Saturday afternoon came, and I was visiting Twilight. "So, what's the deal on the trip?" I asked her as we went downstairs in her castle, a book of some kind in her magic. "Why did you tell me to leave the Ember Celica behind?" Their absence felt odd, a testament to how often I wore them.

Twilight didn't answer until she led me through a doorway, leading to a round room, the only things of interest being a very large and very soft looking rug that took up most of the floor, and a mirror on the far side of the room. "The portal we will be using is stable, but, well, how do I put this?"

"Just spill it, Twilight."

She gave a sigh before answering. "When I go through it, I become a human, kind of like you. I made a friend on the other side, who used to be a unicorn before she started living there full time." She opened the book, wrote something short in it, and kept looking at it. After a few moments, she looked satisfied and set it in a cradle above the mirror, which started rippling like water in slow motion. "I know it's not the best answer, considering the implications, but I'm quite confident you'll be fine. Just follow my lead."

Twilight walked into the mirror, and then there was no trace of her. "So she becomes human on the other side. Transformation, then." I was suddenly having second thoughts about going through. Along with the second thoughts came memories of the pictures I'd seen Rarity use for inspiration, and curiosity was strong enough to push me into going through.

As soon as I stepped into the mirror, I started feeling weird. It wasn't like the times I'd been summoned, but more like being stretched and compressed at the same time. That was enough to make me black out for the rest of the portal.

Twilight landed gracefully once she was out of the mirror. "That's never pleasant," She said to herself before finding Sunset Shimmer standing nearby. "Hi, Sunset. How have things been over here?"

"Not bad at all," Sunset said. "I'm more interested in meeting Yang, though." Her tone became a bit more serious. "You have been careful to not bring. . . Certain types of pictures across, right? I don't want her freaking out about them."

"Don't worry. I've been very careful to keep it a secret from her. It's actually pretty easy, since she's at work most of the time." The conversation came to a stop when the mirror portal started glowing, drawing the two women's attention. A moment later, a tan pony with a long, blonde mane and matching tail was spat out, landing as gracefully as a brick. On her flanks were a golden burning heart emblem. "Uhh. . . Sunset?"

Sunset was already in motion, setting the pony's head on her lap and urgency in her voice. "Twilight, get ready to contain a possible freakout. Can you cast a silencing bubble around us?"

"Right." Twilight's hands lit up with a faint purple glow, and soon, there was an invisible bubble around them. Nobody would hear them.

The mare's lilac eyes began to open. . .

Everything felt. . . off, but at the same time, not quite wrong. Nothing was broken, I could still feel my aura, and someone was brushing my hair.

I slowly opened my eyes and saw a purple woman with Twilight's hairstyle in front of me. She was. . . Holding a yellow hoof? "Why am I feeling that?"

"Yang, I need you to stay calm, okay?" It was definitely Twilight.

"Bwah?" I would have actually said something, but my mouth felt longer than normal, which was very, very weird.

"The mirror turned you into an earth pony. I know it's weird, but please, don't freak out."

"Actually, you can freak out a little," another female voice said from above me, causing my ear to turn upwards, which caused me to start breathing a bit harder. "In fact, you probably should. Just, carefully. Don't hurt us, Yang."

"Bwah?" I repeated.

"Let's get her on her hooves." The brushing stopped, and two pairs of hands were soon moving me up. I blinked a few times as I got used to standing on four hooves. It was then that I started really noticing things, like the hooves, the shape of my everything, the mane, the tail, the fur, the way my tail wrapped around me when I realized I had no clothes on. The overload of information caused me to faint again.

The two former unicorns looked at the pony on the ground, not quite sure what to make of the situation.

Finally, Twilight spoke. "I'll take her back through the portal. It should turn her back to normal."

"I'll help." Sunset did as she said, and soon, Yang was in the portal back to Equestria. "Let me know whether she decides to come back or not."

"Of course." A moment later, Twilight went through the mirror again.

I came to again, feeling much more normal, much more clothed, and very confused about what I'd just experienced. Hooves, fur, the whole pony shape, the weird feeling of going through the portal, I remembered it all clearly. After pulling myself together a bit, I sat up against the wall, just breathing as I tried to work things out.

I hadn't been sitting against the wall for long when Twilight came through the mirror, an alicorn. "Yang?" She didn't look very long before she found and approached me. "Yang, I am so, so sorry about that. I. . . I knew the trip through the portal would be weird, but I wasn't expecting it to change you into a pony like that. I guess it's a good thing you didn't have your Ember Celica on, or we might have had a repeat of the trip to Seaquestria."

"Yeah, I guess," I managed to say.

Twilight started impersonating Fluttershy. "So, um, are you mad or upset at me for this? I'd totally understand, and if you want to punch me across the room-"

Her rambling snapped me out of my mood and put some wind in my sails. "Twilight, stop right there! I am not going to punch you just to feel better. It wouldn't work anyways. I. . . I just wish you'd mentioned the possibility of that in your letter."

"But I did tell you about my experiences before I went in, right?"

I had a finger raised and was about to tell her that she needed to be more explicit in the warnings before I realized that I had heard her explanation and should have been able to piece it together myself. After lowering my hand and sighing in defeat, I responded. "Just. . . Give me a few minutes and I'll go back through."

"You're sure? I mean, if you don't want to, that's-"

"Twilight, I really want to know where you're getting those pictures." I took a moment to adjust my position against the wall. "Is the transformation consistent?"

"Yes. Spike turns into a dog when he goes through, and no, I don't understand it either."

"Alright." Since I knew what to expect, that helped a lot. "Can you teach me how to walk on four hooves?"