Rainbow zoomed between the rows upon rows of bookshelves, carrying a bundle of books in her hooves. She took a sudden turn to the right, and shortly after screeched to a halt in mid-air, then gently floated down to deposit the books on the table at which Luna, Twilight and Rarity were sitting.
"Thanks, Rainbow," the second said without looking up from the tome she was reading.
"Is that all of the books Celestia listed?" Rarity asked, flipping several pages on a book while glancing at another opened one lying on the table.
"I believe so, yes," Luna replied, her face half-hidden behind several opened volumes floating in front of her.
Rainbow perched atop a precariously constructed and barely stable tower of books, built too close to the edge of the table, and lazily studied the accidental architecture of the piles of old large tomes the three magic users had placed to the side as they focused on other volumes they considered more likely to hold the answers they were looking for. "Anything else I can do?" she asked as she rolled to the side with cat-like motions.
Twilight, still without looking up from the page, levitated a blank piece of parchment and a quill and wrote down a long list of titles. "This are all the books I know of that might be useful and Celestia didn't mention. It's unlikely we'll find anything in them, but I still suggest we gather them in case we can't find something useful in the ones we already have," she said while passing the list to the pegasus.
"Yes ma'am!" Rainbow replied as grabbed the list, then lifted herself up and prepared to dash off.
"Rainbow, could you please fetch me this as well?" Luna asked, momentarily stopping the pegasus as she lifted a single piece of paper with a lone title elegantly written on it towards her with her magic.
The pegasus stopped for a moment, grabbed the paper and then flew away, starting to gather the books the others had listed.
"What was that, Princess?" Twilight asked, closing the book and switching it out for another.
"Nothing important, but as you said it's better to cover all possibilities," the alicorn replied behind her curtain of books, swapping several of them out for new ones.
Silence reigned for a while, the only sounds those of pages turning and the occasional thud from Rainbow dropping some of the books she'd recovered from the depths of the library on the table.
"Still nothing here," Rarity sighed, opening up another book in front of her, "what about you."
"Nothing," the alicorns replied in unison.
Rainbow left some books, then flew away again.
"Twilight," Luna suddenly asked, "do you know what a headstall is?"
Twilight was taken aback by the suddenness of the question, and stopped reading for a moment, almost looking up. "I... Yes. Why do you ask?"
"I assume you're only familiar with the traditional use, right?" Luna turned a few pages on different books.
"I... There's another use for them?" Twilight asked, confused.
"Yes. It's not important now though, go back to your research." Luna picked up a few new books.
Rarity looked between the two, and chuckled inwardly.
Rainbow came back in that moment, carrying yet more books. "Did something funny happen?" she asked.
"It's nothing, darling," Rarity dismissively replied, waving a hoof, her eyes still focused on the books.
The pegasus shrugged, and flew away once more.
Twilight's book closed with a thud, as another took its place. The alicorn sighed. "This really feels like it's going nowhere. Princess Luna, are you sure you don't remember anything else about how you created Apple Bloom? Anything at all?"
Luna grimly shook her head. "I am afraid not, Twilight. My memory of my time as Nightmare Moon is rather foggy, I must admit. It is not a part of my life I ever particularly wished to remember since I came back, so I believe I might have let myself forget portions of it. I see now how that was a mistake."
"Don't say something like that," Twilight replied in a gentle tone, "nopony can blame you for this."
More books landed on the books. "Actually, Twilight, I'm pretty sure we can blame her for this." Rainbow left again.
"I meant... Oh, never mind," Twilight huffed, deciding it was pointless to discuss with someone when they only heard a third of what you said at best.
Rarity clicked her tongue. "Actually, Your Majesty, there could be a way for you to recover some of your memories about this."
Luna set some volumes aside, shifting her glance towards the unicorn. "Such as?" she asked.
"Well..." Rarity closed her book for a moment, leaning towards Luna to whisper in her ear. "It would be about-"
"Princess?"
Luna looked up. "Yes, Rainbow Dash?"
"I, huh, found the book you asked for." The pegasus flew down to land in front of the alicorn, holding the large dark blue tome in her hooves. "Are you sure you gave me the correct title?"
Luna took the book in her magic, studying the cover. "Yes, this is exactly the book I was thinking about. Thank you, Rainbow."
"Oh." The pegasus pulled back slightly, rubbing the back of her head with a hoof.
Luna glanced at her. "Are you familiar with it, by chance?"
"I'm-" Rainbow Dash looked to the side "-familiar with the author. Does this happen to be, well, in line with their other works?"
Luna looked back at the book. "I believe so. I remember this being one of my favourites before I was banished, I believe there might be something here that might make it clearer to me what exactly my thoughts were like during my time on the Moon. It does approach a similar subject to what we are dealing with, after all."
"Understood." Rainbow sat back on a particularly large encyclopedia, staring at the ceiling.
Luna looked back at her with a smile. "I'd recommend it to you, when this is over of course. I'm sure you'll find it enjoyable."
Rainbow stared back for a moment. "Thank you. I'll consider it." She pulled out her list once more, making sure she hadn't missed any book on it. "Is there anything else I can help with?" she asked.
"Actually..." Rarity grabbed a quill for herself and began to scribble something on a piece of parchment.
Luna looked at the list over her shoulder. "Oh! Of course, I should have thought of this myself, it does seem like a way worth trying." As Rarity finished the list, she grabbed it for herself and added a couple of titles. "Good idea, Rarity. Were you thinking of doing this yourself or-"
The unicorn shook her head. "I am usually on the receiving end of such things. Part of my spa treatments, Aloe and Lotus introduced it to me on a particularly stressful day. I was thinking Twilight could do it."
Luna nodded, passing the paper to Rainbow, who took off immediately, somewhat puzzled by the titles she was reading on it. "That would certainly work. Even if I must admit I would have thought the roles to be inverted if me and her ever were to do something like that."
Twilight looked up from her book, as if startled. "I'm sorry, what were you two saying?"
"Rarity was suggesting an alternative method with which to attempt a recovery of my memories, and we were thinking you'd be the perfect candidate for it," Luna explained.
"Oh." Twilight turned a new page, looking back to the book. "What does it consist of?"
"You'll see once Rainbow has found the books we requested."
"About that," Rainbow cut in, depositing a new batch of books over the towers of literature. "I couldn't find this one," she said, passing down the list she'd received, folded as to only show one specific title.
Luna put a hoof to her chin. "Curious."
Twilight grabbed the list in her magic. "Oh, this is- Oh, well, yes, that is a good idea- Anyway, this book is in the restricted section, I believe it was moved there a little over two hundred years ago, after a small rebellion broke outnear the northern border."
"Whyever would Celestia think about putting a book like that in the restricted section?" Luna pondered.
Twilight stared at her.
Luna stared back. "Well, yes, I do suppose there might be a valid reason for that. Anyway, Rainbow, don't worry about it, I'll fetch it myself later. For now we should focus on the present task."
"Exactly," Twilight echoed her. "Even if that will likely help, we're still looking for something else here. Knowing what Nightmare Moon was thinking could certainly restrict our field of research, but we still need to find a way to purge Apple Bloom, and that probably means finding something she didn't know about in the first place."
Rainbow shrugged, then had to stop a pile of books she'd accidentally touched with her wings. "So do I just stay here doing nothing or what?"
"Well you could start doing some research yourself, we could certainly use a helping hoof," Rarity replied from behind a stack of volumes.
Rainbow Dash huffed. "I can't understand anything about this magic stuff, I probably wouldn't be of any help." She sat on top of books, pretty much the only thing she could possibly sit on given how they covered everything on the table and around it. After a few moments of waiting, the only sound that of pages turning, she perked up. "Hey, what if I went to Ponyville to check on the situation there? I can go there and back pretty fast."
"Oh, please, darling," Rarity chided her. "There's no need for something like that. I'm sure Applejack and the others are doing a fantastic job at taking care of Apple Bloom, there's nothing to worry about."
"If you say so." Rainbow sat back down.
Suddenly, after minutes of boring silence, a flash of light lit the room, followed by a small boom.
"I am terribly sorry I couldn't get here sooner," Celestia said, stepping forward. "State matters are such a taxing part of my schedule, and some nobles are just too stubborn. But I should be free for a while now, here to lend a hoof. This seems to be a most serious matter indeed." She looked over the four ponies, their gazes wide and pointed at something behind her. "Is everything alright?" She turned back, just in time to see the towers of books her teleportation had disturbed collapsing towards her in a tsunami of knowledge, inked paper and bindings.
At the thought of being buried under a mountain of books, Twilight found it to at least be an amusing way for her to go, given its irony when viewed from the outside.
Rarity appeared much less entertained by the prospect, given her screaming.