Deep within the halls of the castle of the royal pony sisters, the returning Princess of the Night lay inside her chambers. It laid deep within the old wing of the castle, but since her return, it had been ordered to be newly refurbished, as it had been abandoned for about a thousand years, awaiting the return of it's owner.
It had been only a day's passing since the power of the Elements of Harmony vanquished the evil entity known as Nightmare Moon. The frightening being once again changed into Equestria's younger Princess, and the day was spared.
Princess Celestia, the elder of the two, sat quietly in her Throne Room, attending to her usual royal business as she does everyday. Something seemed different about her than usual, though. She seemed... happier. Why wouldn't she be? Her younger sister had finally returned after a millenium of imprisonment. She couldn't be happier.
Princess Luna, the younger, laid quietly in her bed, enjoying a peaceful sleep. It had felt good to finally be able to sleep in the comforts of her soft bed after said millenium of imprisonment inside that which she represented: the moon. But all that was over, and she did not wish to ever be reminded of her atrocious misdeeds as the dark alicorn.
Enshrouding Equestria in eternal night, frightening all of its citizens, and worst of all... hurting her one and only sister. It had pained Luna to know this was all her fault, but not of her own accord, and beyond her control. She was still worried if the ponies wouldn't accept her after all she had done, but for now, all she cared about was resting, attempting to rid her mind of the nightmares that haunted it.
But, used to being a nightmare in physical form, would she be able to experience a nightmare herself?
Princess Luna had gotten her answer. Deep in her subconscious mind, the great land of Equestria had been anything but. Something had seen... off about it. The sky was darkened to as dark a blue as it could be. Dark clouds filled the sky, floating about without a care in the world. The land seemed to have a negative aura filling the air everywhere, as anypony who stepped outside felt a great deal of it, and rushed back inside.
Even the great capital, Canterlot, seemed less lively than it had been. Usually, ponies were abound, tending to their daily pursuits. Now, out in the streets, the same dark aura prevented any of them from departing their homes. The residents there had been through bad times before, but not as bad as this.
In the castle of Canterlot, Princess Luna lay on her underside. However, she did not feel the soft, comforting feeling of her bed. It was a feeling of the smooth porcelain flooring. After a slight moaning, she opened her eyes, and everything seemed blurry to her. Rubbing them made her vision more clear as she looked around.
She was in the Throne Room.
She had been confused for a brief moment, and stood up, rubbing her head as if a pain had been felt there.
"So, you have awakened."
As soon as she heard those words, Princess Luna's eyes shot wide open, and she looked up. She trembled as she saw what appeared to be the horrible image that had assaulted her mind moments earlier.
Staring down at the Princess of the Night was her dark reflection. There was no mistaking those features. A tall black figure with long, sharp wings, a light blue gorget with a helmet of matching color, and an oddly flowing mane and tail that ignored gravity completely. Her eyes were reptile-like, and her cutie mark was just like Luna's, but the more detailed parts were purple instead of black.
Luna had been staring into the eyes of a true nightmare, the image she had once been. Nightmare Moon.
"I had expected you to be unconscious for longer than that. Perhaps I did not use as much of the extent of my power as I intended to use." There was no mistaking that voice, either. It had felt threatening to anyone that stood under it. Even Celestia would be trembling.
"Why are you here? Why are you haunting me... Nightmare Moon?" The last two words, Luna spoke with anger in her voice.
"Haunting you? Poor, poor Luna... you are dead wrong. You do not see the true light... or darkness, as it were... of things. You are of night. It is not wrong to embrace your gift. Why you do not use the full extent of your power, I will not understand."
Luna stood tall and mighty, attempting to stand up to her. Nightmare Moon only raised an eyebrow at this, and continued.
"Do not put on an act of bravery, Luna. Your mind is too small and feeble, and your power is nothing compared to mine!"
A bright flash filled the room as a loud, booming thunder sound was heard, echoing through the large room. Luna winced at this, and lowered herself down, trembling herself, which only drove Nightmare Moon to laugh at her mockingly.
"Do you see? You are too weak. That is why I took over when you were too scared to stand up to our sister. You may not have lowered the moon, but you were thinking about it. No, you needed to show her who should be the one to be scared of, and that is exactly what I did. Who says that just because she is older, she is more powerful?"
"...No. There was a reason for my backing away. I should not have acted upon jealousy. I have paid dearly for my actions, and I have forgiven Celestia for her action. Not that this is anything you'd understand." Luna stood tall once more, and stuck her tongue out.
"What a pathetic sentiment. I understand completely. However, you will always be weak. You may be an all-powerful alicorn, but if you can't suck up all those feeling within you and shrug them off, then you are more pathetic than you look. You don't deserve the title of Princess of Equestria." Nightmare Moon spat. As her horn glowed, the small black crown perched just behind Luna's horn glowed a similar hue, removing itself from her head.
Luna gasped, and her own horn glowed, wrapping its magic around the crown. Unfortunately for her, Nightmare Moon's magic was much more powerful compared to hers, so her grip on the royal object was lost.
Luna took a brief moment to catch her breath before staring angrily at her alter ego. "Hey, give that back!" She yelled as she rushed forward, her horn glowed more fiercely.
Just then, a bolt of lightning struck down onto her back, and she collapsed onto the hard, porcelain floor, groaning in pain. Nightmare Moon only shook her head in disbelief.
"It is no use. You will not have what you do not deserve."
Luna began to clench her teeth tightly, the harsh pain in her back preventing her from standing. Tears started to form in her light blue eyes as she looked up. "That... is mine. You cannot just take from me what is mine."
"Just look at you. You're a spitting image of Celestia. Weak and fragile. She took the pain just as well as you did." An evil grin formed on her dark face. One that was intimidating enough to frighten even a certain fearless speedster pegasus.
"C-Celestia? What are you talking about? What did you do to her?!"
"Do you really want to know? You won't like what you see..." As Nightmare Moon said this, she slowly levitated in front of her and Luna a familiar-looking crown. This one was of a much bigger size than Luna's, and it was of a golden yellow color.
Seeing this made the younger sister more anxious and apprehensive. She loved Celestia more than anypony in Equestria. All the times they both talked together, played together, and even laughed together... Luna loved every single moment.
But she could tell something extremely wrong happened to her, and it was all Nightmare Moon's doing.
"...Show me my sister."
"Our sister. Do not forget, I am a part of you. That makes her my sister as well. Not that it matters to me, of course. She disgusts me. So I had to get rid of her, in one way or another."
Luna gasped. The pain in her back still hurt much, but she was able to slowly stand on her hooves, despite how much pain she felt when she moved even a muscle. "Show her to me... NOW!"
"Very well. Be prepared, because once you see her, the image won't leave your mind."
Her loud voice echoed with a diabolically evil laugh as her mane and tail expanded and swerved around herself. It looked almost like a blue twister. In an instant, she disappeared, and left in her wake, another pony lay.
This one appeared to be another alicorn the same size as Nightmare Moon. However, this one was white, and bore the cutie mark of a radiant sun. She wore a necklace much like Luna, but it was yellow, and looked much more like a necklace than Luna's. Her sandals were just as yellow. She had a beautifully-flowing mane and tail. However, they did not move. Four shades of gray were seen, so to call it beautiful would have been an understatement.
What Luna saw... was her older sister, Princess Celestia, but in a way that seemed like she looked horribly sick, or injured, or even worse.
The younger Princess struggled to step closer to her sister. Against her physical pain, she managed to step over to Celestia's side. There she lay, a limp body resting in front of Luna. At first, she presumed Celestia was merely sleeping. However, the image laying before her still hurt in her young heart.
She mumbled something to herself as she went around the sun goddess' body, stepping closer to her face. What she wanted to know first was if she was properly breathing. The shock from the earlier lightning bolt left her vision blurry, so she could not easily tell just by looking.
She lowered her head near her sister's. A moment passes, but Luna heard nothing. She turns her head so one of her ears hovered directly above Celestia's snout. Another moment passes, but still nothing. She may have been unconscious.
The same dreadful aura from before filled the room as Luna stared worriedly at her sister. Even though the back pain was killing her, it had not hurt nearly as much as what she had felt seeing Celestia in a heap.
The moon goddess moved around her body once more until she stopped in front of her sister's torso. Limping down next to her, she carefully laid her head on the white alicorn's chest, nuzzling against it much like a foal would to its mother. In a way, Celestia was, to Luna, like a second mother.
However, she noticed something as she was doing so. She heard nothing at all. She blinks her eyes, and shifts her head over the spot where Celestia's heart would be. What she wanted to hear was the thumping sound of a heart.
But, she heard nothing. Nothing at all. Luna didn't want to face what she thought could be a reality. But there was no other way to put what she saw before her.
"Tia... please, speak to me... y-you can't be..." Tears filled the light blue eyes of the Moon Princess.
"...Dead?" A sudden voice asked. Luna's eyes widened in surprised as she turned her head to the source of the voice. Once again, Nightmare Moon stood.
"Believe what you see. Your sister, our sister... is dead."
Luna's pupils shrunk, and her heart sunk. This could not be true, she thought. She couldn't be dead, she thought. But she had to face facts; the one and only pony in Equestria she loved and cared about... is dead.
Tears streamed down her purple cheeks. Her face turned from an expression of sorrow to one of anger, which she directed at Nightmare Moon. She quickly got up and turned to the black alicorn, charging once again at her.
"You're kidding. You're kidding, right?" Nightmare scoffed.
Luna reached her, and beat her hooves onto her evil side's chest. Nightmare Moon rolled her eyes in rebuttal, feeling nothing at all. Suddenly, she disappeared, and Luna fell to the floor. The next thing she knew, she felt a strong physical force strike her in the side, causing her to slide along the Throne Room floor into a wall. She yelped in pain as the wall came into contact with her back, which had already suffered from the earlier shock.
Her eyes closed tightly as she clenched her teeth, wincing. A few seconds later, she opens them to find Nightmare Moon standing over her, giving her an intense glare. This created a deep fear in Luna that she never felt before.
"You look just like our dear older sister before her... passing. Full of fear and hopelessness. I'm sure you miss her, don't you? You'd like to join her, wouldn't you?"
As she said this, she lifted a hoof, and positioned it directly over Luna's head. The dark alicorn narrowed her eyes as she stared at the pitiful Princess below her.
"Goodbye, Princess Luna..."
In one swift movement, her hoof swung down, and Luna blacked out.
In the realty of things, Luna seemed to then not be in the Throne Room, but her own chambers. Not lying on the polished porcelain floor, but on her soft, comfy bed.
The Night Princess shook, mumbling words over and over as if feeling distressed in a way. She then suddenly rose up quickly with wide-open eyes.
"NO!"
Luna took heavy breaths. Her delicate face was covered in sweat. Her mane looked somewhat ruffled. A hoof was placed over the location of her heart as it beat rapidly.
She looked up, and noticed three ponies staring at her with concerned expressions: two of them were Royal Guards, and the other, her elder sister, Princess Celestia.
But she didn't look the same as how Luna saw her recently. Her quadruple-colored ethereal mane didn't appear gray, and it flowed as freely as ever. The yellow crown marking her position as Princess of Equestria beautifully adorned her head.
But one important detail overlooked all of those variables: she was alive.
"T-Tia...?"
"Yes Luna, it's me. What has been bothering you? Did you have a nightmare of some sort?" Celestia gave her younger sister the most sincere smile she could give. She had always acted not only as Luna's sister, but as her guardian as well before her banishment.
But this made the younger sister wonder. Was this all just a nightmare? To what it seemed like to her, it had been. Every horrible, frightening thing she witnessed had only been nothing but a bad dream. A true nightmare, even if it seemed real.
That did not matter anymore. All that did matter was that none of it was true, and now Luna woke up to reality. With no hesitation at all, she hopped out of her covers, leaping at the white alicorn. Her wings were extended to allow her extra momentum.
She embraced her sister in a hug, to which said sister first blinked her eyes at, then smiled and wrapped a hoof around the younger pony.
The guards decided to leave the royal pony sisters to their personal moment. As they left Luna's chambers, for a brief moment, miniscule smiles formed on their faces.
"Oh Tia, it was horrible! Equestria was all dark and ominous, and that evil entity caused it all!"
"Discord?"
"N-No. It was..."
"...Nightmare Moon."
She looked up at Celestia as small tears stained her cheeks. The only thing she thought to do was nod.
"I think I understand what's happening. Twilight Sparkle and her friends may have released you from Nightmare Moon's grasp with the power of the Elements of Harmony, but the memories of your past misdeeds reformed itself as a nightmare in your subconscious mind when you slept. You have only returned to us yesterday, so something like that can happen instantaneously. All you need to do is overcome your fears. Stand up to the nightmare within you. Your inner strength shall be the one thing to keep you safe, and you have much of it.
"I know this from the time we, as sisters and protectors of Equestria, stopped Discord's chaotic reign, and brought peace and harmony to Equestria. This inner strength has always been in you. All you need is to let it out, and there would be nothing to fear."
Celestia's speech hit Luna like a rock. She thought back to when they both defeated Discord, and a realization came to her. She was right.
"You're... you're right. I won't let that beast enshroud my better judgement. Thank you."
"Anything for my little sister."
"Oh, and one more thing..." Once again, the Moon Princess embraced the Sun Princess.
"I love you, Celestia."
"I love you too, Luna."