Usually she'd put comparatively little stock in millennium-old legends, but this is a primary source, and the authors made some correct predictions on other matters, and the translator is good, and she double-checked to make sure the page numbers matched up so no one has been pranking her with inserted extra leaves. And the prediction is fairly dire.
And it's rather short notice.
Clarity tucks the book into a saddlebag and trots up to the main section of the palace. She can usually get an audience fairly quickly; Celestia has taken a particular interest in her since her admission to the School for Gifted Unicorns. This day is no exception. In fact, the guards usher her in even quicker than she'd usually expect.
"Princess, I have something urgent to tell you," Clarity says, mid-bow.
"Oh? What is it, Clarity?" inquires Celestia.
"I've found a prediction stating that on the longest day of the thousandth year -"
"Clarity," sighs Celestia.
Clarity grits her teeth; she's never told Celestia not to interrupt her. You can't tell the princess that. "Yes, Princess?"
"I have the utmost respect for your diligence at your studies, but you've got to take your nose out of those dusty old books now and again," says Celestia with a warm half-chuckle. "There's more to a young pony's life than studying. You're in the prime of your life, you're coming up on the end of what you can learn from school -"
Clarity stands up on all fours, no longer bowing, jaw slightly open.
"And," continues the Princess, "you need to make some friends. I worry about you all alone, you know. Weren't you invited to that party - who was it, Moondancer?"
"Yes, I was invited, but I barely know her," says Clarity.
"Perhaps the ponies around Canterlot just aren't clicking with you. You know what," says Celestia, as though seized with sudden inspiration. "I'm going to give you a job to do."
"...a job, Princess? But what about the longest day of the thousandth -"
"Clarity," says Celestia again, and Clarity shuts her mouth. "Don't you worry about it. I'm sending you to supervise the preparations for the Summer Sun Celebration. It's being held in Ponyville this year. I'll arrange a carriage for you. Pack your things, you leave in two hours."
"I..." Clarity can't really gainsay her. "Yes, Princess."
Celestia smiles.
Clarity bows again, and leaves, and packs.
-
She's in the air, drawn with her luggage in her carriage by someone in good condition for a long-distance flight - they're still working on that train line.
She steps onto the main street of Ponyville, laden with all her possessions in her saddlebags, and levitates her to-do list in front of her nose.
"Okay," she sighs to herself, peering at the first item. Clarity is pretty sure Celestia has read every book in the palace library at least once; probably she investigated the danger well in advance and dismissed it. (But Clarity will be staying in a library while she's in Ponyville, so she'll have a chance to double-check and find corroborations once she checks out the Summer Sun Celebration preparations.)
"First," Clarity mutters, "banquet preparations. Cheery Cherry Orchard."
"No. I like books, but I'm not actually a librarian. I do need to do some research incidentally, though." She starts peering at some shelves, trying to figure out what organizational system is at play here. "I'm Clarity Bell, by the way."
"I'm Blueberry! What are you looking for?" she asks, standing up. "I've been coming here practically my whole life, so I know where everything is."
"Unfortunately I was interrupted by the errand so I don't have much to go on. Key words include -" Clarity produces her current notebook. "Mare in the Moon, or, Nightmare Moon; and the Elements of Harmony." What kind of classification system is this? It doesn't seem to be arranged by author or in subject groupings. Is this literally alphabetical by title? Wow.
It is titled The Elements of Harmony: A Reference Guide.
"Oh, cool, that's exactly what I needed. Who organized this place? Is it, in fact, alphabetical by title less leading articles, or is there some nuance that I'm missing?"
"The last librarian organized it. But then she moved to Manehattan. The shelves that are alphabetical by title are because there's no author recorded for those books; if you start over there," she points a hoof, "it's nonfiction alphabetical by author, then fiction alphabetical by author that stops over there and starts again up there on the next floor, then a bunch of things that Page Turner never got around to filing properly in no particular order on that shelf way up there."
Okay. Six Elements of Harmony, only five known: laughter, generosity, loyalty, kindness, honesty. Known to whom? The unspecified author of this book, apparently. Oh, hay, why didn't the Princess listen to her? The other book said she used the bucking things. She could probably list them all, and tell Clarity where they were, in less time than it had taken to chide her and tell her to make friends. And then Clarity would at least have an idea of what to do if some disaster did happen to occur at the Summer Sun Celebration.
Oh, this book knows where they were last seen, apparently. Last known location, palace of the pony sisters, located in what had become by the time of this book's publication the Everfree Forest.
Eeugh. Clarity has heard of this forest; it is no doubt serving useful ecological purposes, but it isn't exactly a comfortable prospect for traveling through.
Celestia was unworried; the elements sound vaguely from the language of this book like they might require special status of some kind to use at all; and if they were that important Clarity vaguely doubts they'd have been left to decay or crumble or undergo whatever deterioration process applies to the unspecified material in a disused castle. So she decides they're probably not worth running out to fetch right now. She might not make it there; she might not need them for anything; if she did she might be unable to handle them to any useful effect; and they might not be all they're cracked up to be. But she feels better for having been able to consult the reference and is glad she left time for it.
"More or less. It's not as complete as one might hope, but it's probably the best thing available right now."
"I saw them referenced in a book I was reading earlier and wanted to follow up; I wasn't strongly expecting to find any particular facts because I didn't know what they were."
"Oh, I see. The book is kind of vague. It talks about how powerful they are, but not what they're for or how to use them. Not much of a reference guide, if you ask me."
"It really isn't. I don't suppose there's another book mentioning them that you've run across?"
"I can't think of one offhoof, but I haven't read every book in this library," she says. "Just most of them."
Clarity looks around the vast array of books in the library. "You must read pretty fast," she says, trotting up to the top floor where the librarian living quarters are to finally offload her saddlebags.
"I guess the library would have to stay unstaffed for quite a while to still have the position available in a few years, though." Clarity locates the disorganized shelves and scans them in case there's something else Elements- or Mare-in-Moon related but finds nothing.
"Well, you clearly know how to perform at least one librarian-designated task already, I would have spent hours looking for that book on my own."
Clarity is going to do some notebooking now until it is time to congregate at the Summer Sun Celebration.
When the time of the celebration approaches, a pink earth pony with a green mane comes to collect her. Blueberry puts her book away and trots up to her with a happy cry of, "Hi, Clover!", then follows her to the town hall.
It is crowded, the food is tasty, everypony in town is mingling, the choir stands ready, and the sky is still completely clear to allow proper viewing of the sunrise. The decorations are finished and the curtain is down to allow proper dramatic reveal. A mare who must be the Mayor is standing by it to present Celestia at the correct moment.
"Fillies and gentlecolts, as mayor of Ponyville, it is my great pleasure to announce the beginning of the Summer Sun Celebration!" cries the mayor. "In just a few moments, our town will witness the magic of the sunrise, and celebrate this, the longest day of the year! And now, it is my great honor to introduce to you the ruler of our land, the very pony who gives us the sun and the moon each and every day, the good, the wise, the bringer of harmony to all of Equestria... Princess Celestia!"
That's the cue for the songbirds, and for the drawing of the curtain.