The door opens and the others see a unicorn coming out of the door. Twilight instantly recognizes him.
"Starswirl the Bearded?" she says as he closes the door. The others look at Twilight with confused expressions.
"You know him?" asks Rainbow Dash.
"Well, not personally,” says Starswirl, “but she has read all about me in Equestrian history books from our world."
Rainbow Dash looks shocked. "Whoa! First a talking dog, now a talking pony?"
“It’s not just a pony, Rainbow Dash,” says Fluttershy, “but a unicorn! A real life, honest-to-goodness unicorn!” Fluttershy then squees in delight. “This is so awesome! It’s totally a dream come true to me!” Leaping high into the air, she adds “I feel like I could fly!”
Before Fluttershy lands with her butt on the ground, Starswirl catches her in his magical aura and gently brings her down. "Word of advice, my dear: don't try that unless you can get a pair of wings. At least, that's how pegasi do it in our world." Trotting over to Twilight, he speaks to her. "It’s an honor to finally make your acquaintance, Princess Twilight."
Twilight, at a loss for words, tries to speak up, but Starswirl raises a hoof.
"Permit me to explain. You see, my theories of parallel worlds and the Multiverse were all true. Over 1000 years ago, when I stepped through my Trans-Dimensional Gateway Mirror, I wound up in this world, where I encountered my human counterpart, the powerful, yet kind, sorcerer Starswirl the Wise.
“At first we were weirded out by each other, but we actually got along very well. We even began experimenting with spells that neither of us could accomplish separately, including one that had successfully unbound us to the time-space continuum. We no longer aged, nor did we need to eat or sleep, we simply exist. This allowed us to be able to travel to any period of time or any dimension throughout existence.
“Ever since then, we've been traveling around the Multiverse researching the pasts, presents and futures of one universe after another. We've seen many wondrous events and many incarnations of various beings from each world, and believe me, you're not the first Twilight Sparkle to ever experience this sort of conundrum, and odds are you won't be the last. It's just that the events of this timeline and the one we came from are turning out worse than most of the other ones, and believe me, things here are going to get much worse before they get any better.
“Now, because both of us Starswirls cast that spell together, we are unable to remain apart from each other for too long without having to return outside the time-space continuum, so we try not to meddle in the affairs of other worlds. But sometimes, it becomes necessary for us to intervene in order to prevent or to help resolve great catastrophes. Both of us Starswirls agreed that Princess Twilight here would feel more comfortable if she spoke with a fellow pony.”
“Now I don't have much time left, so pay close attention. What you have been experiencing this whole time is commonly known as a Full Cross-Temporal Consciousness Inversion. As we speak, your human counterpart is trapped in your body back in our world. Now my friend Starswirl the Wise had already paid her a visit, and rest assured, your pony friends are taking good care of her even as we speak.
“Now normally something like this would never happen. Unfortunately, this is the time when the Nibiru is coming."
"Ni-bi-ru… what's that?" asks Twilight.
Starswirl opens a flap on his saddlebag and levitates and old book out of it, handling it to Twilight. "Here. Everything you'll need to know about the Nibiru is in this book, starting at page 129.
“You see, the Nibiru was causing interference with my Gateway Mirror, and when your crown, the Element of Magic, was sent through it, it only caused additional interference. So when you and Spike stepped through the mirror, it caused you and your counterparts from this world to switch worlds as well as bodies. Then a failsafe in my mirror was activated, causing the mirror in the pony world to implode, thus sealing the portal from the other side to prevent any further abnormalities with the mirror portal."
"Wait, what?! The portal back to our world has been sealed?"
"Yes. Now the only way to resolve this matter is for you to use the power of your crown to reopen the portal from this end, then pass through the portal once more and all the problems of both you and your human self will be fixed. As to how you will get your crown back... well, I'm sure if these human girls are anything like your pony friends back home, then they will be more than happy to help you out."
Starswirl then starts to trot away from the girls, deep in thought. He gives a short giggle.
“You know... it's funny, really... back in Equestria, I've spent my entire life learning about every kind of magic I could possibly know, and yet... I always thought that friendship was just a waste of valuable time. Until the day I came here and met my human counterpart. We just shared such good chemistry that it was virtually impossible for us to not become the best of friends. It wasn't until that day that I had learned that there truly was magic in friendship. And yet... you, Twilight Sparkle, have learned that lesson far faster and better than I ever have. It's no wonder you were crowned a princess.”
“Yes, yes, that’s great and all, but--”
Before Twilight could finish, Starswirl raises a hoof. Twilight sees him glowing with static.
"I'd love to talk more, Princess Twilight, but I'm afraid my time in this world has come to an end. I must now leave this dimension.”
“No, wait! I still have so much to ask you!”
"Just have faith, Princess Twilight. In yourself, your other self and your new friends here.” Twilight gets up and runs towards Starswirl. “And don't forget…” Twilight tries to grab him. “That Friendship is Magic!" He suddenly disappears in Twilight’s hands. She puts up a disappointed expression.
For a while nobody said anything. Rainbow, in a state of shock, breaks the silence. "Wow... that was just... Wow." Pinkie opens her mouth to say something but Rainbow places a hand over her mouth to shut her up. "Seriously, though... WWOOWW!"
Applejack walks over to Twilight, who slowly starts to get up. "Hoo-da-lolly... I guess you weren't kiddin' 'bout that whole being a pony princess from another dimension thing, huh?"
"So anyways,” Spike speaks up, “what was all that stuff he said about this Nibiru thing?"
"Oh yeah, the book he gave me. I just gotta check it." Twilight then walks back to the desk and opens the book. "Page 129, right?" Everyone gathers around Twilight as she flips through the pages. "Nibiru, Nibiru... Here it is!" Twilight then starts reading. "A once in a life-time cosmic event that occurs once every 5000 years. During this time, the barriers that separate dimensions throughout the Multiverse begin to weaken, enabling forces from other worlds to leak into different worlds, often resulting in unpredictable conundrums and paradoxes. Many beings throughout cross-time have taken advantage of this event to use the power of the Nibiru to get what they desire." With a gasp, she realizes. "Of course, it all makes sense now! The Sunset Shimmer of my world must have sent my magic crown here to be claimed by the Sunset Shimmer of this world, so that they could both somehow take advantage of the Nibiru's power to get whatever it is they're after!"
"Oh great!” Rainbow Dash speaks up. “As if things weren't bad enough with just one Sunset Shimmer, now we've got two of her causing us trouble!"
"So, if this Nibiru thing is coming, when's it supposed to get here exactly?” asks Spike.
Twilight turns the page. "Well, according to this schedule, the Nibiru will be at its strongest point when this world experiences its next…” She gasps. “TOTAL LUNAR ECLIPSE!" Pause. "But the next lunar eclipse is on the night of the Fall Formal dance! So if Sunset is crowned Princess, then however the two of her were planning to use the Nibiru's power will succeed!” Twilight puts a determined look. “I can't let that happen. I must win my crown, no matter what!"
"But that only gives you until tomorrow night to win over every student in the school!” Fluttershy speaks up. “How will you pull that off now?"
“I have no idea.”
“Well, I’ll tell ya what,” Rainbow Dash speaks up. “We’ll be more than happy to help ya out. I was gonna help ya anyway when it was just for the dethroning of Sunset Shimmer. But now that this Nibiru is part of the picture, you need all the help you can get.” Pause. “So what’s the plan? How can I help you be princess instead of Sunset Shimmer?”
Applejack speaks up. “Folks right now only know Twilight from the video Sunset Shimmer posted online. We need to help them see her differently.”
The others put on thinking faces. After a while, Rarity speaks up. “I got it!” And by speak up, I mean yell loudly. “Now this might be a preposterous idea, but…” Rarity goes to her backpack and pulls out a set of ears and a tail. “What if we all wore these as a sign of unity?” As she puts them on, she continues. “In Freshman Year, they were very, very popular. Got everyone to show their school spirit. You know…” She then pulls out a cheerleader pose. “Go Canterlot Wondercolts!” As she pulls out more sets and distributes them to the other girls, she continues. “Sunset Shimmer was the one who divided us. Twilight Sparkle is the one who united us. And we’re gonna let everyone know it!” After Twilight has her ears, she speaks up. “What do you think?”
The others give thumbs up of approval.