Far away from the party in Ponyville, in the royal city of Canterlot, Princess Luna stood regally as she looked over the nation from her tower. The sun was slowly descending toward the horizon and many of the ponies would soon be heading off to bed. She felt a warm presence make itself known as it entered her chambers, for this was none other than her dear sister, Princess Celestia. "Fare thee well this evening, our dear sister. Hast thou finish preparing for the end of thine day?"
Celestia gracefully sauntered up to her younger sister and gently nuzzled her, "I'll finish putting the sun to bed in a moment. How are you doing, Luna?"
"We have rested well enough, we only await for thee to finish thine duties for the day before we take charge of the night." Luna stated in a professional matter.
Celestia resettled her shoulders as she looked down at her younger sibling, "you know that's not what I meant. Luna," she said tenderly. "How are you doing?"
Luna gave out a long sigh, this wasn't the first time she asked this. "We are still adjusting, dear sister," Luna said with more reserved tone. "One can not be expected to adjust so quickly after a thousand year absence. The world is nothing like that which we left and we don't see ourselves acclimating so easily. How fares thine student? We doubt thee will ever stop fussing over her simply because she now shares a title with thine own self."
Celestia gave a tired breath, whether it was from the burdens of the day or having to watch Twilight adjust to her new role, she wasn't really sure. "She's been having it rough ever since the court drew their attention to her. I knew they would but I wasn't expecting the waves of suitors to start coming after her so soon."
"It was probably for the best that she returned to her home in Ponyville," Luna approved. "These last few nights have found her plagued of fewer dreams involving said suitors. Although," she looked at her older sister, "thy nephew, the self proclaimed Prince Blueblood, seems to be at the forefront of her mind when it comes to suitors."
"Oh?" Asked Celestia, a bit confused. "I was under the impression that she didn't care for him."
"At the forefront of her mind regarding stallions she has no interest in and would rather they cease their advances," Luna said with a small snicker. "Really sister, why dost thou continue to suffer such an insufferable nephew."
"You know Luna," retorted Celestia. "Technically he's also your nephew as well."
Luna scoffed at this, "We refuse to accept him as kin when he finds himself some fifty generations removed. Besides...We did not care much for his ancestor either."
"Neither of you seemed to care for him all that much..." Celestia started to say.
"Sister!" Luna flared her wings as she slammed a hoof down with a scowl, the cracking stone reverberating through the room. "We hope that thou are not treading upon forsaken ground!?"
Celestia winced before bowing apologetically, "forgive me, Luna. I meant no offense."
Luna took several rapid breaths before she managed to regain her composure, "nay, it is us who should be sorry for lashing out. It was many years ago and nothing we do now can change the past. It would be best to, how the common folk say it, let bygones be bygones. Regardless, we fear it will continue to be a sensitive topic for some time. Alas though, dear sister," she looked towards the last rays of the setting sun. "The time for night approaches and we have duties to attend to. We shall see thee upon the morn."
"Have a good night, Luna," said Celestia as she turned to leave. "I'll see you in the morning."
Luna stepped out onto the balcony, her horn wrapping itself in a soft blue aura as she reached for the moon beyond the edge of the world. Gently and ever so slowly, the pale orb peeked over the distant horizon and lifted into the night sky, offering calm rest and subtle reflection for all who gazed upon it.
The first of her duties resolved for the evening, she closed her eyes and reached out with her mind for those who sleep and dream. For with every pony that has a dream of peace and joy, there will always be the ones plagued by nightmares.
Luna made her way through the astral plane, for it was within this space that passage to the souls that slept within the kingdom were connected. The Princess of the Night could easily enter the dreams of these ponies as easily as walking through a door.
She found herself visiting a few of the locations that she would often visit on a regular basis. Usually that ended up being many of the young colts and fillies throughout Equestria and the many fears that would often plague them. Why just now she had, for the third time this week, consoled a little pegasus filly named Scootaloo who kept beating herself up over not being able to fly. Aside from her, there was a lot of young ponies that fretted over ever earning their cutiemarks. There were far many more of these than the self proclaimed cutiemark crusaders that worried about finding their special talents, even if they were by far the most enthusiastic fillies she had seen in a while trying to earn their marks.
It wasn't just the young that struggled with their troubles, even many of the adults had problems that would follow them into their sleeping minds. A lot of them, too many of them, worried about things like money, but you'd always find ponies who's worries lay more with relationships. Whether it was just the desire to get along with their peers or someone that they may fancy pursuing a relationship of the more romantic nature. Something that had plagued their newest princess, Twilight Sparkle, and her dreams in recent days.
Luna sighed as she traveled through the dreams of that night, her mind racing through her own memories. Memories of a more personal nature. She once had some pony she was close to before... well... he would have died many centuries before her return from the moon, if the politics of old Equestria hadn't done him in, then old age definitely would have.
She steeled herself as she continued her nightly duties, she refused to let her past continue to torment her. Even if it was really hard at times.
She was about to approach the passage into Twilight's subconscious when she felt an overwhelming presence begin to push down on her. To say it felt dark and foreboding would be an understatement as the amount of pressure it was emitting felt like it could shatter solid stone.
Luna turned away from Twilight's subconscious, she would have to fend for herself tonight, as she pursued the new sensation through the astral plane. It took some time to hone in on where it was coming from. It wasn't like the malevolence she felt was faint by any stretch of the imagination, but instead it was like it was being shrouded by something. Whatever that something was, she only dreaded to think what it could be.
The pressure grew ever stronger as she felt herself draw closer to the source of the disturbance. She felt like she might soon collapse from the pressure when she found herself standing in front of a set of a very large oaken doors. Now there was several things strange about this. Doors did not usually appear in the astral plane on their own. She usually made the entrances appear as doors if she had to help a pony out on a more personal level since it helped them cope with how she was able to move in and out of their sleeping mind. The only other way a door would appear is if the mind it belonged to erected it themselves. This door in particular went one step further as it was both far larger than it would normally appear and it was heavily engraved with a multitude of runes. Usually that would indicate that the mind behind it was a powerful spellcaster or something much worse.
Her sister needed to know about this, but first she needed to find out more. She needed to find out the nature of whatever threat this may present to Equestria.
Luna rested a hoof against the door with the intention of pushing it open. Her hoof had only rested on it for a moment when she felt a sharp jolt run up her leg, numbing it in the process. She struggled to pull her leg away but found herself stuck fast not only to the door, but rest of her limbs were stuck to the non-existent ground in front of the door.
The runes in the oaken door began to glow with a vicious light as shades of green and purple began to pulsate off of them. Luna continued to struggle with her stuck hoof as the door began to slowly open. When the smallest amount of light broke through the crack of the door, she found her hoof break free of the door only for it to be snapped to the ground to join the rest.
The door swung inward with the sound of grinding metal, which just added to the list of things that didn't make sense about the situation. The gap in the door creaked wider and she found a set of deep red irises gazing out at her. The eyes seemed to grow closer as a space beneath them began to sizzle and crack as the darkness that made up the creature's body split to reveal a maw lined with razor sharp teeth. The muzzle that housed those teeth reached for her even as thick viscous fluid dripped from the teeth and splashed against her coat, leaving a burning sensation that cut down to the bone.
Luna was about to scream when she felt something pierce her body. She looked down to find herself skewered with long purple claws, she started to go into shock as the maw rushed in and bit deep into her neck. The beast lifted her from her cemented position and, paying no mind to the stuck limbs of the lunar princess, practically tore her from where she stood, leaving her with the sensation of flesh tearing and joints cracking as the creature pulled her inside.
Luna woke with a start in her bedchambers, wait, that isn't right. Her bed wasn't this solid. Nor were her bedchambers this light as she felt the light of the sun all around her. She struggled to her hooves as a phantom pain rushed through her body. Why was she feeling so sore.
As her mind caught up with the rest of her, she remembered the events that had just taken place at the door. She felt a shudder rush over her as she quickly inspected herself, only to find herself whole. She sat there for a moment, shivering on the cold crystal ground with her forelegs wrapped around herself as she waited for the terror to pass that was causing her to seize up.
While she still sat there shaking, she took in her surroundings. The crystal ground had seemed out of place in Canterlot, but as she took in the space around her, she found that more than just the ground was made of crystal.
Tall buildings lined the road hewn in the many colors of the rainbow. Each home appeared to be made of a singular crystal crafted into a shape the resident desired. A few larger buildings could be seen here and there, likely businesses and other facilities. All the roads she could see appeared to converge on a large structure in the center of the city, a palace also made of crystal.
She was in the Crystal Empire.
How was she in the Crystal Empire?
She shakily got to her hooves and attempted to teleport herself to Canterlot. It would leave her exhausted to use so much magic after the night she just had, but her sister needed to know about the threat they faced even if it left her too tired to stand afterwards.
Luna started to cast the spell that would send her home only for the magic to quickly unravel itself and fall apart. That was odd. She tried again only to face the same result. She tried a few simple spells, only to find her magic out of reach, which was rather worrisome.
Luna looked to the palace and started walking. Even if her magic was currently failing her, surely Princess Cadence and Prince Shining Armor could help her send a message.
She had been walking for a couple minutes when she noticed that the palace wasn't getting any closer. As someone who dealt with situations like this on a nightly basis, it didn't take long to figure out what had actually happened.
She was in a dream, she realized as she facehoofed.
Luna looked up at the palace forlornly. Wherever she was going to go, it wasn't going to be in that direction. If her magic hadn't been acting up, she could simply wake herself up. But with the current situation...
She heard some laughing down a side road. Well that was as good a sign as any on where to start looking, she thought to herself as she followed the sound. Rounding the corner, she found the source of the laughter as two little fillies played in the street. Who those fillies were though, momentarily caused her breath to catch in her throat.
It was her and her sister, as simple unicorns. As they would've been before their ascendance.
"Precious aren't they?" Came a deep, dark voice from beside her. "Pity they had to grow up."
Something in the voice sent chills down her spine. Whether it was the cadence of the voice or the sheer malice behind the words. Luna slowly turned to find the owner of the voice, only to find herself face to face with a tall ashen unicorn. He wore a flowing red cape and armor around his hooves. A crown adorned his brow as it kept the flowing black mane pushed back behind him. Sticking out of the crown, where a normal unicorn's horn would be, was a long curved red spike. His red eyes looked down at her, purple smoke pouring from the edges.
"King Sombra!" She gasped as she tried to back away.
"Well," he said with a tone of mirth as he towered over her. "Somepony remembers me."
"What are you plotting this time, you fiend?!" Luna roared at him.
"The same thing I've always been plotting, my dear sweet princess," the way he said those words made her feel sick.
Sombra's eyes narrowed into a scowl, "I want my kingdom back!" He took a few more steps toward her, "I want you and your sister to pay for banishing me into shadow." He was almost on top of her at this point. "And what I want more than anything else, is to be free of the accursed pony that keeps me prisoner here!"
Luna swallowed hard, "you're a prisoner here?"
A sinister chuckle broke from his lips, "not for much longer, thanks to you."
"Me?!" Luna reeled back in shock. "What did we do to grant thee freedom?!"
"You stuck your neck out to feed a hungry beast," Sombra's body began to fog as shadows began to pour off of him. His limbs growing larger as he towered ever higher over her. His mouth began to warp and stretch until it became all too familiar to Luna.
"You!?" she quivered. "You're that thing?"
"Indeed," the growling voice rolled over her. "And once I've finished consuming you, I will finally have the strength to break free of this prison."
Luna's retreat was halted as her hooves once again found themselves fastened to the ground. The fog continued to spill out of Sombra and form the creature in front of her, its maw stretching far wider than it had before as it extended around her. She felt tears run down her face as the hot, sticky breath washed over her face. Every part of her being was in a panic to escape, but it wasn't enough to actually do so.
Just when she though the end would come, two little lights came bounding at the large creature and barreled straight into it, causing the beast to roll across the street and smash into several of the crystal houses.
Luna looked to find the two fillies standing next to her, a look of determination on their little faces as they stood next to her.
"Are you ok, princess?" The two foals asked in unison.
"I...I think so," Luna was heaving for every breath she could get. "My legs though..."
The two fillies turned their horns on her and lit up the ground around her hooves. They started to tingle as they worked and she soon found herself able to move again. "You have my thanks," She said.
"Save your thanks," said her little rescuers. "It's not safe for you here."
"But my magic..." She panted as she tried and failed to light her horn again. "How do I get out?"
"We will guide you," the fillies turned to run. "Hurry!"
Luna chased after them as they ran down the street towards the palace. Whatever was keeping her from getting close to the palace before wasn't holding her back this time. "Was that thing really Sombra?!" She shouted after them as she struggled to keep up.
"Most of him anyway," said the sisters without breaking stride.
"What dost thou mean, most of him?!" Luna exclaimed in apprehension.
"The one defeated upon the empire's return was but a small part of what's chasing us." Their voices grew sad for a moment, "I'm ashamed to admit that some of it managed to escape me."
Luna looked back over her shoulder to see the creature lumbering down the street behind them, quickly gaining ground as it did so. "It's getting closer!" She shouted as she poured everything she had into her gallop.
"Tia!" Shouted the little Luna.
"On it!" Responded the little Celestia as she turned into a skidding stop, just before leaping back the way they came.
As Luna watch the younger version of her sister leap through the air, her body began to shimmer until the little filly was replaced by a pure white lance that continued its trajectory. With a resounding crack, the air around the lance shattered and sent large chunks of the crystal ground flying through the air in all directions.
"Don't stop to look! Keep running!" Shouted the remaining little filly as they approached the palace. "That'll only slow it down and we're almost there!"
Luna was lead into the space under the palace by her younger doppelganger as they came to a stop in front of the Crystal Heart, the legendary artifact of the empire. She looked around in a panic, "where's the exit?!"
"Just a sec," said the smaller version of herself as she stared at the heart. A moment later, a long green chain snaked out of the crystal. "Grab it, that's your..." The rest of the filly's word's were cut off as a large claw came down on it, causing the apparition to disappear into a puff of smoke.
Without further hesitation, Luna leapt for the chain. As soon as she had a hold of it, she felt herself being roughly pulled through the air, the beasts claws just barely missing her hind legs as she was sucked into the Crystal Heart.
"Luna! Luna! Luna!" Came the desperate shouts.
Luna's eyes fluttered open as she heard her name being shouted, a set of hooves pressed at her shoulder as they tried to shake her awake.
"Tia?" Luna's tears ran freely down her face as she rushed into her sister's embrace. "Oh sister!" She cried out, any regal tone she would normally use gone from her voice. "I... I was so scared!"
Celestia, sensing her sister's distress, pulled Luna into an embrace and wrapped her snow white wings around them like a large blanket. "Lulu," she called her sister as she offered her support. "You had me so worried. The moon hadn't moved in so long and I started to worry. I found you in your chambers collapsed and drenched in sweat. What happened?"
"Something... Something's out there... Something terrifying." Luna began to tremble as she felt her sister hold her even tighter.
"Luna," Celestia said calmly. "It's already supposed to be morning. If we delay it much longer, the ponies will start to worry."
"Can... Can you do it please?" Luna pleaded between sniffles. "Just for tonight at least. I don't think I could. Not after Sombra almost..."
Celestia's eyes grew wide with shock at what she just said, "Sombra? Are you sure?"
"Mmm hmm," Luna nodded as she snuggled into her sister's chest.
Celestia gently rubbed the back of her younger sister who had been reduced to a sobbing mess, however her tone was serious, "tell me everything."