One pot amongst the multitude of earthen vessels,
Shall it argue with the potter who fashioneth it?
Shall the clay say unto the potter, “What makest thou?”— Isaiah 45:9
Low on the horizon a portly moon spilled golden light across the mirror-smooth water only to be broken in myriad shimmers by the wake of a silently gliding ship carved from crystal glass. Its sails were midnight blue, and a pony of like color rested upon the noble prow, her silver-clad hooves hanging over the railing. Gazing downward at the stars reflected in the water, she smiled softly. Her reflection smiled back. Her decorative collar was black, emblazoned with a crescent moon that matched the mark upon her hip. A mane of soft, periwinkle blue hair poured out from under her hat, which curiously enough seemed to be improvised from a folded map.
A voice called out from somewhere aft, “What course, Commodore Luna?”
Luna lifted her head and called back over her shoulder, “Second star to the right, Captain Saltheart, and then straight on ’til morning!”
A shadow passed overhead, unnoticed but for the ever-so-soft ruffle of feathers, followed by a clatter of shod hooves upon the deck. Luna whirled about and gasped, wide-eyed, at the dark, armored figure. “No…”
Nightmare Moon furled her wings and stepped forward. “Luna… I’m pleased that you are still alive.”
Luna pushed back against the railing, backed into a corner. “No, this can’t be! You… You’re me. But I’m not like that anymore. This is only a bad dream.”
Nightmare nodded. “Tis a dream, but I bid you not awaken. We need to speak, you and I.” As if to convey that she’d come in peace, Nightmare Moon sat on her haunches upon the deck of the crystal ship.
For some moments the two dark alicorns sized one another up; the waving of Nightmare’s starry mane and tail was the only motion. The moon hung large in the sky, waiting for their next move.
Although Luna’s heart still pounded, a spark of curiosity began to assert itself. She licked her dry lips and then ventured, “I thought the Elements of Harmony destroyed you.”
Nightmare Moon answered softly, “I’m not exactly sure what I am now, but I still have some shadow of existence here in the world of dreams. And what of you?” Before Luna could formulate a response, Nightmare’s horn glowed. Luna flinched, but the aura merely lifted her paper hat and floated it closer to Nightmare Moon, who shook her head sadly. “Is this your new crown? Have those corrupted elements reverted you to fillyhood?”
“It’s not like that! I mean, it’s sort of like that… but Celestia thinks I’ll regain my size and power as I recover.”
Nightmare’s eyes narrowed. “You call her Celestia? You know what that name means.”
“She’s ruled over Equestria — day and night — by herself for a thousand years, so I think she’s earned it. And she hasn’t done such a bad job.”
Nightmare hissed, “She hasn’t…” Then she caught herself, and asked in a calmer tone, “Really? I didn’t get to see much of modern Equestria before being blasted to oblivion.”
“It’s… Nice. I mean, Celestia’s had a millennium to shape Equestria in her own image. You know how she is. It’s all sweetness and light, knowledge and reason.”
Nightmare scowled. “Yes, she was always so devoted to reason. She never appreciated instincts, myths and dreams. And she had no qualms about writing us out of history, except for select bits of slander.”
Luna took a deep breath and said, “Why are you here? Why rehash all of this now? What’s done is done, the world has moved on without you, without us. You should just fade away and leave me in peace.”
Nightmare Moon frowned and looked down at her hooves for a moment. Then she looked to Luna again, her brow furrowed with deep concern. “This is all acceptable to you? Being so diminished in power and stature, becoming Sola’s overlooked shadow once more? Does your heart no longer blaze with the outrage of what she’s done to you? A thousand years…”
“It wasn’t her fault!” Luna had raised her voice and flared her wings. “It was your fault! It was your jealousy and anger and cruelty and madness! You were never going to let the sun shine on Equestria again!”
So startled was Nightmare Moon by the fury in Luna’s accusation, she scooted back a little. Her mouth worked futilely as she tried to find words, then she blurted, “How can you say that? I’m you! You can’t really blame yourself.”
“I can! I’m the one who invented you, I dreamt you up, and you were the worst idea I ever had. I thought you’d bring me respect and admiration, but all I’ve gotten is misery and regrets.”
Nightmare Moon stood up on all fours. “No. I see what’s happened. The Elements of Harmony… They did more than weaken you. They’ve brainwashed you too! They’ve sapped your will, twisted your thoughts.” She began walking closer to Luna.
Luna’s confidence faltered, and she backed into the corner again. “St-stay back!” Then she glanced past the black alicorn and shouted, “CAPTAIN SALTHEART, WE HAVE AN INTRUDER! CALL THE CREW TO REPEL BOARDERS!”
Nightmare Moon snarled, “Captain Saltheart isn’t here. He’s dead! He’s a thousand years gone, just like every other friend and follower you ever had — thanks to your sister! Did you forget that? You don’t even know anypony you can dream about who isn’t lost in the mists of time.”
Luna whimpered and squeezed shut her eyes. But in a moment she felt hooves embracing her muzzle on either side — gently, tenderly. She opened her eyes and found herself staring into Nightmare Moon’s.
“I don’t want to hurt you, Luna. I know the real you must be in there somewhere: your pride, your ambition, your righteousness. I don’t know what Sola did to the Elements, but you’re too strong to let them beat you. You’ve got to fight them! I’ll help you any way I can.”
Luna seemed to waver with indecision for a long moment. Then she lashed out with her hooves, pushing Nightmare Moon’s aside. Another hard strike to the chest plate of Nightmare’s armor shoved her back. Luna’s horn flared with magic and she shrieked, “My mind is clear! You’re the one who’s sick. But you’re nothing. Nothing! You’re only a stupid idea that I carried too far. I’m still Princess of the Night, and I still have power in dreams, and I don’t have to put up with phantasms the likes of you!”
The silvery light burst from Luna’s horn, spearing Nightmare’s sensitive eyes. She flinched and tried to shield herself with an arm. She cried out, “No, wait! Please!”
A wave of magic expanded out from Luna, and Nightmare Moon was gone — blown away just like a leaf on the wind.