From the source:
As the Dazzlings passed out, the Doctor and his company stepped out of the TARDIS, the Doctor changing before the mares' eyes as he slumped down onto four hooves. That, however, didn't surprise Twilight nearly as much as the figure standing before them. It was another pony with a soft lavender coat, and blue hair with streaks of pink and purple sliding back along her head.
"Princess." The Doctor and Sunset said in unison as they bowed toward the monarch.
"Doctor." the winged unicorn replied, bowing her head to the ancient legend. A sweet smile swept across her face as she reached to hug her friend.
"Sunset, it's been a while." She giggled.
Sunset giggled too. "Yeah, it has, Twilight. What's new?"
"A lot actuuu-" Princess Twilight droned on that syllable for quite sometime as she met eyes with her double from through the looking glass. "uuuHi." She followed up with a nervous smile.
Twilight did nothing but wave at her counterpart.
"Shy, huh?"
A nod.
"Not big on friends, huh?"
A shake of the head.
The princess sighed as she turned to her time traveling friend. "Help her, okay?"
The Doctor rolled his eyes as he nodded.
"Pleasantries aside, we're here for one thing, then we got to go." The Doctor said, getting impatient.
"And that is, sir?" Twilight asked.
The Doctor gave a nod to Sunset who used her magic to levitate two of the three amulets worn by the Dazzlings. The Doctor presented the third from his coat. The princess gasped.
"A-are those?" The princess asked.
"Yes, Twilight, the Dazzlings are in there," Sunset gestured her head toward the TARDIS. "And we really don't want them to come out here."
"So, please, princess," The Doctor interjected. "Take these two stones, and hide them across the land. That way, if they ever decide to come through the portal again they'll have a hard time finding them."
Princess Twilight nodded as she began to take the two gems from Sunset.
"But what about the third?" The alicorn asked the Time Lord.
"I'll keep it with me. They'll unstoppable united, so if they think their precious amulets are only in Equestira, they won't think to look in there." The Doctor nodded to his box.
While all this talking was going on, Twilight decided to leave this group, and back into the box. She had seen proof that magical ponies existed, and decided that that was enough for her.
"Hold on a second Twilight." The scientist felt shivers going down her spine as she heard her own voice call for her. She turned back to see that the princess was standing shoulder to shoulder with her friends.
"Take a picture for us." Sunset said, handing the girl her cell phone with her magic.
Twilight concentrated, and slowly but surely, she began to reach out with her mind, and took the phone.
"Now hurry up, and take the photo." The Doctor ordered, not bothering with the rest of a threat. Twilight did as she was told, and snapped the picture. Hugs were given, and reluctantly received as the Doctor and Twilight went back into the TARDIS. Sunset was set to join them when the princess asked her over for a moment.
"Yes?" Sunset asked.
"Do me a favor, Sunset."
"Sure, anything."
"Befriend Adagio."
"WHAT?!" Sunset asked in shock. "Are you crazy? I'm barely getting by making friends at school!"
Princess Twilight hushed her friend. "Shh, I know. Look, we forgave you when you destroyed the school, and stole my crown. Why not show her a little compassion too? If you be a friend, you'll have more friends. 'kay?"
Sunset pondered that for a moment, and nodded, making a mental note she'd write down later. "Okay, princess. Thank you. I hope to see you again." the yellow unicorn smiled as she went into the box.
"Me too. Bye." the princess waved.
Back inside the Doctor was busy calculating the jump back through the portal.
"Hold on tight." He said as he threw the switch to start the engines. A whirlwind of energy erupted causing the box to be thrown back across the void to the school.
The TARDIS wheezed as its engines shut off to cool.
"Where did Twilight go, Doc?" Sunset asked as she stood up looking over her human features.
A loud scream could be heard from somewhere in the ship.
The Doctor stifled a laugh. "Somewhere, and don't call me 'Doc'." He ordered.
"Sorry."
The Doctor nodded. "Now, let's wake them up." He bent down to where Adagio was, and saw that she was weeping. He thought little of it as he entered her mind to steady her for her awakening.
Sunset just yanked the patches right off the other two causing them to scream in terror as they awoke.
"What happened?" Sonata asked frantically.
"We lost, that's what." Aria said begrudgingly. "And do you know who's fault it is?"
Sonata looked confused, and shrugged. Aria groaned, and pointed at Adagio.
"Hers! Now, let's beat it. I can't stand her anymore."
"Bye, Daggie." Sonata waved as she followed Aria out of the TARDIS, and off towho knows where.
Sunset looked sad. Maybe if she helped Adagio they could all be better friends. She fumbled with the idea Twilight had, and decided to be the better person……