Moon dissolved her magic and took a deep breath of the stagnant air around her. She hated it, but she wouldn't have to deal with it for long. Sunny would, however. The alicorn went to the house of the young unicorn's parents and entered the room with the long table to Sunny and his parents eating breakfast.
"Sunny. I have something important to attend to. I will be leaving you behind here and returning when it is completed," she alerted him.
The stallion choked on his food and received several pats on his back from his mother in response. "What? What are you going to do?"
Moon frowned. "I'm not going to destroy an entire kingdom, if that is what you're worried about."
"Uuuh, wh-why would you think that? I-I-I never even imagined you would do something like that," the young stallion stammered. He gave the most unconvincing smile he could ever manage. "I-it's just, what if you need my help with local customs? Or if you need help translating some words?"
The alicorn looked at the sky outside the windows absentmindedly. "I've managed this far. You don't need to worry about anything. Any problems will be dealt with firmly," she threatened.
With that, the mare moved to leave the house, but Sunny was stubborn and jumped in front of her.
"I should come with you anyways. You know, just in case," he insisted.
"Goodbye, Sunny," Moon said sternly.
In a flash, the alicorn was gone, leaving Sunny doubly worried.
"Gah!" the changeling blurted.
It had been hiding out on the outskirts of the town atop one of the slabs surrounding it.
"Take me to your hive," Moon ordered.
The changeling gulped, nodded silently, then quickly took to buzzing into the sky. Moon experienced a twinge of annoyance. Once again she had to be led around by somepony else rather than be able to travel on her own. During the moments she felt the most trapped in her own moon she often reminisced about why everypony liked her sister and why her sister had them tow her around on her cart. She and Moon were both more than capable of flying or teleporting to any destination they so chose. She wasn't certain, but the living alicorn believed it was to make the ponies feel useful. Celestia and Luna had done everything to aid them in their growth of Equestria and its people, but nothing was ever requested in return. It was their persistence that caused the sisters to give in and start making things for the ponies to do in thanks, which in turn caused them to inadvertently become royalty with their own castles and guards and diplomatic representatives.
Moon was broken out of her thoughts by a strange, floating material in the sky. It looked like a bubble distorting reality around it. Patches of flat, gray squares would appear around it at irregular intervals and remained facing Moon regardless of the angle she viewed them at.
"What is this?" she asked the changeling.
"Changeling portal, for escaping. We'll arrive at the hive."
Moon tilted her head to the side. "Does it work both ways?" Energetic nodding answered her question. "Then go through it first," she commanded.
The changeling looked at the circle, then the pony, then the circle again, and shrugged. It casually flew into the circle and vanished. Moon scanned around it to check if the changeling had become invisible, but there was no trace. In fact, the mark Moon had placed on it still existed, but it was a vague presence. Not one to be tricked again, the alicorn wreathed herself in multiple spells of protection to protect her from forced teleportation, immediate magic damage, mind-altering spells, and more physical protection.
"These would have been helpful against my sister's ghost..." Moon lamented.
Nightmare Moon took in a deep breath and entered the weird circle. The trip was mind-boggling. It was like being torn and sown back together thousands of times per second, and every resowing felt 'wrong', and time crawled along in this hellish abyss. Every second almost felt like a month went by. A weaker pony would have gone mad from the sensations, but Nightmare Moon had weathered worse. What was a few months of a minor inconvenience to being trapped and unable to move in darkness for ten thousand years?
When she finally exited the hole, she landed with a thud on uneven ground. She took several seconds to catch her breath and regain her bearings. The first thing she was able to notice was the ground she was standing on: White stone bricks, or what was left of them. The platform Moon was standing on had been cracked in several places and were tilting away from the central crack. To her astonishment, the portions to her right looked like they had melted.
The mare cracked her joints when she stood up and gazed at the area around her. It was bizarrely bright like only white light existed in this part of the world. It was almost impossible to see anything clearly, but Moon was able to see the remains of a white stone castle built into the base of a mountain. It, too, was tilting to the side with the added bonus of sinking into the ground. The mountain surrounding it appeared to have been heavily damaged, and several chunks had been ripped out forcefully and aggressively. Before she could take in more, Moon was wrapped in a sticky, black material and dragged almost instantly towards the mountain then liberated just as quickly.
Her horn was glowing aggressively when the changelings immediately flew back and grabbed the walls and statues around. Despite the multitude of holes in the walls and ceiling and the extreme damage to the stone, the area was almost pristine. Two statues flanked a path leading deeper into the mountain. Both of them were as tall as the doorway which was, itself, big enough for an adult dragon to enter. The statues were missing their heads, signaling them to have represented one or more alicorns.
Moon bared her fangs at the changelings hiding away in the nooks and crannies of the darkness free from the outside world. They hid away behind many pillars. Some preferred to look at their guest through the gaps in the walls and even the doorways where rotten, blackened wood hung weakly.
"You summoned me here," Moon started. "Show me to your queen or I'll fry all of you and destroy this hive," she threatened calmly.
"I would rather you didn't do that, Nightmare Moon," a regal voice asked calmly.
Moon turned around to see the changeling she had marked hiding behind a much taller-looking changeling. They both walked towards each other and stopped mere inches from each other's muzzles. Their scowls made the terrified bugs tense, but no pony had moved.
"The changeling queen, I presume?" Moon said.
The queen lowered her head slightly in acknowledgment. "I am Queen Hepetia."
Her body was thin and comprised of black chitin with several holes going through it. One of them went from the left of her chest all the way to the right of her back and through her wing. Her mane and tail were autumnal shades of orange, brown, and red and resembled algae more than anything. Said mane draped over her horn, making it seem like its sharp point had pierced through a flat bed of seaweed. It was crooked and misshapen and twisted into a circle twice: Once just a few centimeters from the base of her skull which bent it to the left before a second made another rising ring that twisted it back to the right where the tip rested perpendicular to the right eye. Hepetia looked stoic and unflinching in her expression despite her gaunt appearance. That said, despite standing her ground, the changeling's bloodshot, yellow eyes made her look sickly and weak.
"You caught a changeling of my hive in a snow city in the mountains and demanded to speak with me," the queen continued. "Why is that?"
Moon felt kindred with this bug despite herself. She had to suppress a grin that was trying to grow in the corner of her mouth. "If the tales of my time are to be believed, then you already know who I am beyond my name and what has happened."
Hepetia frowned. "Tales of the changelings?"
"Your skills of subterfuge and transformation magic were legends in my time, such as that no pony believed any of your kind were real."
There was a long silence before the queen responded with a menacing smile. "Yes. I know of you, Princess Nightmare Moon, also known as 'The Mare in the Moon': Alicorn of the night sky." She turned her back and walked towards one of the statues. "Sitting, headless giants. That's what my hive knows you alicorns since history saw fit to invert our legends."
Moon raised a brow and looked around. "And yet you are back to hiding away." She placed a hoof to her temple and groaned. "Still. I believe your skills would be highly invaluable to my needs to retake Equestria and restore it to its former glory."
Hepetia scoffed. "And why would the changelings help you in any way? You have nothing we could want that we can't already take."
Moon smiled. "Well, another part of your legend is that changelings are always starving," she stated dismissively. The queen's head turned instantly to the side to have a better view of the alicorn. "Why, imagine if somepony had control of an entire country, knew where the densest population centers were, and could categorize them by the most 'loving' moods each of them had." She sat down and checked her hooves for damage. "Well, such a pony couldn't exist, so I supposed I wasted my time here. I'll be returning through that hole of yours and resuming my pl--"
"Wait!" Queen Hepetia commanded. Her booming voice startled the surrounding changelings who started fumbling in place and clicking. "You would let us drain your ponies for love?"
"To a reasonable extent that they are not harmed, yes," Moon confirmed.
"Why?"
Moon growled and dug her hooves into the ground. "Because I have had ten thousand years of contemplation. I have learned that my goals can't simply be attained by sheer force of will." She snorted in bemusement. "Or just force. My first vassal was murdered within my own city, and I intend to find them and rip them to pieces with my magic in return."
The changeling queen nodded. "A far cry from the hyper-aggressive goddess I was told about. Well, let us have a walk around my hive while I contemplate the benefits of cooperation between us: A queen and a princess."
"I plan to retitle myself as a queen," Moon said quickly. Her eyes had begun to glow, but the snarky grin of the queen did not change. "Princess is a leftover title from the days of my sister."
"A sister? Interesting," the queen commented absentmindedly.
The corridor that Moon had seen was, in fact, a bridge, and it opened to the blinding lights from outside, and she had to shield her eyes from the pain they caused. "How is there light in here? There was no opening outside? How did you bugs create this?" she asked.
Hepetia chittered angrily at the title of 'bug', but did her best to keep her composure. "We didn't make it. We just found it by accident one day and took it as our new home. It's an anomaly of magic that protects this place. No pony but us are able to come here voluntarily. Any other creature tends to be shifted about haphazardly, almost like forward becomes backwards and every other possibility."
"Then how did you get here?" Moon questioned with her head held high.
"By accident. It's rare but sometimes whatever this light is backfires and let's you reach the castle, as my grandmother learned when looking for a new home." She scratched her chest. "She was a stubborn mare. That leaves the few that do get in."
"And what of them?" Moon asked. She was met with the queen looking straight at her with an unsettling, massive, toothy smile. "I see."
Changelings were everywhere, which Nightmare Moon found befitting. Some gross, organic mounds would be spotted here or there, but the castle itself still seemed immaculate despite its damages. It was clear to the alicorn that this place had been fought over several times, but whomever had lived here still had long since died or simply didn't want to inhabit forgotten ruins. The light, however, was still a great mystery she couldn't solve.
"I've noticed that this castle is surprisingly clean. I thought you would have thought it more valuable to find a location untouched by the battles of the past and install yourselves there," Moon said.
"We have lived here for a long time. Is it not necessary amongst the other races to clean their homes?"
"True...but I still cannot understand this place. I'm surprised you can navigate it so easily."
The changeling cracked her neck several times and looked up a flight of stairs built along the walls of a square tower. "We have had plenty of time to explore, although some scouts were not fortunate," she said dismissively. Both creatures shuddered. "And we know when something unwanted has entered this castle."
The two equine leaders looked around frantically in an attempt to trace the source of the disturbing sensation. Whether they managed it or the presence decided to let them find it, the two equines raised their head to see, at the top of the tower, an unknown figure contrasting with the weak light illuminating the top floor it stood at. Whatever it was, it was staring down unblinkingly at the equines with giant, prominent eyes. It was very easy to see the scelera and the shrunken pupils accentuated by the lower eyelids raised up in a rictus the two equine creatures couldn't see but could feel.