Once upon a time, in the magical land of Equestria, there were two regal sisters who ruled together to spread harmony and friendship through all the land. To do this, the younger used her alicorn powers to raise the sun at dawn, and the elder brought forth the moon and stars to begin the night. Thus, the two sisters maintained balance for their kingdom and their subjects, all the different types of ponies.
But as time went on, the younger sister became resentful. The ponies cherished the shining stars and moon of the night her elder sister created, but took for granted the light of her beautiful day. One fateful night, the younger alicorn refused to lower the sun to make way for the dusk. The elder sister tried to reason with her, but the envy in the young one's heart had transformed her into a fiery beast of wrath: Sunflare Scorch! She vowed that she would blaze the land with eternal daylight!
Reluctantly, the elder sister harnessed the most powerful magic known to ponykind: the Elements of Friendship! Using the magic of the Elements, she defeated her younger sister, and banished her to a distant realm beyond the sun. The elder sister took on responsibility for both night and day, and harmony and friendship have been maintained for generations since . . .
Starlight Glimmer looked up from her book. "The Elements of Friendship . . . where have I heard of those before?"
Just then, the front door to the Golden Oak Library opened and slammed. Starlight looked over the loft railing to see a purple furball, a bushwoolie, scampering up the stairs.
"Starlight! Pinkie Pie's throwing a huge party for Winter Night Festival Eve!"
"Winter Night Festival Eve?" Starlight raised an eyebrow. "I didn't know there was such a holiday."
"Well, you know Pinkie," the bushwoolie said with a shrug. "But anyway, everyone in Ponyville's going to be there! Can we go?"
Starlight sighed as she began to scan the bookshelves. "Wishful, you know we don't have time for that sort of thing."
"What about that book club you host every Tuesday? Isn't that that sort of thing?"
"That's different! Book club is a meeting of intellectuals to discuss the literary merits and attributes of the great Equestrian novels, not just some wing-ding get-together! Now, where's the Encyclopedia of Equestrian History, again?"
Wishful's shoulders slumped. "Top shelf, third column from the left," he sighed resignedly.
Starlight used her magic to levitate herself to eye level with the encyclopedia, then pulled Volume E-F from the shelf.
"Elements . . ." she muttered as she telekinetically flipped the pages, all while still hovering in mid-air. "Aha! Elements of Friendship . . . See Shimmering Sun Spot?"
"Shimmering Sun Spot?" Wishful echoed. "Isn't that an old pony's tale?" Without answering, Starlight removed Volume S-T and scanned through it until she found the entry.
"Shimmering Sun Spot. A distinctive marking on the surface of the sun, mythologically explained as the remains of a portal to another realm, which was used to banish a wrathful monster who attempted to conquer Equestria. Ancient legend tells that on the shortest day of the thousandth year, the horizon shall reopen the gate, and she shall return to bring eternal daylight."
Starlight gasped. "Wishful, we need to go to the palace now!"
"The princess isn't there right now," Wishful responded. "She's in Canterlot on royal business."
"Then we'll have to write to her." Starlight lowered herself to the ground. "Take a note, please, Wishful."
Wishful nodded and scurried to the desk to grab a paper and quill.
"My dearest teacher," Starlight dictated. "My continuing studies of magic have led me to discover that we are on the brink of disaster! For you see, the mythical Shimmering Sun Spot is in fact the portal of Sunflare Scorch, who is soon returning to Equestria to bring a fiery eternal day! Something must be done to ensure that this terrible prophecy does not come to pass. I await your quick response. Your faithful student, Starlight Glimmer."
Wishful signed the scroll. "Done!" With that, Starlight used a teleportation spell to send it to Canterlot.
"Are you sure about this, Starlight? After all, the princess already has her hooves full with the preparations for the Winter Night Festival tomorrow, doesn't she?"
"That's what's so urgent," Starlight replied. "Tomorrow is the thousandth year of the Winter Night Festival, which is the longest night and shortest day of the year! It's imperative that she knows of the prophecy immediately!"
"And you think she'll take you seriously?"
"Why wouldn't she? In all the years that she's been my mentor, she's never once doubted me!"
With that, a magenta flash appeared between them, revealing a shining scroll.
"See? I knew she would want to take immediate action!"
Wishful unsealed the letter and cleared his throat. "My dearest and most faithful student Starlight, you know that I value your diligence and trust you completely . . ."
"What did I tell you?" Starlight beamed.
". . . but --- from one bibliophile to another --- you really should get outside and take a break from those books!"