Luna opened her eyes to a stiffness in the air. She blinked once and glanced towards the balcony where the last rays of sunset wormed their way in through a crack in the curtains. There, nested among the shadows, they touched upon the edge of an alabaster hoof.
“Sister,” she said, pushing off satin sheets and slipping out of bed, “I did not expect you so early in the dusk.”
Celestia sank further into the all consuming shadows. “Good evening, Luna. I’m sorry for intruding. I didn’t want to be alone.”
“Were the nobles such a chore this day?” Luna asked, stretching like a cat in the dark, “You are too soft on them. They will not give proper deference without discipline.”
“I can’t help it. I’ve always been that way with children.”
Luna gave her sister a sideways look but the other failed to notice and she made her way around the room, carefully avoiding the sliver of light from the balcony. “I suppose you never have changed much.” She said, knocking the curtain closed with a sweep of her hoof and at the same time causing the candelabra to burst into low blue flame.
Shadows danced in the dim light as if debating whether to terry in the two sisters’ prescience. They hovered there, flicking side to side in a nonexistent wind before leaping from the walls and climbing up Luna’s legs. There they coiled inward upon her frame, wrapping her horn to hoof in inky bandages, before bursting outwards to form a loose silken robe. Within moments the room stilled and the finer features were visible to the two alicorns. Luna, now properly attired and styled, turned to face her sister fully.
Celestia giggled at the display. “Showmare.”
Luna clamped down on her pout before it could fully manifest. Instead she let out an indignant huff and walked past her sister to rummage through a muraled cabinet recessed in the wall. “Tell me: what is it that has brought you to my chambers this evening?”
Celestia pulled backward, rubbing her foreleg with a hoof and looking at the ground. The flickering blue lights of the candelabra made her eyes seem suddenly sunken and old. “It’s nothing important. I’ve just been feeling out of sorts.”
Luna leveled her with a flat look. “If there is anything that I have learned in the hundreds of years I have known you it is that you brooding in my room, while I sleep, is not ‘nothing’.”
A mirthless chuckle escaped the solar diarch. “Credit where credit due I suppose. Twilight came by.”
Luna looked askance at her sister as she rummaged through a cabinet, the clinking of glass almost musical in the still room. “I would think that cause for celebration. Is she not well?”
“She asked if she was immortal.
The rummaging stopped. “I see. Did you tell her about...?” Teal eyes asked the unspoken question, and Celestia looked away in shame.
“No. How could I? If she knew…”
“She would understand. It was a hard time.”
“Of course she would understand, she’s a good pony. One of the best even. But things would change. I saw a hint of that today and… I don’t think I could bear it.”
Luna cast one more sidelong glance at her sister before extracting a silver bottle and two glasses from the cabinet. “Even now, you underestimate her. She is stronger than you know-- or perhaps it is you who still fears the past?”
“You don’t need to worry about me, Luna.” Celestia said with a dismissive wave of her hoof, “I made my peace with our actions long ago.”
Luna’s brow leapt skeptically skyward, but she recovered quickly. “If you say so.”
“It’s just that sometimes I wonder--” Said the other, accepting a proffered glass, the contents invisible save for a faint sparkle in the dim light, “what if there had been a better way? One that didn’t cause so much suffering. One that didn’t...” She trailed off, then downed her drink, pushing past the lump in her throat. “Everyone lost so much.”
Luna gazed into her own glass, opting to swirl it around in her magic rather than drinking. “We did the best we could. Even if we did not, the past cannot be changed and we must move onwards. Let it go. We’ve both seen what happened to the others. What happened to me.”
“I’m not sure that I can.”
“Please try. If not for your own sake, then for mine?”
“I-- I’ll try. Just don’t hate me if I can’t.”
“I could never hate you sister.” Luna wrapped Celestia in a hug, the other alicorn clinging to her tightly.
“History begs to differ. I seem to remember you broke my favorite vase.” She grinned at her joke, but when Luna’s only reaction was to squeeze her tighter she let the expression fall. “Sometimes I wonder-- after everything I’ve done, after everything I’ve done to you, how you can say that.”
For some reason that caused Luna to laugh. “How about this: if you never hate me, then I shall never hate you. Is it a deal?”
In the face of such a foalish proposition Celestia barked out a laugh of her own. “It’s a deal,” she said, wiping the moisture from her eye, “but you can’t forget my birthday again.”
“That was one time! Not even Discord carries a grudge for so long.”
“I think you would be surprised what our draconequus friend carries with him.”
“Perhaps I would. There are still many mysteries in the world.” Glancing down at her sister's barrel she commented, “One of them being how you still fit into that necklace. Especially with your diet.”
A pillow soared at the princess of the night and it was returned twofold, chasing the other alicorn out of the room.
Laughter echoed into the hall as Celestia paused halfway through the door. She looked back with a small smile. “I’m glad I have you back.”
Luna, wreathed in shadow and scattered feathers, returned the smile. “I would wish for nothing else.”
The door clicked softly behind Celestia, leaving Luna in the dark to stare after her sister. She looked down at the soft glow of sunlight as it crept in at the edges of the curtain. Peering after it, she watched as it dimmed and then faded, saying nothing as darkness fully settled in on the room.
Luna heaved a sigh and flared her horn. The midnight blue glow saturated the room and seemed to cast more shadow in the already dark room. After a moment a sliver of moonlight crept in from the balcony, slicing through the gloom.
“We shall have to be more careful in the future,” she said, bolting the door with an effort of will.
A series of lamps along the wall sprang to life as she crossed the room highlighting floor to ceiling bookcases filling one corner. She pulled a heavy tome from one, barely glancing at the crescent moon on the cover, and moved to her desk-- pointedly ignoring the large mirror beside it.
The book made a heavy thud as she set it down. It was nearly as large as a platter and bound in blue canvas. Various ribbons and sheets filled with runes, formulae, and other notes were jammed between the pages. Flipping it open to a red ribbon, she studied the diagram inside and its surrounding characters.
With a word she channeled her magic through the lines on the page until they glowed with azure light. Radiating and pulsing it lifted off the page and hovered before her eyes. Then with a mental push the sigil floated forwards and attached itself to the glass of the mirror before fading from view.
The mirror was as tall as she was. Rimmed in onyx and inlaid with alabaster carvings, it had been a gift from one of her generals soon after her ascension and had reflected her immortal beauty for hundreds of years.
Now it served a different purpose. Setting the book aside Luna took a deep breath and regarded her reflection critically. She noted the tiny features that had been nearly imperceptible in the dark: wrinkles at the corners of her eyes, a dulling of her pointed hooves, the fading of her midnight coat. Her regal bearing was unblemished but she seemed, to the careful eye, worn.
She sighed and as her magic flared her appearance smoothed out. The edges of her hooves became sharp and crisp, and her coat gained a more glossy shine. She nodded when it was finished, looking down to note the same changes in her physical appearance, before turning her attention to the whole of her reflection.
She looked just as she had after regaining her full power. Tall, regal, powerful. Brimming with youthful vitality. Exactly as I should be remembered, she thought, Aside from one detail.
She regarded her reflection as it stood perfectly still. No motion of hers now transferred to it, it seemed a static image of her save for its eyes.
The eyes had changed color. They were comprised wholly of a blue so deep that she could see galaxies spiraling in their depths. As she looked she felt herself falling into them, the infinite void pulling everything into themselves like a starving wendigo feverishly looking to fill the gnawing emptiness in its belly.
Or, conversely, like a vessel waiting to be filled.
“Tantabus,” Luna said, causing her reflection to blink, “How goes your progress?”
“Mistress,” it replied, bowing, “This one has assimilated up through the siege of Deepwood Pass.”
“So little?” Luna sighed, “‘tis not even of the Discordian era. How much longer will you require?”
“At the current rate, it will require an additional forty-three years to fully process all of your memories.”
“So long..?” Luna asked. She began pacing before the mirror, mumbling to herself and momentarily forgetting the Tantabus. “Do we have enough time? Can we put everything in order? If we should increase the potency of the potions and remain in the Dreamworld longer… Thirty years-- perhapse thirty-five… But forty? Can we manage it?”
“Mistress,” the Tantabus broke into her train of thought, “If thou woulds’t prefer, this one could exclude thy time on the moon and gloss over the more mundane of thy memories. It could reduce the allotment by no less than fifteen years.”
“No,” Luna shook her head, “you are not a journal. It would be pointless if you did not truly know the emptiness.
“And stop calling yourself 'this one.' You are as alive as I can make you. Refer to yourself as a pony would.”
“Is that an order Mistress?”
Luna chewed her lip for a moment as she regarded the Tantabus. She searched the expressionless face for any hint of emotion. “Yes. It will be good practice.”
“Very well Mistress, this one-- I will do so.”
“Good. And another thing.” Luna said. She laid out the tome in front of the mirror, turning to a recent page crisscrossed with arcane formula. “Memorize this.”
The Tantabus looked at the pages, scanning from top to bottom for several minutes before it turned back to Luna. “I have finished. What is it?”
“This… this is my gift to you. A way to be free. A spell to be rid of my-- your memories. Or, if you wish it, a way to end your own existence.”
The Tantabus looked at Luna quizzically. “But,” it asked, its brow furrowing. Its expressions had made remarkable developments over the past several months. “Why would I need such a thing Mistress? I was created to serve you.”
“I did not create you to serve me. I created you to replace me. Time weighs heavily on us all. I do hope you will never use it, but in time it may be a comfort to know that it is there. There were moments when I…” Luna shook her head. “You will understand in time. Suffice it to say that I have deemed it necessary to provide you with... options should you want for them.”
“... but mistress, I see no reason to have this spell. It can undo all that you have worked for, all that you have created myself for.”
“Indeed. Perhaps I do not believe that you should be eternally shackled by ghosts of the past.”
The Tantabus cocked it’s head to the side. “But mistress, unless I am mistaken, you are not a ghost. You are very much alive.”
“I am a ghost. A relic of the past. Held in place only by lingering regrets and now, without even those, I will fade away. The future is for the young, for those who can look forward. Life is too short to waste, too wonderous to squander and too long to hobble with regret. You are what comes after. You will persist even when I am naught but dust and faded memories. It is my purpose to teach you, to guide you, but you must move beyond me.
“My sister is… trapped. By the world and by her own hooves, and try as I might I cannot save her. Selfish as it may be, I ask that you help her. She will need a light in the dark when my own star burns out.”
“Is that the purpose that mistress created this one for? To guide your sister using your memories?”
“Yes… and no.” Luna said, absentmindedly floating the tome back to the shelf, “When my time is done you will have as much of me in you as I can give, but you will not be me. I wish for you to take on this task, but I will not bind you to it else I inflict my own suffering upon another. No, you must choose your own path-- and choose it willingly-- else it would have no meaning.”
Luna drew back the curtains and gazed out into the moonless night as the last whispers of sunset faded from view. She watched as the tiny vestiges of light cast themselves into the endless sky and were swallowed by the unending dark.
She watched as up above a star faded into view, a single guttering flame to stave off the all consuming void.
“Think on this, Tantabus.” Luna said, “Think on your future while you study my mind this night.”
And just like that she was gone. The drapes fell closed behind her with a rustle and the Tantabus was left alone. It stood in the mirror, a reflection in an empty room, a light with no source, a soul without form. It looked at the tome on the shelf and the journals beside it. It listened to the clopping of hooves outside the door as they grew still during the night. It watched the candles burn out, one by one, until all that was left was inky blackness. And still it watched, perfectly still in the glass.
The Tantabus stared after her as moments stretched into hours, it’s flowing mane pausing as if forgetting its purpose amid the creature’s thought.
“I do not understand, Mistress.” it said to the empty room, “Your words confuse me. How can one continue after one is gone? But this one will try to understand. This one will honor your wishes until it does understand. This one will follow your example. This one will care for your sister. This one will be her guiding star.
"This one will be... Polaris."