Luna blinked open her eyes to find herself in a ethereal space full of stars and nebula. Princess Celestia stood a few feet away from her, her eyes dark.
"Where have you brought me? Why can I not use my magic?" She demanded.
"This is my dream world. I control this world, so I decide who can use their magic," Luna said calmly.
"So you bought me here so I could be defenseless?" Princess Celestia snapped.
"I have no desire to duel you," Luna replied. "But," Luna took a step towards her sister. "I plan to restore you back to your original state. I only wish for you to become my sister once more."
"I am your sister," Celestia insisted.
"Really? And what kind of sister would say such words as the ones you said outside in Ponyville. You are a monster inside my sister's body, poisoning her mind," Luna took out the broken pieces of her necklace.
"What are y-" Celestia began, but Luna cut her off.
"This necklace was made on my birthday last year. It was a very special necklace. Both of us made it together... we put all of love into it. Love for each other," Her eyes grew solemn.
"What are you trying to do?" Celestia said boredly. Luna glanced back at her and uncovered two books that hovered next to her. One had the same design as the necklace. The other had the picture of two alicorns on it.
"Open it," Luna said calmly, hovering the book in front of Celestia. The white alicorn looked puzzled but opened it. As she did, pictures flowed out from the book and enlarged into the space next to them. Luna trotted among the path of stars laid out in front of her, turning her head to look at each photo. Without speaking, Celestia unexpectedly followed her, eyes glittering with emotion as she looked at the memories of Luna and herself.
" Our sisterly bond can not be overcome by the greediness for power. You know that as well as I do," Luna said quietly.
"But Asteria, she is our sister as well," Celestia said uncertainly. Luna blinked slowly.
"She can not rule beside us. She disrupted the harmony between us and the peace in Equestria. We bring harmony by bringing the day and the night. And what has she done?"Luna inquired. "Kidnapped you, used you as a pawn to try and defeat me, poisoned your minds with lies against me," She continued.
"Those words you said out there were not of one who is a ruler. The amulet may give you more power, but that power has replaced the love and trust of your subjects....and me," She whispered. She held her head high and looked into her sister's eyes. "You have forgotten the most important magic of all. You taught this to Twilight Sparkle for many moons. She and her friends have magic more powerful than the magic the amulet possesses. The magic of friendship." Luna spread out her wings widely as she spoke those last words. At that,Celestia turned to face her, the red gleam in her eyes fading and returning to its regular magenta color.
"Luna, I'm sorry," She whispered. She walks forward and wraps her wings around her sisters for the first time in days. As she did so, the amulet popped off and disappeared through the ground. The broken pieces of the necklace swirled swiftly. As the sisters' feeling of love for each other spread, a small wisp of magic, one yellow, one blue, drifted into the air and into the pieces of the necklace. They came back together and the necklace was restored, glowing brighter than ever. The space of stars and nebular faded away and Ponyville shifted into sight.
Then suddenly, without warning, Luna felt a sharp pain at her horn. The space where they were standing began to crumble and a small portal appeared at the end of the starry hallway. Luna strained at her magic to keep it together.
"Luna, what's wrong?" Celestia asked in a panicked voice.
"I-I used too much magic to summon this place, and now its crumbling. Go while my magic keeps it together!" Luna cried, her horn glowing brightly.
"Luna, you s-summoned this star world? How could you use so much of your magic just to create it and bring us here?" Celestia cried out over the rumbles.
"There was no other way. Go NOW! I'll find a way out, I promise!" Luna pleaded.
"I can't! I won't leave you alone again. Luna..." Tears began running out Celestia's cheeks. Tears of her own ran down Luna's. She already knew the price of doing this. Nevertheless, a rule must make sacrifices when necessary.
"GO! Please! They need you!" Luna shouted. Celestia backed away, her eyes filled with anguish and disappeared through the already shrunken portal. Luna sighed softly as it closed up completely.