Luna and Celestia had discovered a darkness slowly falling upon Equestria, one of a most ancient and powerful origin. A power that had long slumbered, hidden away in the coldest and darkest places of the world, kept at bay for untold millennia by the aura of peace and light innately given off by the elements of harmony and their consecutive bearers. This dark power was stirring from its timeless slumber however, awakened as the power of the elements that had kept it asleep for so long, dimmed. Drained in the restoration of the Tree of Harmony and the subsequent suppression of the Everfree forest. The drop in the element’s power had not been total or permanent, but it had been severe enough and lasted just long enough to allow the darkness to begin its awakening. And though the power of the elements had since been fully restored, and the aura of good renewed once more, it was no longer enough. For just as a storm churned sea is infinitely harder to contain than a still lake, the darkness had gained momentum with its stirrings, and could no longer be contained by the thin aura of the elements that veiled the land. The elements could only slow it now, in hopes of giving Luna and Celestia enough time to realize the world's peril and act.
For those who knew what to look for, there were many signs that all was not right in the world. The griffin kingdoms told of the Windigos leaving, only for them to be spotted in the deserts of Saddle Arabia of all places. Every phoenix except for Philomena had suddenly left Equestria and moved southwest across the seas they so hated. The changelings were becoming more active in northern Equestria, their raids growing bolder. The glaciers near the Crystal Mountains were cracking, leaving huge rents running across their normally smooth surface. Even the great frost dragons of the far north had awoken from their slumbers, leaving their icy mountain caves and moving south to the savannas of the zebra lands, leaving behind the great hoards they so treasured. These signs and more were a clear message, and the royal sisters had understood perfectly that all was not well.
The royal sisters had dived into the Canterlot archives, looking for answers. They scoured every book, combed through every hidden scroll, searching for a clue that would help them piece everything together, and after a month of relentless searching, the sisters finally found a clue, just a single clue, but it was enough. Hidden away in the Starswirl section, by the dawn light of Hearth’s Warming eve, the sisters had found one of the eccentric unicorns old diaries, its front covered in thick dust and its pages rendered nearly illegible by mold and mildew, but just nearly. Inside they had been able to read little because of the damage, but a few pages near the middle had weathered the years far better than the rest and they were able to read them. In those few precious pages, Starswirl spoke of a mare, a soothsayer from far away who had come to visit him. From his tone, it was clear that the unicorn hadn't put much stock in her words, but thankfully he had written them down anyway, though a few words here and there had been eaten away by the mold.
"When the winds of the north blow south and lay their icy breath upon the desert, you will know its time is coming. When skies of red and gold leave the lands of green and fly across the seas of blue, you will know the mountain of black in the north stirs again. When once peaceful air hums with menace, you will know darkness breaths once more. Whe..." it became illegible here, but cleared up once more shortly after "... bonds of the void grow weak. And when finally the claws of ice grip tight the manes of grass, you mu......ake the box of crys.......to it's door, or make your peace, fo......'s dark hand reaches into the world and its coming is nigh."
A cold fear had swept through the sisters as they read, each new line fitting perfectly into their little puzzle. They still had many questions, and the prophecy wasn't explicitly clear, but the two together had been plenty clever enough to puzzle through it. They knew what they had to do then, and they had spent the night hastily packing before contacting Twilight in the hour before dawn’s first light.
However, Twilight and Rarity knew none of this, for the sisters had a plan, and they had decided that it was far too dangerous to let Twilight and her friends be a part of it. Thus they kept it a secret, not wishing to alarm Twilight unnecessarily, for Twilight could currently do little to aid them, and if they failed, it was better that Twilight and her friends spend their last moments in blissful ignorance. So Twilight went flying off to Carousel Boutique with Spike in tow, blissfully ignorant of their impending doom.
Upon arriving, Twilight discovered Rarity and the box gone, and when she asked Sweetie Belle where Rarity and the box were, the little filly gulped and stammered nervously, quickly thinking up a lie so as not to get in trouble. She told Twilight that Rarity had gone out and taken the box with her, but when Twilight pressed the matter and asked why she would do that, Sweetie Belle panicked and blurted out the first thing that came to her mind, telling Twilight that Rarity had taken it to the jewelers to get polished. To Sweetie Belle's relief, Twilight apparently thought that was ‘just so like Rarity’ and promptly went off to find her. However, Sweetie Belle's relief quickly turned to dismay as Twilight left, realizing too late that now she would also be in trouble for lying as well, when Twilight got there only to discover the deception, and find neither Rarity or the box! The little filly groaned and flopped down on the floor, resigning herself to the inevitable, and fervently hoping that Rarity would be generous in her mercy.
Meanwhile, Rarity had finally located the pawn shop that Sweetie Belle had sold the box at, only to discover that the box had already been bought by someone else, and worse, the owner was stubbornly refusing to tell her who! However Rarity was nothing if not a resourceful mare, and using her feminine wiles, she soon had the stubborn stallion telling her exactly what she wanted to know. With a flirtatious thanks and a flip of her mane, Rarity turned and daintily trotted out of the pawn shop. Once she was out of the shopkeepers line of sight she hastily dropped her lady-like manner and broke into a dead run, heading straight for Cheerilee's house.
Rarity galloped through the back streets of town as she made for Cheerilee’s house, doing her best to avoid the more heavily populated areas so that as few as possible would be witness to her most unlady-like display. Arriving out of breath and panting, Rarity took a moment to compose herself before knocking on the door. Cheerilee opened the door with her usual smile, and Rarity sighed inwardly, relieved to see she was in. After a quick explanation of what was going on, Rarity’s relief turned to dismay when Cheerilee told her that she didn’t have the box anymore. Doing her best to remain calm, Rarity politely asked her what had happened to it. With some regret, Cheerilee told Rarity that she had bought it as a present for Mayor Mare and that the box should be with her.
Resigning herself to running around town yet again, Rarity politely thanked Cheerilee and trudged off to town hall. Rarity wasn’t sure where Mayor Mare lived, but she was certain that the Mayor would be in her office at this time of day. She consoled herself with the certainty that this entire farce would be over soon as she made her way up the steps of town hall. As she had expected, she did indeed find the Mayor at town hall, but to her growing irritation, not the box.
The Mayor informed Rarity that she had intended to display it on her desk, and so she had just dropped it off at the jewelers to be polished. After Rarity had explained the entire situation to Mayor Mare, she agreed to return the box and gave Rarity a pick up receipt for the jewelers. With a sigh and a brief thanks, Rarity took the receipt and dashed off to the jewelers. She took the most direct route she knew, and damn lady-like behavior and any who saw her, she was just eager for this fetch quest from hell to be over.
Silently praying the box would be there, Rarity stepped into the jewelers shop, looking around hopefully as the little bell sounded. To her immense relief, the box was there, freshly polished and sitting on the counter, just waiting to be picked up. She eagerly explained everything to the old shopkeeper and gave him the receipt. The aging stallion took the receipt and simply shrugged, it didn’t matter to him who picked up the thing, so long as they had the receipt. Rarity sighed with relief and picked up the box with her magic, profusely thanking the stallion for his understanding. Then she turned around, opened the door, and walked straight into Twilight, sending both of them sprawling.
With a groan and a shake of her head, Twilight got up and helped Rarity to her hooves, telling her that she had been looking all over for her and the box. Rarity muttered under her breath that it probably wasn't as hard as she'd been looking, then dismissing Twilight's plea for her to speak up with a wave of her hoof and a bit of nervous laughter, telling her it was nothing. Twilight shrugged and proceeded to tell her that she needed the box, because Luna and Celestia had asked that it be sent to them as soon as possible. Rarity eagerly presented Twilight with the box and came up with a quick lie to explain everything, telling her that she had just been getting it polished and had just come and picked it up. Taking the box with her magic and holding it before Spike, Twilight remarked that she knew this as Sweetie Belle had told her, and as the box disappeared into Spike's green fire of sending, Rarity found herself unsure whether she wanted to strangle Sweetie Belle, or hug her. Either way it looked like Rarity was in the clear, and after exchanging a few more pleasantries with Twilight, they both went their separate ways. As Rarity headed home, she finally decided to forgive Sweetie Belle for lying to Twilight, but that the filly would be grounded for a week for selling it in the first place. And Rarity vowed to make it a very bad week indeed.
When the box finally arrived at the castle, both Luna and Celestia sighed with relief, their worry at the long delay in the box's sending put to rest. Luna touched her horn to the top of the box and a dim light began to shine from the keyhole pointing north. They had their compass at last. The two sisters quickly packed the box into their supplies and set forth, going north in secret. They flew as swiftly and silently as they could, letting the light from the box guide them as they prayed it wasn't too late to stop what was coming.