Many hundreds of years ago, Equestria wasn't the harmonious, peaceful place that it is today. Rather, it was ridden with prejudice, destruction and crime, and not a single pony, rich or poor, was safe from the chaos of the broken world surrounding them. Pegasi and unicorns detested the company of earth ponies, and alicorns themselves were not an uncommon sight; however, coming across an alicorn whose views on other races were more than low was certainly a nigh unheard of situation, as they were spoilt rotten from birth, treated as if they were gods and goddesses. It was common knowledge that if you crossed the path of royalty, you and your entire family would regret it for generations to come.
Ponies say that there's an exception to every rule, and maybe that's true. Maybe it's utter nonsense. However, there were two mares, born into the richest family Equestria had ever seen and most likely will ever see, who appeared to be the opposite of a stereotypical alicorn in those dark days. Young Celestia and Luna were princesses, born with the powers of the sun and the moon respectively, and calm, loving ones at that; the two weren't at all spoilt, and rather than using their extraordinarily strong powers for their own gain, they assisted others; be they pegasus, unicorn or earth pony, the royal fillies didn't care. They were heralded throughout the land as the two mares whose duty it was to end the dark times that Equestria was suffering to and bring light to everypony, far and wide, by way of their immense powers.
And so it came to be that the fillies' parents stepped down from the throne, and though they were young, Celestia and Luna were crowned as the new reigning rulers of the land, juggling their royal duties with their educational ones. Young Princess Celestia was tasked with raising the sun in the morning and lowering it at night, and Princess Luna was given the job of raising the moon at sunset and lowering it when morning came. Together, they introduced a new-found feeling of peace to the ponies of Equestria, learning all the while what it meant to be rulers and how to keep the peace without it once again being utterly destroyed by chaos.
On the opposite side of Canterlot from Celestia and Luna's royal castle, a large, black brick structure stood, seemingly overridden with the cocoon-bound offspring of giant insects, as the regular earth pony or pegasi would assume as they passed over it, blissfully unaware of what the castle held within its walls. A unicorn or alicorn, on the other hoof, could barely even pass by the castle without picking up on the strong taste of changeling magic, signifying that whatever called the place its home was indeed insectile, but not in the way that a non-magical creature would assume. Changelings dwelled within those walls, black, hole-filled creatures with a taste for love and no rightful place in Canterlot. They would one day take the love of everypony in Canterlot, maybe even the whole of Equestria, the magical pony would assume. They would report their findings to the princesses, who in turn would assure the pony that the changelings were just as safe as any old pony.
And that's where the story starts off.
One day, a young earth pony mare was out for a walk to the farmers' market, carrying her crops in two baskets hitched to her flanks and walking with a spring in her step and a gleam in her eye. Celestia's blessings had quite obviously been with her this year; her crops were healthy, and she and her family almost didn't have to work in order to assure that they thrived. The mare's mouth twisted into a smile. Almost. She recalled vivid memories of her brother tripping and falling over a patch of what was, until then, looking as if it was a small hill. It took the remaining members of the family a couple dozen seconds to remember that what lay on the other side of the hill wasn't just dirt, but precious farmland, and as they rushed to her brother's side, they were more than annoyed to find a patch of dirt in a stallion-like shape where the crops had been squashed flat. The family, of course, had less crops to sell, but it was more than made up for by their quality. Glancing back at her crops, the mare nodded. Yes, she'd probably fetch at least triple the normal price for them. They were as perfect as you could get, what with her family's limited access to quality farm equipment and her brother nursing a throbbing headache during the entire harvest.
A shiver ran down her spine like the claw of a timberwolf as she passed the mysterious castle. The mare had a horrible fear of all things with more than four legs, and so the cocoons and the quiet buzz of wings more than unnerved her. Her steps sped up slightly as she swore she picked up a shadowy figure in her peripheral vision; but as she turned, nopony- or nothing- was to be seen. She grunted and turned back to the path ahead of her, focusing on her journey rather than whatever was in the castle.
Suddenly, the mare swerved around. There it was. A black figure, hovering in mid-air, translucent, bug-like wings flapping at great speeds. Its eyes were a light green, and completely unlike those of any pony she'd ever seen, as the pupils were slitted and even what was meant to be the whites of the creature's eyes were a light green. And yet, it was unmistakeably a pony, or at least, it had the body of one, though it had its differences. Four legs. Furred ears. Mane and tail. It was smiling. That meant it was sentient, not part of a hive mind like she thought most bugs were. It was looking at her, staring her dead in the eyes. The mare started to sweat as her heart rate picked up and she began to turn back, to run to a place where other ponies were, to find somepony to help her. She began at a slow, steady pace towards Canterlot, all the while keeping her eyes trained on the creature. If she could get to the castle, she could get Celestia and Luna's help. She could get them to save her from the horrible creatures. As soon as the mare was in a position where the creature was out of sight, she began to run as fast as her legs could carry her, thankful that a life of farming had strengthened her legs to a point where she was going at a speed where she was confident that nopony could catch her unless they wanted a good chase first.
The mare sprinted all the way to the royal castle, not stopping to converse with any mare or stallion she passed on her way. She was fearing for her own safety, and that was reason enough to ignore her friends. Celestia and Luna had dealt with evil creatures like this before, and she was confident that they could again. What's a small, bug-like equine creature to a pair of tremendously powerful princesses who had, time and time again, sent creature after evil creature running for the hills? The castle came into view, constructed on the side of the one of tallest mountains in Equestria. The mare gasped as the noticed a blur of dark blue circle the castle before landing on the balcony, gazing through an ornate telescope. "Luna," she whispered in a voice raspy from ten straight minutes of running at top speed. The moon princess was right there. The earth pony skidded to a halt at the base of the castle, which was protected by two of Celestia's royal guards. As they noticed her, they promptly raised their spears and crossed them over the entrance, effectively blocking the mare's path to the princesses. She sighed frustratedly, and attempted to explain what had happen to the guards, who were, in turn, confused by the stuttering of the mare, constantly interrupted by large intakes of breath and coughing.
"Need... Celestia and... Luna..." she managed to choke out. The guards glanced at each other, seemingly conversing with their eyes alone, before uncrossing their spears, allowing the mare to pass. She rushed past them, not bothering to thank the stallions as she her mind focused on locating either princess, blocking all other thoughts in her frenzy. "Princess Celestia!" she screeched, her voice cracking. "Princess Luna!" She swivelled her head, searching frantically for any signs of the two princesses.
"What is wrong, young one?" a voice echoed from behind her. The earth mare spun around, and sighed with relief as she took in the form of an alicorn behind her. Her fur was dark blue, and her mane a lighter shade of the same colour. Her eyes were a light turquoise, and she wore a collar of a black metal of some sort with a silver moon imprinted onto it, and a crown of the same material. It was Princess Luna, and she was talking to her. The earth pony began to stutter and trip over her words as she tried to speak as fast as she could.
"O-Oh, well, it's, uh, a long story, really, but I need your help, and- and--"
"Help, you say? This isn't about that castle, is it?"
"W-Well... yes and no."
"Pardon?" Luna tilted her head.
"Well, I saw something weird. Like a pony, but... not," the earth pony choked out, her body shaking violently. "Kinda tall, around your size, and it was looking straight at me and grinning... It had bug wings. And holes in its legs and mane." she described the creature, waving her legs around, narrowly avoiding one of her hooves colliding with the moon princess. "... and... and fangs!" She bared her teeth and gave a convincing snake-like hiss. "Like a snake! But also like a bug! Like... a bug-snake hybrid!" The mare stopped talking and took a deep breath, still panting. Luna's eyes seemed to have glazed over. "Princess? Princess Luna? Are... are you alright?" The princess didn't reply. Instead, she turned tail and strode towards the stairs, urgency in her eyes.
"I need to speak with Tia," her voice echoed out across the hall. "Guards," she called out. A group of around a dozen batponies raised a hoof to their heads in a salute to the princess. "I need a group of at least fifty of you to surround the abandoned castle on the path from Canterlot to... ugh, you know, that town with the farmers' market."
"Ma'am, yes, ma'am," their collective voices boomed as they left the hall.
"And one more thing," Luna called after them. "Don't let anypony in, and don't let anything out."
