"Luna, what are you writing?"
"Private correspondence"
"To whom, might I enquire?"
"An old friend who lives far away now."
"Oh, well, carry on."
"Can we talk?"
"About what?"
"About you."
"Why is it always about me, huh? It's never you, it's always me who needs talking to!"
"Luna, I—"
"''m sorry'? No you aren't! You're never sorry! You do not feel sorry for me. You feel sorry that I do not mold to the shape you want. You're sorry that things aren't fitting your clockwork form. I'm not your minion! I'm a princess, your equal! Sometimes I feel like your superior!
"Luna, there are traditions for a reason! You can't just go around changing how things work. I have offered you a myriad of ideas for how we can constructively address this problem, but frankly, I don't think you want to listen."
"I don't want to listen? I don't want to listen? You throw little trinkets of remedies at me! They don't work! Nopony comes to my night education classes! Nopony cares about daylight savings. They just sleep in longer! Nopony cares that I've added twelve new constellations this month. The only ones who notice are drunk revelers stumbling home. You know how many copies of Starswirl's Guide to the Stars, 12th Edition have been taken since we made it free? I checked. Fifty-six. Fifty-six! These are not panaceas. These are crummy band-aids. You know what I want: More night!"
"Luna, what is happening to you? You won't even talk to me anymore. It's like you're not even yourself. Where's the little sister I used to know? I want her back. Come back please."
"I'm not your shadow, Tia. I'm my own mare. I can make my own decisions. I can be my own pony. And you can't stop me."
"I don't want to stop you! I just want to understand! What's happening to you? Why won't you let me in?!"
"I have others, you know. I don't need to rely on your company. Unlike you, I have friends. Friends who care about me, who love me for who I am, not who they want me to be."
"You're lying to yourself, Luna!"
"Like you aren't?"
"Did you really expect me to sit idly by while they all basked in your precious light?
There can only be one princess in Equestria! And that princess will be me!"
"Luna, I will not fight you! You must lower the moon! It is your duty!"
"Luna? I am... Nightmare Moon! I have but one royal duty now: to destroy you!"
"Oh, dear sister. I am sorry, but you have given me no choice but to use these."
Celestia held the tear-stained letter in her hooves. The ink had bled to the point of being unreadable, but she had long ago memorized the words. She looked up at the sky, staring longingly at the moon—her moon. This was no different than any other night, save one thing, the one thing that gave her any sort of hope. That number she hated and loathed herself for—172,231 days—was now just a little smaller.