Everything was a white room. Circular, with a domed roof. There was nothing else, no door, no windows, no furniture. Just the white walls. The white walls that pulsed in time with Luna’s heartbeat. Occasionally, there would be sparks of color, flashes of red and orange, blue and black. But there was no noise, other than the blood rushing through Luna’s body and her heart beating, so loud in the ensuing silence. She paced along the edges of the room and attempted spell after spell to no avail. Some force was blocking her magic. Even her wings refused to give her lift. She lay dejected on the ground and put her head in her hooves. She had been trapped in this white prison ever since she gave the Nightmare in her mind an opening to her body. The beast had promised her everything she had ever wanted, power, glory, and adoration. The adoration of all the sun-loving ponies who played in sister’s day and slept through her star-kissed night.
“AHHH!” A scream ripped through Luna’s throat and vibrated with a navy hue in the surrounding air as Luna crashed into the far wall and lay there gasping for air.
The white room continued to rock back and forth as another voice screamed in agony. Then, the white room seemed to be flung at an incredible speed. Luna felt as though she would puke. As soon as it started, the earthquake stopped and Luna’s momentum carried her into the opposing wall with a similar crash. Bleary eyed, Luna looked around the room and saw, something. It was color, but it wasn't flashing back and forth across the room’s walls like lightning. It was steady, and the only color it showed, was a blue so dark, she thought it was black.
“I am so sorry, Luna. Please forgive me.” A voice echoed into the gap and reverberated around the room with pale yellow sparks flashing out from it.
“Foolish mare, you should have known better than to make me angry. When I get back to Equestria, nopony shall be left standing. They will all bow to my night!” This voice was less familiar, it left a trail of black as it streaked across the white walls with murderous intent. Luna shrank back from the malevolent words and pressed herself against the living walls.
“Hello, is anypony there? Tia? Big sister, I’m sorry!” Luna’s words manifested with a navy blue gleam and raced out of the room, echoing in the space beyond the minute gap.
“What in the-!” The voice of the Nightmare returned and reverberated throughout the walls, shaking Luna as she collapsed unstably on the white floor. Black daggers raced through the room and buried themselves in the walls. The room shook and then collapsed inward slightly until billowing out and stopping all movement whatsoever. A large black mist streaked into the room and floated in front of Luna. Suddenly, black legs stretched out from the mist and landed on the ground. Wings sprouted from the middle of the mist and flapped once. Beams of cyan light slashed through the mist and coalesced into eyes with narrow slits for pupils. The remainder of the mist condensed into a mane and tail, and a large, black, equine body emerged.
Luna stared in disbelief at the Nightmare come to life. The black equine stared back, not daring to believe that the insignificant filly she had imprisoned, had managed to crack the shell of the white prison.
“Who are you, Demon?” Luna took an offensive stance and lowered her horn, all the while glaring at the Nightmare.
The Nightmare circled Luna, Luna turned to face her every time. “I don’t really have a name. You didn't exactly give me one, but you can call me… Nightmare Moon.” The ebeneous mare stood tall, her evanescent mane reaching forwards and stroking along the side of Luna’s neck, causing her to shiver and flinch backwards.
“What happened? Where am I?” Luna was shaking now, shaking with a strange mixture of fear and anger. Anger at Nightmare Moon, and anger with herself for not knowing what was going on.
“Why, we just switched places. Don’t you remember, dear Luna? You agreed to let me take control, as long as you got everything you wanted. Power, the crown, and adoration of the foolish ponies that dare to sleep through our beautiful night!” Nightmare Moon’s mane whipped throughout the room with a fury, sending lightning bolts arcing through the room and scorching the crystalline walls.
“Why are you here then? How did you get into this room? Who’s controlling my body?!?!” Luna was beginning to panic and it was showing clearly on her face.
Nightmare Moon laughed, it was a sound that made Luna want to crawl under a rock and never come out. “Why, our big sister banished us, or maybe me. Our body was infused with the moon and now, I am stuck in the same wretched prison as you are. The same prison I was in before I took control of our body.”
“Celestia, banished us? Why would she do that, Tia’s so annoyingly peaceful it hurts! What did you do to make her banish you?” Luna sat down suddenly, shocked into silence.
“Oh, nothing much. I just tried to take over the world and plunge into eternal darkness so that everypony could see our beautiful night.” Nightmare Moon stared at Luna’s bug eyes and gaping mouth, “I do suppose the stars will align for my escape in about a thousand moons or so,” Nightmare Moon mumbles under her breath some more. She then proceeds to stare at Luna, who remains sitting on the marble floor, unmoving.
Nightmare Moon eventually grows bored and begins to carve something into the air with magic. Luna watches as four lines appear in the air in front of her, two horizontal and two vertical, criss-crossing each other. Nightmare Moon draws an ‘X’ in the middle one with the tip of her horn. Luna, shaken from her dull stupor by Nightmare Moon’s mane consistently poking her, draws an ‘O’ in the top left corner box. They proceed like this for several rounds.
Suddenly the entire room begins to shake. Luna and Nightmare Moon are forced into the ground by the momentum of the room going upwards. The motion stops as suddenly as it started. The two alicorns stare at each other, as if they will find the answer in the other’s eyes.
“What do you think just happened, Nightmare Moon?” Luna is the first to break eye contact with the other.
“I think, our sister is raising the moon,” the Nightmare stares at the minute crack in the wall. “Do you think, we could break out of here through that crack?”
Luna follows Nightmare’s gaze and walks towards the sliver of silver light. “No. Unless it got bigger, I don’t think there is anyway either of us would fit. And the walls are so smooth, they give you no purchase. I think we will have to wait it out.”
“Wait it out, wait what out? We’re not getting out of here unless Tia deems it okay to free us. You do realize that right?” Nightmare Moon merely stares at the terrified Luna, the smaller alicorn horrified by the thought that they might not get out, ever. “You lost to her once, why would you win this time?”
Nightmare Moon’s head whips to stare at Luna, she takes one step forward and is suddenly in front of Luna, her horn point directly at Luna’s heart, oozing a sickly black luminescence. Luna freezes, staring at the black alicorn that could kill her with one step forwards. Luna moves her hind leg backwards and feels the wall behind her. Unable to move, she stares at the Nightmare.
The Nightmare smiles, “Poor, sweet, little Luna. So naive.” Nightmare Moon leans back and cocks her head slightly at Luna, still smiling her sickly sweet grin. “Tia hates you, she kept you in her shadow for all those years. Everypony laughed, and played in her glorious day.” Nightmare Moon’s words wrap around Luna’s head, they worm themselves in and out of Luna’s ears, sinking the Nightmare’s lies deeper and deeper into Luna’s mind. “But what did they do during our beautiful night? They slept, and shunned us. Nopony, not even our so-called loving sister appreciated how hard we worked. Celestia raised the sun, but we raised the moon AND arranged the stars.” Nightmare Moon steps away from Luna, leaving the young alicorn swaying slightly with eyes staring at nothing.
“No, it was never you. YOU never raised the moon, or styled the stars. I did that, it was my jealousy that formed you, wasn't it.” Nightmare Moon whirls around to stare at Luna. Luna stands and glares at Nightmare Moon, her horn beginning to glow a threatening navy. “WASN’T IT!!” Luna’s eyes stare wildly and her horn begins to create sparks that scorch the walls and floor.
Nightmare Moon steps back warily. “Yes, it was. I am nothing more than something you created to destroy your sister.” Luna staggers and lowers her head at the confirmation of her worst fears. “That is what you wanted to hear, isn't it.” Luna’s head snaps up to stare at a grinning Nightmare Moon. “I’m sorry, but that’s not true. I am a demon, come to prey upon your darkest desires and most hidden fears. Or maybe, I am nothing more than a dream.” The Nightmare laughs, chills gallop down Luna’s spine and ka-Thump as they reach her tail and cause it to lash and spark wildly.
Luna’s snarl echoes around the room and all is still as the navy light around her horn concentrates in an ephemeral spark that lances around the room to strike Nightmare Moon in the chest. The room shakes with the weight of the black alicorn as she crashes into the floor with an earth-shattering crash. Luna’s stance relaxes and she turns to stare at the wall as it begins to dance with lights. Stars and constellations begin to fill the room. Luna hears a low, hacking cough behind her and turns apprehensively. She stares at the Nightmare who stands and turns to stare at a glowing rectangle of light behind her.
“It seems as though time moves swiftly here. I’ll be seeing you little Luna.” The Nightmare flicks her midnight tail and gallops towards the light, Luna close behind.
“No, sister. I’m coming, please help me, Tia!” Luna gallops on the wind and stretches her neck to race the Nightmare.
Nightmare Moon smiles as she passes through the light a split second before the little, blue alicorn. Luna screams wordlessly as the light vanishes and she crashes into the wall.
Black daggers arch into the room from the broken wall and carry Nightmare Moon’s words, “Too bad, little Luna. You were so desperate. Oh, well. Say hello to Tia would you?”
“NOO! Leave Tia alone, you demon!” Luna rams herself into the walls over and over again in an attempt to break through into the verdant land of Equestria.
Time passes and Luna collapses on the ground, sobbing and bruised. Still screaming and ranting between heaving, tear-stained breathes, Luna feels her resolve, and her chance of being free slipping farther and farther away.
“I am so, so sorry Tia. I never should have done this. Please, let me come home.” As Luna’s next, broken tear splinters onto the ground, the walls begin to scream and creak with the moans of a million dying animals. Light splinters through the walls and burns Luna.
Screaming a wordless battle cry of agony, Luna staggers to her hooves. Lining herself up, she launches herself at the walls in one, last, desperate attempt to break free. The walls splinter into midnight blue and black shards and she stares up at a glowing white alicorn with a pastel mane and tail.
Luna stands and hugs Celestia, “I’m so sorry, I missed you so much, big sister.”
Celestia stares down at Luna and states simply, “I missed you too, little sister.”
Luna then pulled away to stare at her surroundings and, more importantly, the six mares and one baby dragon staring at her. Five of the mares wore necklaces with large jewels in the shape of the individuals cutie embedded in it. The sixth wore a large tiara with a pink star at the top. Luna looked back at Celestia and rested her head on her big sister’s chest, closing her eyes and letting the pink mare’s words flow over her.
Luna’s ears prick up at something about a party before she sits down and falls asleep, surrounded by the shattered pieces of Nightmare Moon.