Nightmare Moon slammed her hooves down on the surface of the moon, throwing up clouds of dust. She unfurled her wings and gave them a few flaps in irritation, but with the lack of air, and thus wind, the dust just hovered there before slowly falling back to the ground. Her horn sparked in anger, throwing dark blue sparks into the empty sky. She growled. “Why didn't it work!?” she shouted to the empty sky, while another Alicorn mare stood close by and looked on, “we had it all planned out! Our army would take Canterlot and then we would force our sister to accept the night, along with all of her sunloving subjects! Why!?” She slammed her hooves down again, sending cracks along the rocks around her.
“We went too far.” Nightmare Moon turned to look at the Alicorn, standing there dressed in her silver regalia. Her midnight blue mane flowing ethereal and reflecting the shimmering stars that shone down on the two mares. The mare turned to stare at the blue, white, and green sphere to their side, gazing down at the world and wondering how her sister was dealing with her absence.
“We didn't go too far!” Nightmare shouted at the mare, “you had to get cold hooves at the last moment! If we hadn't sent away our battalion when we stormed the castle, we would have what we wanted!”
“And then what, Nighty? What would we have done after that? Our goals were short sighted when you think about it.”
“Don't call us that,” Nightmare growled. She hated the nickname that silly mare had given her, the one that the Element of Laughter had chosen to bond with.
Princess Luna shrugged. “You better get used to it,” she said, “as long as we're here, I'm the only company you'll have.”
“Not if we can help it,” muttered Nightmare, making Luna smile.
“I wouldn't count on it, we may be on the moon, but our magic is limited without the flow of the Leylines of Equestria,” she smirked, “besides, we have some work to do.”
“What are you talking about? We are doing work! Plotting the downfall of Celestia!” Nightmare snapped.
“It's not that,” Luna stated, “you didn't feel it because you haven't wielded the Elements of Harmony before, but when Tia used them on us, I felt a great loss. It was like Harmony was failing.”
“That makes sense,” Nightmare sneered, plopping down on the moondust filled ground, “she can't really wield all of them, now can she? Only our parents could. That does mean that it's only a matter of time before the seal that's upon us fails, meaning we will then be able to return to Equestria and take what we want!” She clapped her hooves together, a smile on her face.
Luna just shook her head before hearing a pop of teleportation. She glanced around, spying a bit of color in the stark gray of her moon. She walked over to it and smiled as she saw that it was a small, stuffed replica of her sister, complete with the sun cutie mark on her flank. She squeed as she picked it up and squeezed it tight. As she sat there, memories flowed back to her.
The first time she'd gotten Tiny Tia, as she called the doll, was when she was only a filly. Celestia had spent months working on it, making sure that it was perfect, pouring her love and thanks into the doll. She'd spent the entire day gliding around the castle and grounds, playing with the doll and showing it to all the guards.
Then she saw herself, older, holding the doll as tears ran down her cheeks and onto the ground. It was shortly after their parents had died, leaving Tia and herself to rule the entire country. She'd just come back from the funeral, they'd died fighting off an army by themselves as they gave their subjects time to retreat into the fortified walls of Canterlot.
The next memory was after a long day dealing with the nobles. She sat on her bed, now almost fully grown, and clutched the doll in her hooves. She whispered all the problems she'd had that day to the doll, knowing that it couldn't hear her, but glad that somepony would listen.
She smiled as she looked down at the doll, sitting on the moon and remembering many of the sweet memories she carried with her.
Nightmare Moon watched this foolish and foalish display before jumping as she heard a pop close by. She looked to one side to see a large staff embedded into the ground. She wrapped her magic around it and yanked it from the ground, throwing up another cloud of dust. She swung it through the air and smiled as she recognized the crescent moon that sat at the top of it. She stood up and planted the butt of the staff on the ground, the head of it extending above her horn. She felt a shiver of power flow down her spine and she grinned.
She felt familiar memories wash over her like a warm shower, compared to the freezing cold of the moon.
She stood in the front of her armies, glaring down at the futile efforts of Celestia's army to stop their approach to the city of Canterlot, the gleaming white city built into the side of a mountain. She turned back to view her armies, pride radiating from her at the strength and power they wielded. Even the griffins had been hard pressed to stop her advancements into their lands. Eventually they had fallen, yielding under her might.
The next one came with a ungoddess like squee of glee. It was seeing Celestia collapsed on the floor, wounds bleeding and body bruised from their long fight. She had tried to stop Nightmare, but nothing had come of it except pain and death.
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
“Why couldn't you understand what we were going through!?” she shouted at the fallen Alicorn, “you, with your precious sun and adoring subjects, would never understand what we felt!” She kicked her in the ribs, hearing and smiling at the satisfying sound of one of them snapping.
Celestia gasped in pain before responding, “I didn't think it had gone this far,” she coughed, blood splattering the stone floor.
“You didn't think!?” Nightmare leaned down and yelled in her ear, “you didn't think of anything else except your throne! You didn't think about the only family you had left! You didn't think about what we were feeling! How helpless we were, trying to accept our subjects' decision to play during your day and sleep through our night! YOU DIDN'T THINK!” She slammed her hoof into Celestia's ribs again and again as she screamed out in pain. Nightmare Moon grabbed Celestia's throat in her hooves and threw her against the wall, slamming her head against the cracked bottom of a pillar.
Nightmare felt something cold run down her cheek and fall onto her hooves. “You didn't think about your sister,” she sniffed, pressing her hooves into Celestia's neck and cutting off her air, “you didn't think that we were her only friend. You didn't think to take care of your sister after your parents died. She was hurting, screaming for attention! And you ignored her, you just ignored her.” She let go of the wounded Alicorn and slid down onto the floor, tears running down her face and splashing on the ground around her hooves. “You never think about anything else except your fame,” she whispered, “even when our parents were alive, you just focused on being loved. You never thought about loving. Luna called out for you every day, hoping you'd hear. But you never did. You never heard her.”
She felt the warm embrace of Celestia as she was wrapped in her hooves, pulled close to the warmer than normal body. She shivered, sobbing into Celestia's coat.
“I'm sorry,” Celestia whispered, “I never meant for this to happen. But I have to do something.”
“It's useless,” Nightmare said, sniffling, “you can't fix the past.”
“Yes,” Celestia agreed, “but I can change the future. Perhaps I can save you from yourself, Luna. Then I can prepare for your return.”
“My return?” Nightmare's eyes flashed from the turquoise slits to the blue of Luna, then back.
“Yes,” Celestia now looked down at her with sorrow, “I'm sorry I have to do this, but the Elements won't choose new bearers until we break our hold on them. This is the only way I know how.” She pulled back, leaving Nightmare to sprawl out on the floor. Nightmare stared, horrified, as Celestia called upon the six Elements of Harmony. The six gems rotated around her, glowing softly.
“No,” Nightmare pleaded, “please, no. I don't want to be alone again!”
“I'm sorry, Luna,” Celestia cried. Her horn glowed with the light of the sun, then channeled it into the six gems. They grew brighter as Nightmare crept forward, tears streaming down her face.
“Please, there must be another way!” Nightmare begged.
“I've looked into it, there isn't.”
“Please! Stop!”
“Goodbye, Luna.” Tears ran down Celestia's cheeks as she charged the Elements, then they erupted in a rainbow of colors, slamming into Nightmare and blasting her to the silvery moon that sat in the sky, leaving a trail of rainbows behind her. Nightmare could only scream in anger and sorrow as she was banished to the moon.
As the rainbow faded, the Elements dimmed and turned gray, finally transforming into spheres of cold stone and clattering to the ground around the sobbing Alicorn of the Sun.
“Please forgive me, Luna,” sobbed Celestia, “I never meant for this to happen.”
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
“Nightmare?”
Nightmare Moon snapped back to reality, only to see Luna staring at her, their faces only a few hooves away from each other.
“What?” The question was meant to be biting, but it came out as more of a sob.
Princess Luna wrapped the night mare in her hooves and pulled her close as she let tears drip from her eyes. “I know how it felt,” she whispered, “I know how it feels to be betrayed. I felt that way every day. Every time I saw Tia, I hoped she'd pay attention to me as a sister instead of a co-ruler.”
They sat there for a long time as Nightmare poured out her anger, then her betrayal, then her sorrow onto the coat of the smaller Alicorn. Finally the tears seemed to stop, though she knew that there would be many more, and Nightmare pulled back. They stared into each other's eyes, coming to an agreement.
“If Tia is working on reestablishing the connections of the Elements of Harmony to ponies,” Luna began.
“Then it's up to us to create trials for them to strengthen that connection,” finished Nightmare. They both grinned and Nightmare wiped away her tears, flicking the small orbs of liquid away and off into the emptiness of space.
Nightmare reached over and grasped her staff while Luna held onto Tiny Tia. They grinned at each other, then Nightmare began dragging the staff along the ground, drawing out a map of Equestria. As she did, Luna would mark places of interest, as well as possible trial locations. When their seal broke, they would be ready. Not to take back Equestria, but to help protect it.