windows tremble in their frames as you back away from the door.
Whatever's going on outside is something you can only guess at, but you're slightly amused at it. Dissent in the ranks of your captors?

What follows is mostly silence, and the sound of Orchid's soft snoring. You pace around the room for a while, trying to decipher what the shouting and door-slamming might have been, but there's just not enough information for you to string things together.
Any situation could have ended in humans shouting at each other. You know it happens a lot, regardless of the cause.
Want a sandwich in a restaurant? Shout at the waiting staff.
Want to cross the street but the light isn't green yet? Shout at the cars going by because they're obviously slowing you down.
Want to go outside but it's raining? Throw a few obscene remarks towards the gods and then spend the rest of the day shouting at everyone who even remotely enters your field of vision.
Humans REALLY liked to shout.
With the increased sensitivity of your pony ears, you yourself barely shouted, except for when your emotions got the better of you. The large shells on your head were capable of turning in almost every direction you needed them to turn to, catching sounds your human ears would have never been able to hear. Shouting hurt your ears, so you rarely did it.
Orchid rarely shouted either. And you think Autumn's excited shouting was just that; excitement. Nothing bad, surely.
You find yourself having a new appreciation for ponykind and merrily pad over to the bed your little sister is resting on, giving her a soft kiss on her forehead when you draw near enough.
It doesn't matter that you're stuck in some humans' institution. In this doctor's practice from hell. You're together with your little sister, you're a pony, and your Master is most assuredly looking for you. Even if you don't believe she'll be able to get you two out of there on her own, you must hold up the idea for Orchid's sake.