Some time and several seasons of television later...
“I still can't believe I was encased in stone for all of this!” Discord complained, having stolen Fluttershy's seat in Twilight's castle. His snout was, as it had occasionally been since his reformation, buried in a copy of the Enkhiridion Caenite. “I would've loved to meet this 'Lord Carver' fellow, he must have been hilarious!”
“I never had the chance to meet him in person,” Twilight admitted, “and that book of his wasn't easy to find. Honestly though, I thought you'd be more interested in the Devourer Wurm.”
“Ugh, gag me with a spoon,” Discord said, rolling his eyes. “Ooh, look at me, I'm the Devourer Wurm! I'm going to break everything and eat all the souls! Boring! Predictable! No creativity at all!” Discord paused in his critique to turn a page. “Just as bad as this Everblight dullard. Who takes a nigh-unpredictable force that warps and twists the bodies and minds of all who encounter it and tries to organize it?!”
“I have to admit, it's eerie that I wasn't aware of any of this happening,” Starlight Glimmer said sheepishly. “I guess that just goes to show how remote my little village was. None of us had even seen a steamjack.”
“I do feel like that little incident might have been resolved more quickly if I'd brought a few along,” Twilight commented.
“The Great and Powerful TRIXIE had no idea what was going on while she was on that rock farm, either!” The obvious pony contributed.
“Celestia really should have asked Fluttershy to reform me sooner,” Discord complained. “I would have been very helpful, you know.”
“Helpful like when you saved us from Queen Chrysalis or helpful like when you betrayed us to Tirek?” Twilight shot back testily. Discord had been moaning all day.
“You're never going to let me live that down, are you?” Discord grumbled. He popped Twilight's horn off and made a show of inspecting its spiral.
“Give that back!” Twilight demanded, flying up to glower at Discord at eye level.
“Fine, fine.” Discord plugged the horn back into place. “Really, though. Nobody's perfect, Twilight.”
“No, they're not.” Twilight arced some magic through her horn to make sure it was still in working order. “But you seem to need reminding of that more than most.”
“I probably do,” Discord admitted without a hint of embarrassment.
“Something just occurred to me,” Twilight said rather abruptly. “Speaking of ponies who weren't around for this. I have to go write a letter, please excuse me.” The Princess of Friendship hurried out of the throne room, leaving her friends to make of her exit what they would.
Sunset Shimmer and her friends, having returned from Camp Everfree just days previous, had gathered at Sunset's summons around the statue in front of Canterlot High School. With the exception of Sunset herself, everyone seemed more than a little confused. Finally, Rainbow Dash asked the question they were all thinking.
“So, what are we doing at school?” Dash asked. “We still have like a month of summer vacation.”
“Closer to a week and a half,” Twilight corrected absentmindedly.
“If I keep saying it's a month, it'll be a month, right?”
“It'll feel like a month, anyway,” Applejack grumbled.
“I'm not really sure,” Sunset admitted. “Twilight's message just she had something important to tell us.”
Everyone looked expectantly at Twilight, who blushed deeply. “I -I didn't-”
“Oh! Not you, I meant pony princess Twilight,” Sunset hastily explained.
“Oh!” Everyone else said at once. Except Pinkie Pie, who said “Well duh! If it was her she would've told us already!”
Some days, it was hard to be friends with Pinkie Pie.
Suddenly, the portal opened and Princess Twilight emerged. In her arms was a large, thick book with a brown cover, so massive that it hid her entire torso with its bulk.
“Good, you're all here,” Princess Twilight said, smiling. “Lookin' good, other me!” She winked at her always-human counterpart, who blushed, flattered and fundamentally confused, at the compliment. She still hadn't quite come to grips with the existence of another world in which a talking, anatomically absurd pony version of herself was an honored member of the royal family. Much less one who thought she was pretty.
“So, what'd you want to talk to us about?” Rainbow asked.
“Well, mostly this concerns Sunset, because it's about Equestria, but the rest of you will probably want to know about it, too.” The Princess shifted the weighty tome in her arms, revealing its title: Enkhiridion Caenite.
“What do you mean?” Sunset asked. “You know what? Let's go to the library and find a place to put that book down. It looks really heavy.”
“Yeah,” Princess Twilight admitted. “I'm not used to lugging things around without my magic.”
“You mean like this?” Twilight asked, lifting the book with her new magical power.
“Whoa!” Princess Twilight was delighted. “Okay, you have got to tell me about this!”
“You first,” Sunset said, leading the way into the school. “What did you come to talk about?”
“Oh that. Well, it's a little embarrassing, but something really crazy happened in Equestria a while ago, and I only just recently realized that you probably never heard about it.”
“I have been out of the loop, but what about the magic books?”
“It, uh, was before we started using the books,” Princess Twilight said sheepishly. She didn't like to directly reference the time Sunset Shimmer had turned into a raging she-demon and mind-controlled the student body into a laughably under-powered invasion force in a doomed effort to conquer Equestria.
“I, uh, I see,” Sunset immediately recognized her meaning. Twilight lowered the tome onto a library table and Princess Twilight opened it.
“I'm going to leave this book with you as a reference,” Princess Twilight told Sunset. “For now, I'll try to keep this to a brief overview. Settle in, girls, I've got a story to tell!”
A week and a half later, the girls once again found themselves gathered at the statue, this time after the first day of class, and at Sunset Shimmer's summons. The orange ex-pony was clutching the Enkhiridion Caenite tightly in her arms and grinning somewhat maniacally. Her friends were more than a little concerned about the gleam in her eyes.
“So uh, what did you wanna-” Applejack began.
“We're going to build a steamjack!” Sunset interrupted with what sounded disconcertingly like a cackle.