"Once upon a time..."
There was a city made of crystal far to the north, where the noble Princess Mi Amore Cadenza ruled over her subjects with the same love and care that fueled the magic shield the captain of her guard and herself powered to keep the north's eternal winter at bay.
In this city were many ponies of various trades who brought the streets to life. There was the town crier, a bubbly mare who could always spare a smile and a helping hand. She excelled at her job for there was never a time when her chatter ceased. A farm-mare grew crystal apples with her kin in the outskirts of the city and prided themselves on their integrity. Rainbow Dash was the guard's second in command, and never backed down from a fight especially if it was her friend, the local dryad whose gentle nature left her unable to assert herself around ponies.
In the castle, the captain's little sister, resided. She was a scholar who rarely ventured out and preferred to practice her magic in private. Ponies thought her clumsy and a few even made underhand remarks that she might not amount to anything and considered her noble lineage both her only saving grace and a shock for someone who dressed in patched mantles and wore ink-stained gloves.
It was their loss, her mantles were very cozy.
Next to the princess herself the most well-known pony of the crystal city was the Lady Rarity, a mare whose smile was said to be as bright as the diamonds that adorned her gowns of silk as fluffy and white as snow. Her favors were worth more than gold, and her generosity was admired by all. Parents could only dream that their foals would end up as beautiful and mature as the Lady Rarity, who despite some of her shortcomings could prove herself to be the epitome of charity.
It was inevitable that news of such a mare would travel to the neighboring kingdoms, like Equestria which was to the south. Word of her soon reached the ears of Starlight Glimmer, a miserly sorceress who lived in the city of Canterlot. Starlight was left bitter at the loss of a friend, now a wizard-in-training at one of its magic schools. Starlight did not try to find her friend and talk to him, but instead declared that he had betrayed her despite his generous invitations to the academy where he now resided. She had been trying to get her cutie mark- an emblem of one's destiny that upon appearance was often sewn onto garments-in magic too!
How dare he let her fail like this, and mock her with his pity!
She, a lonely but sour creature who made no attempt to justify her actions to others, decided that if she lost somepony that she had cared for then so would this city! They would no longer have their Lady Rarity, soon that noble-mare's generosity would belong only to her and she would have a friend again and one that was equal to her!
Starlight pored over tomes of enchantment searching for the perfect spell to further her desire. The one about a cursed jewel would work perfectly! She set about working over her cauldrons, mixing bottles of varying colored formulas until she withdrew her masterpiece from the bubbling depths with a flicker of magic from her horn: there in its grasp was a crystalline heart shaped pendant of a dull black color. It was just big enough to fit in her hand, and once she found a nice chain it would do quite nicely. She had heard that the Lady Rarity did like jewelry and she had made this one irresistible.
The heart emitted a faint pulse of green and purple energy and Starlight slipped it into the pocket of her magenta suit.
...
Rarity kicked at the crystal lamppost in frustration and cringed immediately after, not just at the thought of what this could do to her designer boots but because kicking crystal hurt quite a bit.
With her other hoof she massaged the sore one which caused her skirts to swish in the light snowfall, the sparkling flakes settling down on the shimmering fabric of the same hue. She clutched her basket tighter in another hand. It was filled with fabric and thread she had recently purchased from the market. She really did hope that there would be no need to repair her boots since this was supposed to go towards patching up the jacket of her little sister, Sweetie Belle's friend, Scootaloo. How she managed to loose half the sleeve climbing trees, Rarity wasn't sure.
"Do you need a hand there, miss?"
Rarity turned around to see a pink coated mare dressed in a suit and top hat that made her look quite dapper. She had a friendly smile on her face, and looked somewhat confused.
"Oh," Rarity began, "Thank you for the offer but I am alright carrying this on my own, but what about you, darling? You look quite lost, are you a tourist?"
"Well-"
"Oh dear, if you're a tourist you must be freezing in this cold-I know it does take some getting used to-that means you'll be needing a scarf! I have quite a few at my manor that I'd be glad to give you. I was heading there anyway to do some sewing in my solar but I don't think anypony will mind if I have a guest over, now what is your name? I feel dreadful not asking about it before."
"Starlight Glimmer," the mare replied.
"Well Starlight, I'm-"
"The Lady Rarity, Gem of the North."
Rarity's hand flew to her mouth. "So you've heard of me, then?"
Starlight smiled a bit more, she looked very friendly. "Why yes, I came all this way to give you a gift, being the admirer that I am and all..."
Starlight covered her face briefly with her own hand, Rarity presumed it was to hide her probable blush. Her other hand reached into her pocket and she pulled out a pendant of a black heart on a chain of silver. That hand concealed a wicked grin, befitting the witch she was.
Rarity dropped her basket and gasped, her breath exiting her mouth in a small cloud due to the cold. "How beautiful! Is this really for me? I'm so flattered, Starlight this is beautiful, how did you make it? I can't say I've ever seen anything like it before."
Starlight winked, "Craftspony's secret."
Rarity accepted the piece, running the chain through her delicate fingers. "So you're a jeweler then? Well the Crystal Empire is the right place to find gems-"
"Such as yourself?"
Rarity lowered her eyes and looked at the heart jewel. "Really, you flatter me."
She slipped the necklace over her head and adjusted the charm so it hung perfectly symmetrical when compared to the rest of her appearance. Rarity looked like the subject of a painting, but it was hard to imagine a mare as vibrant as her fading like paint.
Rarity's blue eyes widened and she froze, posture adjusting to something even a soldier would consider unnatural. 'Did you enchant this?' was the question that died on her tongue as her irises turned green, and purple smoke curled out. There was no light in those eyes now.
She looked like a statue, cold and lifeless.
Starlight stretched out a hand gloved in spotless white. Within seconds Rarity's own hand moved stiffly into her own.
...
As Starlight fled to the southern wilderness with Rarity she caused some havoc of her own.
She knocked over a sign on a rural road, and it fell into some bushes where it remained as unseen as the sorceress and the noble that followed her.
Unable to see the sign that would guide them to the town they were needed in, an Equestrian sheriff unfamiliar to the region led the two con-ponies he had caught down the wrong road, where he stumbled on a tree root and hit his head on the ground where he was out cold.
The two unicorn stallions escaped into the woods where they constructed a shelter out of some of the flora they managed to find. In doing so, they shifted the foliage guarding a rabbit's den so it was disguised and a young white rabbit on his way home found himself utterly lost.
The rabbit wandered until he came to a wagon where a blue unicorn mare was preparing supplies for her latest show in the next town. He found some carrots among this supplies and gobbled them up before scampering away.
The mare who owned the wagon did not notice this and headed to the next town where when she failed her big show-stopper due to a missing prop. Angered by this, Trixie Lulamoon vowed to win a challenge against the path of the next pony she met and left in shame.
Meanwhile, Starlight escaped all notice and headed into the gloomy Everfree Forest where she hid the enchanted Rarity in an old castle.
...
It soon became known throughout the Crystal Empire that the Lady Rarity was missing. Princess Cadance gathered the subjects that volunteered to search for Rarity.
Applejack, Rainbow Dash, and Fluttershy-who was honestly just following Rainbow-were chosen by the princess to seek the noble-mare through their own means. The Princess of Love had thankfully received a vague tip that placed Rarity at the market talking to a strange pony none could recall correctly-had it been a tourist?
As the three set out to gather a few things for their trip Twilight Sparkle watched from the shadows wondering which would succeed in retrieving Rarity before she went back to studying manuscripts.
...
Applejack choose only her lasso.
Fluttershy brought some food to eat on her way, since she couldn't think of anything else a spirit like herself might need. She definitely wasn't going to hurt anypony.
Rainbow would bring nothing except the armor she was wearing, utterly confident she could bring one unicorn back to the Crystal Empire. They set out, splitting up at the border: Rainbow to the air, Applejack to the ground holding off the snow, and Fluttershy traveled with the aide of the few creatures hardy enough to brave this environment.
All three arrived in the land of Equestria, at differing times where they set out to search far and wide for the missing mare.
In the library of the Crystal Empire, Twilight Sparkle helped a young unicorn filly with purple and pink curls find a book on tracking spells, even though they were clearly too advanced for her.
...
First, Fluttershy came to a dirt path, where she heard a rustling in the bushes. Apprehensive at first, the noise revealed itself only to be a white rabbit who looked very tired and a bit hungry, but otherwise just as lost as she was.
Unable to resist the sight of a creature she could help, Fluttershy deterred from the path to help the poor creature.
Applejack was next to come to the very road Fluttershy had deserted. She went along much farther until she found a brown stallion with a silver star pinned to his vest getting up from the ground, looking dazed and clearly in need of the help a capable pony such as herself could provide. Rarity would just have to wait.
And so went Applejack.
Rainbow too, did not adhere to her quest. When she encountered a boastful and extremely disordinate street magician who goaded the pegasus mare into a duel that would showcase their talents Rainbow, now riled up, simply couldn't resist.
She claimed it was for honor.
It was really for her ego.
...
Back in the Crystal Empire, Twilight Sparkle fingered the cover of a book. What if three ponies weren't enough to find Rarity, would the entire guard have to be sent instead?
But why had Rarity left in the first place? She loved it here, that Twilight knew for sure.
Everypony did.
So then why would, the Gem of the North leave? Lady Rarity would never do that, even if Twilight didn't personally know the mare it was hard not to admire her the few times Twilight had talked to her at the crystal court.
Magic must have been involved...why else would Rarity suddenly desert her home? The scholar, who knew the library better than anypony who worked there, had reached her own conclusion.
If there was magic involved, she had to to help.
She gathered up a pack filled with all the books and charms she could think to bring. Food was for those who didn't spend all their time around aura, alchemy, paper, and ink, thus overrated.
...Although some snow gear could be useful. Like a heavier mantle, for example, and maybe some bracers.