"When you had Fluttershy go over with me how animals walk on four legs, I thought you were just being weird," Wallflower noted as she wobbled across the marble floor.
Sunset laughed - and only slightly at the unsteady green earth pony. "Nope. The portal's actually pretty good at smoothing things out - we're pretty sure it uses your dimensional equivalent as a template to bridge the gap. It uses their form to figure out what and how you should be. But it's still a big change, and you'll need a minute or two." She paused, then leaned closer with a conspiratorial smirk. "You should have seen how badly Rainbow learning to fly went. It took her so long just to stop crashing into everything."
The two shared a laugh and a smile - then Wallflower leaned against Sunset. "Okay. I think I'm stable enough to not embarrass you in front of royalty."
Several hundred yards and three Royal Guard checkpoints later, Wallflower was having second thoughts. "I don't think I'm mentally stable enough to not embarrass myself in front of royalty."
Leaning in, Sunset put a leg around Wallflower's withers. "Relax. It's going to be fine. Think of it this way - you knew you'd have to meet my parents some time when we started dating. This is just a bit more... Intense."
"She's the immortal living avatar of the sun, ruling over an alien horse dimension."
"Pony dimension," Sunset corrected.
Wallflower just looked at Sunset. Who promptly kissed her and they both devolved into giggles.
The last line of Royal Guards nodded and the doors swung open to admit the pair.
Two alicorns awaited the pair in the Solarium - a grand space that was half greenhouse and half lounge, enclosed on nearly all sides by glass. It was bright, warm, welcoming and made Princess Luna look a bit uncomfortable. Still, it was just the right spot for this meeting and Sunset knew it. The look on Wallflower's face when she saw the meticulously preened garden confirmed it.
Sunset concentrated to keep her focus on Celestia and Luna, despite the urge to watch her girlfriend geek out silently over the Equestrian plant life. "Princesses," she began with a smiling bow of her head, "It's my pleasure to introduce you to my marefriend, W--"
"Sister!" Luna cut in abruptly, knocking Sunset's rehearsed introduction aside.
Not that it would have kept up much longer, because to Sunset's surprise? Luna wasn't addressing Celestia. No, that was clear when she teleported across the room to joyously embrace an incredibly confused Wallflower.
"Sister, it is so good to see you again! It has been far too long - I had thought that perhaps you had not forgiven me for the Nightmare and... had...." The Princess of the Night finally realized something was up by how the other three were staring at her. "....You're from Sunset's world. Oh dear."
Celestia coughed into her hoof. "Er, yes Luna. This is Wallflower Blush from Sunset's world, who we have never met before in any capacity and don't know." She smiled far too widely.
Which Sunset didn't buy at all. She had seen her former mentor wear that expression enough times. "Princess Celestia." Her scolding tone was cue enough for the alabaster alicorn to shamefully look elsewhere.
Fortunately, Luna was less evasive. "Well, I suppose a sister from another dimension is still a sister." She de-hugged Wallflower and took a step back. "It is a great pleasure to meet you, Wallflower. I apologize for mistaking you for your counterpart."
"She's not your sister," Sunset pointed out with mild disbelief that this was happening.
"She's an alternate version of my sister," Luna insisted.
Sunset ground her teeth in frustration. "Wallflower isn't related to you. She's not even an alicorn."
"Yes she is," Luna again insisted, before casting a quick dispelling charm.
In a flash of light, Wallflower's earth pony body vanished. In place of it was a tall alicorn - regal, composed and practically vibrating with energy. It still was definitively Wallflower, though her forest-green mane was even more wild now and dotted with living flowers. Her eyes, however, had shrunk to pinpricks. "what."
And then Sunset started screaming.
Celestia was otherwise occupied for the moment, her wings and hooves wrapped around Sunset. The amber unicorn was rocking back and forth in a ball, mumbling over and over about mirrors and curses and how fate was conspiring against her.
Wallflower was taking it better, but she had the advantage of not fully grasping what was going on around her. Still, Luna was trying her best to help her through it.
Luna and a large glass of wine.
"So." Wallflower took a deep breath to try and stabilize herself again. "I'm your sister?"
"Essentially," Luna clarified. "The relations of alicorns are complicated before accounting for alternate dimensions, but sister is as close a word as exists for us."
"And I'm an immortal super-being who controls..." Wallflower squinted. Celestia was the sun, Luna was the moon and that left... "The stars?"
An amused smile played over Luna's face. "The stars are mine, but 'tis an excellent guess." She turned to look up at the sky and the afternoon sun. "Our sister is the light, I am the dark and you..." She extended her forehoof out into the sun's rays - and looked below it. "You are the shadow that is neither light nor dark. Something between. Three tribes, three princesses."
Wallflower frowned. She didn't particularly like that, but it wasn't her life to argue over. "So where am I? I mean, where is she.. I mean..." She felt a headache coming on already.
"I do not know." Luna turned as Celestia pulled a still rattled Sunset over to them. The poor unicorn was still unsteady in more ways than one, but she had stopped howling for Harmony to strike her down where she stood. "In truth, we have not seen our Wallflower since I returned from the moon. I have been quite concerned she still holds a grudge."
Sunset hesitated for a moment before hugging Wallflower - or at least what of her she could reach. The two clung to one another in a sea of madness.
Celestia stepped into the conversation next. "Our Wallflower always preferred to live a quieter life than either of us. She was ill suited to the roles we took, enjoyed embracing her earth pony roots, and often travelled Equestria in disguise as one. One day, she simply... didn't return." The Princess of the Sun let out a deeply-held sigh. "I know she's alright, but that only does so much." She reached out and set a hoof on Wallflower's shoulder. "Please forgive Luna's mistake. We simply miss our Wallflower dearly."
Gently - hesitantly - Wallflower let out a deep sigh. "I know. I understand. And I'm not offended! It's just a lot to take in. I thought being a horse was weird enough."
"Pony," all three Equestrian natives corrected at once.
Wallflower blushed again. "W-well anyway. I guess it's good to know that at least one version of me is good at being in public and talking to um.. ponies." She puffed her chest out proudly. "It means that there's hope for me, too!"
Luna and Celestia shared a brief look. "Actually," Celestia hesitantly corrected, "Our Wallflower is terrible at those. Even before her disappearance, she was the worst people-pony of us."
The darker sister nodded in agreement. "Brilliant with plants, intelligent as any scholar, holding a heart more caring than a mother for her newborn foal - and completely incapable in any sort of social situation."
"We love her, but she was never able to break out of her shell. And on the rare occasions she tried..." Celestia let out a deep sigh. "When we lost Luna, Wallflower attempted to take up her mantle and rule. It was perhaps the worst possible thing she could have done. Not only did she have the same pressures that Luna did, but she as well had to operate under our fallen sister's legacy as well." A sad smile crossed her lips. "At one point just prior to her self-exile, she dubbed herself the Princess of Being Overshadowed."
Wallflower winced. This was sounding more and more familiar.
Then Sunset cut in with an uneasy laugh. "Wow. That's pretty amazing." She hip-bumped Wallflower. "She's a Princess and you're the well-adjusted one."
Wallflower stopped. She blinked. "...Huh." Sunset's statement was turned over in her head, examined from different angles. "You know, you're right. I think you're actually right!" She broke out laughing. "I was my own worst enemy until you broke me out of it. Now I'm hearing about the alternate me and feeling kind of... sad?" Wallflower turned to Celestia and Luna. "She's so powerful and strong, but she can't beat herself. I know what that's like. ...Without the power."
"You did have the Memory Stone," Sunset added with a soft smirk.
Luna smacked Sunset in the back of the head with a wing. "Marefriend or not, that was most unkind Sunset." She turned from the grimacing unicorn to her green sister. "But you are correct. We love our Wallflower and miss her, but you are far more comfortable in her skin than she was. For this, I credit something you have which she was never able to adopt."
"Friends?," Wallflower half-questioned.
"Friends," Luna confirmed with a knowing smile.
Sunset bumped a hip against Wallflower playfully. "To think. All of those differences between you two, and what really makes the difference is something so seemingly small. For want of a horseshoe, right?" She winked slyly.
Instantly, Wallflower perked up and eagerly corrected Sunset. "Ponyshoe!"
All three Equestrian natives sighed heavily and shook their heads.
Hours later, Sunset and Wallflower bid the Princesses farewell and left to retire to their room. The marble halls of Canterlot seemed far more welcoming this time, even with the same echo. Though Luna had taught Wallflower how to re-assume her less striking earth pony form, Sunset kept looking at her marefriend with a mixture of fascination and jealousy.
The sound of their hooves echoed through the halls as they moved towards the guest rooms in the east wing, their conversation for the moment kept low.
"I guess I should be thankful," Sunset concluded. "I didn't think that would be how you'd hit it off with the Princesses, but I'm still glad you did."
Wallflower laughed again. "The look on your face was pretty funny. Maybe not the screaming, though."
Sunset sighed with the drama of Rarity. "I have issues, okay? I never said I was an angel."
One of the maids - a nondescript earth pony - stepped aside as they passed her. "Miss Sunset. Miss Wallflower." She bowed her head and was just as quickly gone into the maze of halls and rooms.
Perhaps a minute passed, and Wallflower tilted her head to the side in thought. "Sunset? The Princesses were pretty surprised to see me. I guess you didn't tell anypony who you were bringing?"
"Nope!" Sunset shook her head, looking pleased with the deception. "I just told everypony that I was bringing my marefriend and that I wanted it to be a surprise. None of them knew before we got here."
A smile came to Wallflower's lips - one more often on Celestia's. One that said she knew the answer to a question that Sunset hadn't thought of yet. "If nopony knew who I am, how did that maid we just passed know my name?"
