“Well, this is an unexpected development.”
Nightmare Moon looked around her room, expecting to find her sister looking down on her with a smug grin, but it seemed she was alone. The lights were off, the room was tidy, and the door was shut. There was no indication that anypony had even entered the room while she was distracted. It was as though a heavy iron cage had simply materialized around her bed.
Somehow, the cage looked familiar, but she couldn’t quite place where she had seen something similar.
Slowly, calmly, she got up from the bed. It was a massive cage, such that even with the bed she had ample space to walk around. The bars were thick, old metal, and when she pressed against them with a hoof they gave no signs of weakness. Nor could she move vertically; the floor and ceiling of the cage were made of the same material.
She contemplated the bars for a moment, considering playing along, but quickly decided against it. No, she had no intention of ceding any ground to her sister.
She stepped back from the bars and lowered her head. Digging deep inside, she tugged at the well of anger inside of her, and focused all that energy into her horn. She braced herself, grimaced, and let loose.
Nothing happened.
Not even a spark of magic flew from her horn. She tried again, and again she failed. She wasn’t able to conjure up even the hint of a glow. She could find no light, no energy, no fire. Her magic had been completely cut off.
She bared her teeth and narrowed her eyes in rage. This was over the line, and she was quickly growing weary of playing along.
“Sister!” Her booming voice echoed through the entire castle. Birds flew from the ramparts, and in nearby houses ponies rose from their slumbers. Even the bars of the cage vibrated long after the noise had stopped.
Celestia didn’t waste time. Immediately the door swung open, and the lights flicked on as she entered the room. She had a solemn frown on her face, but at seeing Nightmare Moon the expression flickered with disgust.
“Release me,” Nightmare Moon demanded.
“Oh, I shall,” Celestia said, “once you release my sister.”
“I. Am. Your. Sister!” Nightmare Moon slammed a hoof against the bars with the final word.
“You’re a parasite! You may have fooled all the others, but I am the pony who faced you a thousand years ago. I know what you really are.”
Nightmare Moon scoffed. “Of course. Arrogant as always! Not a single pony in Equestria believes you to be in the right, and yet you ignore them.”
“It’s my job to protect Equestria, no matter the cost.” Celestia marched forward and came face to face with Nightmare Moon. “If sacrificing my reputation is what it takes, then that’s what I’ll do.”
“So what? You lock me in a box until I play nice?”
“Oh, that’s far more than a box,” Celestia said. “We went through a lot of trouble for this prison.”
“We?”
“Why don’t you come say hello?” Celestia said to somepony in the other room. “Let her know just how beloved she really is.”
There was a long, agonizing pause. Nothing happened, and neither of them spoke as they stared at the doorway.
Then, with a deep sigh, Star Swirl walked into the room. “I’m sorry for this, Luna,” he said.
Nightmare Moon took a step back in shock. For a second, she had no response at all. Then, her face broke into a grin. “Hah! Why are you sorry? This is a dream come true for you!”
“Do you think I enjoyed taking a trip to Tartarus with the intention of locking up one of my students?”
“Did you not?” Nightmare Moon walked to the corner of the cage, where she was closest to him. “You know, Star Swirl, with how hurt I was to find out you saw me as a monster, I would have expected this to sting more. Perhaps I have truly accepted that I will never be trusted.”
“I did trust you, Luna,” Star Swirl said. “I trusted you not to do this.”
“To do what? What have I done?” Nightmare Moon took a step back and gestured around herself. “To not rule in my sister’s stead? To not look to better my standing in the eyes of my subjects? To not do the one thing she’s meant to do, the thing I was banished for, and lower the sun when she would not? For which of these crimes am I being condemned?”
Star Swirl turned away and closed his eyes, unable to answer.
“Enough of this,” Celestia ordered. “Nightmare Moon, this is your final chance. Relinquish your hold over my sister, or return to the moon.”
“As I have repeatedly said,” Nightmare Moon responded, “I am your—”
Before she could finish the sentence, Celestia fired a blast of magic at Nightmare Moon, and just like that the cage was empty.
Star Swirl sighed and shook his head. “This is not how things should have gone.” Slowly, he approached the cage and placed his hoof on a bar. He closed his eyes, concentrated, and with a puff of smoke the cage disappeared, sent back to Tartarus.
“She never should have returned,” Celestia said.
“I suppose not,” Star Swirl admitted. “Tomorrow, I shall go to the moon and speak to her. Perhaps I can dissuade her from this foolish path. Now, though, I need my rest.”
Star Swirl started walking for the door, but just as he reached it a wall of icy blue flames erupted in front of him, trapping both him and Celestia in the room.
“What?” Star Swirl jumped away from the fire in shock.
Celestia’s cheeks flushed red with anger. “Impossible!”
In the middle of the room, right where the cage had been, a massive pillar of smoke and flames erupted from the ground. It swirled viciously, strong enough to engulf the entire room.
Then, the flames vanished, and left standing in the wisps of smoke was a very angry Nightmare Moon.
She took a step forward, and that hoof erupted into flames. “Did you think my first return was a fluke?”
She took another step, and another hoof combusted. “Perhaps you thought me weakened?”
Another step, and the remaining hooves lit up. “Or did you just believe you were that strong?”
Star Swirl acted quickly, firing a beam of light at Nightmare Moon, but she batted it away with a hoof, not bothering to even look in his direction.
Celestia was standing tall and proud, defiant against the incursion as Nightmare Moon continued her advance.
“I have been merciful, dear sister.” Nightmare Moon swiped a hoof through the air, and rings of fire erupted around Celestia’s legs. Wicked tendrils lashed out from them and chained her to the floor.
Celestia stayed silent, her head held high.
“I’m only going to do as you did to me.” With another swipe, flames looped around Celestia’s horn and tightened down on it. Pulsing veins of fire crept their way into the horn, cutting off her magic from the inside.
Just before her magic left her completely, Celestia lit up her horn one last time and vanished from the room.
With another swipe of her hoof, Nightmare Moon sprouted a spire of flames from the floor, and when they dissipated Celestia was back.
“Were I as cruel as you believe, I’d simply break your horn off and be done with it.” Nightmare Moon took the final steps, and was nose to nose with her sister.
Celestia snarled. “You’re only proving me right.”
“Am I?” Nightmare Moon grinned wickedly.
Then, very slowly, she closed her eyes and took a deep breath. In, and out, and in, and out, focusing on her rage and letting it flow away. She felt the adrenaline release the stranglehold on her mind, and as it did she changed, shrinking from the imposing form of Nightmare Moon into the kind, docile Princess Luna.
“What?” Celestia muttered.
Luna opened her eyes, and they burned with more intensity than ever before. “Don’t worry,” she said, “a thousand years isn’t that much longer than it sounds. Do tell me how the sun was when you return, won’t you, dear sister?”
Then, before anything else could happen, Princess Luna focused her magic and fired it at her sister, banishing her to the sun.
Star Swirl staggered back away from her. “Luna, how could you…”
Luna took another deep breath, and when she let it out she let her anger go and gave way to Nightmare Moon again. “It’s no worse than she’s done to me,” she said calmly.
“Blind revenge is not the way to move forward!”
Nightmare Moon glared at him. “I tried talking. I gave her every chance to be reasonable, far more than she deserved, and every time she spat in my face. Why are you not lecturing her about the value of rational discussion?”
“I was not silent on our journey to Tartarus,” Star Swirl told her. “You are both out of your minds, but I believed I could actually reach you! I thought I could make you see that giving up this stubborn ‘Nightmare Moon’ act is the only way she will listen to you.”
“I’m finished making sacrifices to appease my sister. Now, if you will excuse me, I have a sun to raise.” Nightmare Moon moved past Star Swirl and left without giving him a chance to respond.
In another world, chained down amidst endless fields of fire, Princess Celestia screamed in rage and despair.