The Princess awaited his arrival. She knew he was going to be late, probably from preparing a truly royal entrance, complete with over-the-top music. She didn't blame him, of course. After all, he was her, just in another body.
After a while, her prediction came true, and a squad of trumpeter ponies and excessive confetti announced the arrival of their beloved, Prince Solaris.
“It's good to see you again, Princess.”
“As it is to see you, dear Prince.”
She offered him a throne next to the one she was seated in. Once he was properly seated their discussion began.
“So...” the Prince began “...I had a wondrous idea recently, so I assume you had the same.”
“Indeed I did, but now is neither the time nor the place for that.”
The firey-maned alicorn chuckled a bit. “No, not that idea...We'll have time for that later.” He gave her a quick wink, causing her to giggle. “I mean the other idea.”
The Princess smiled, intently. “Of course! It really is a marvelous idea, and could wield fascinating results.”
“Oh, absolutely. I just know they'll go for it, too. There's no way either of them would pass up such an opportunity.”
“Agreed. Should we call for them?”
“Absolutely.”
On that note, both alicorns began writing a summons.
Dusk and his friends were in the middle of another one of Berry's special Berry Bubble Bashes. Dancing, games, and plenty of chips and dip. Everything was in order. Everything except the sudden outburst from the purple dragoness.
“Dusk!”
The unicorn in question stopped and turned to his assistant.
“Huh? What is it, Spines?”
“You just got a letter from the Prince!” She holds it out to show it to him. “He says he wants to see you right away!”
A certain pink earth pony dropped their head.
“Aww, darn...just when things were getting good.”
“I know” the rainbow-maned pegasus replied “What's the Prince doing sending you a letter at a time like this? This had better be important. What, did Strife escape again?”
“Puh-lease...” the white unicorn interjected “Don't go jumping to conclusions. We probably would've noticed by now if she'd escaped, because there'd be cotton candy clouds and whatnot. I'm sure the Prince has his reasons.”
“Aww, wassamatter?" the orange earth pony interjected, "Don't wanna see yer boyfriend, again?”
“I thought we agreed never to speak of that again.”
“GIRLS!” Twilight finally interrupted “It says here that the Princess wants me to come to Canterlot as soon as possible...”
“Well, that's good” Pinkie Pie burst out “because you can't possibly miss out on this party!”
This elicited a glare from the unicorn, who kept going as if nothing happened.
“...and that I am to come alone, not even with Spike.”
Twilight finally arrived in the castle city. Walking through town brought back many memories, mostly of places she'd go to study. However, the anxiety of the summons gave her no time to enjoy these memories.
She arrived at the palace and was escorted to the door to a room she had never been in before.
“That's odd. I don't remember this being here.”
Knocking on the door, she heard the Princess' voice granting her access, but her's wasn't the only voice heard. Another voice spoke in unison, and was much deeper in pitch.
Curious, she opened the door with much anticipation. In the middle of the room in front of her was her royal highness, Princess Celestia, perched atop her throne.
“Ah, Twilight Sparkle. Perfect timing.”
The deep voice was still audible whenever Celestia spoke, but Twilight couldn't see where it was coming from.
“Princess Celestia!” A deep voice was heard when she spoke, as well. However, something was different. Could this room be enchanted to alter the echo of anyone who speaks within the confines of its walls? What would be the point of that?
Twilight suddenly realized that she had stopped in mid-sentence to ponder this, and continued.
“Why'd you call me here? Is something wrong?” She tried to ignore the echo.
“Oh, don't worry. Nothing is going wrong. On the contrary, I have brought you here for an important scientific study.”
Letting out a sigh of relief, the young student smiled to herself at the thought of doing something scientific.
“Of course, Princess! What will I be studying? A new species of bird? Some strange plant? An experimental spell?”
Celestia smiled, but said nothing. Instead, she stood and motioned for Twilight to follow her. She led her student to the far wall of the room, where a mirror was located, with a frame that the young unicorn decided was a bit too fancy. However, something about this particular mirror didn't seem right. Twilight wanted to get a better look at it, but couldn't from the angle she was standing in.
Finally, Celestia stepped aside and motioned towards the mirror.
“Take a look. This will be the focus of our study.” The deep echo was louder than before. Could it have been coming from the mirror? Was it magical? Perhaps that's why it looked so fancy, and why it was the only object in the room.
Even more confused than before, Twilight slowly and cautiously approached the mirror from the side, unsure of what to expect when she gazed into the magical reflective surface.
Walking along the wall, she ended up closing her eyes in anticipation, holding her breath. When she knew she was standing in front of it, she turned towards it and hesitantly opened her eyes, slowly at first. There, in the mirror in front of her, was nothing more than her own reflection.
“Huh? I don't get it.” At least now she could determine that the deep echo was definitely coming from this mirror. “You want me to study...myself?”
The Princess chuckled a bit.
“I never said you would be studying. Instead, we will be studying you.”
“What? I don't understand. What do you mean? Why are you studying me? Wait a second...who's 'we'?”
Celestia's horn glowed a bright green as the leaned forward and tapped the mirror. Almost immediately, a loud rumble was heard as the wall began to shake. After a few seconds, several bricks began to disappear in bright flashes of light, seemingly at random. One by one, the bricks of the wall vanished until none were left, and the mirror floated in mid-air where the wall used to be. This made Twilight even more intrigued in the mysterious object.
She stared deeply into it, focused and intent. She stared into her deep purple eyes, which began to burn from staring. She blinked, but in that split second, she could see a flash of light.
When she opened her eyes again, what she saw in front of her was the same as when they closed. In front of her stood the familiar form of a purple unicorn, with purple eyes and purple hair with pink highlights.
The only difference was the mirror, which had vanished with the wall. It was only when she realized this that she began to notice several other differences. The unicorn in front of her was slightly taller, less curvy, and had a mane with a slight curl to it.
The “reflection” was the first to speak.
“T-...Twilight Sparkle?”
There was no echo when he spoke, and this seemed to confuse him just as much as it did her.
“Dusk Shine!”
The echo from her voice was gone, as well. That's when she realized that he was the echo, and he seemed to come to the same conclusion.
“How did you you get here?” they both asked in unison.
“Huh? But...”
The Princess interjected, "We are in no ordinary room, my dears."
"The mirror that used to be here was actually a portal between our two worlds," the Prince added.
"If you look behind yourselves, you'll see that, along with the wall between us, the doors you entered have also vanished. That is because we're not quite in the same room we just were."
"When we activated the portal, the wall didn't disappear...we did. This room is sort of a halfway point between our worlds."
The two purple unicorns stood silently for a while, until Dusk broke the silence.
"But when you activated the spell, each brick disappeared one at a time. If we went from a room with a wall to a room without a wall, why didn't it all just go away at once"
Twilight nodded her head, she was about to ask the same thing.
Prince Solaris remained silent for a second and then laughed. "Oh, my dear pupil. You know how much I like theatrics."
Celestia then responds with a smile. "In all honesty, there was a wall here, but simply saying that we moved to another dimension and then removed a wall took away from some of the mystery."
Twilight rolls her eyes. Yes, that definitely seemed like something her teacher would do.
"Ok, so are you going to explain what this 'study' is?"
The Princess simply smiled and replied "It's like I said. We are going to study you two."
"Dusk Shine and Twilight Sparkle, you two will switch places for an entire week. Twilight, you will be coming with me, and Dusk, you will be going with Celestia"
"We will study your behaviors to see if there's any significant difference in your daily routine when everypony around you is the opposite gender."
Although she was very excited to participate, this idea worried Twilight. She had complete faith and trust in Dusk, but she knew that, being a guy, it would only be a matter of time before he started having "thoughts" about her friends. She couldn't see it, but Dusk was having his own concerns about the experiment, and he was the first to state his opinion.
"Are you sure this is a good idea? What if Twi-"
He was interrupted by Solaris holding up his hoof to silence him.
"We said we want to study what happens. If something is concerning you, do not let it, for that is what we wish to discover"
Twilight occasionally glanced at her male counterpart. What was he going to ask? Did he not trust her for some reason? This constant worry ate away at Twilight, but she remained silent.
Celestia then lightly stamped her hoof on the floor. "The experiment shall now commence. Dusk Shine, come stand next to me. Twilight Sparkle, by the Prince."
The purple unicorns did as they were told, but glared at each other in distrust as they passed by each other.
When they were in their proper positions, Solaris loudly announced “Let the experiment begin!”
The wall began to form again as Twilight and Dusk continued to glare at each other until they couldn't see each other anymore.
