Twilight knocked twice on the plain door. It wasn't worthy of a princess, even a former one. Celestia had only allowed for the crown to pay for her accommodations in perpetuity if they wouldn't be too much of a drain on the coffers, Luna had done much the same, and so here Twilight was at what could generously be classified as a house.
The new sense she had picked up recently told a different story, however. Everything had a glow to it. Not overpowering, but impossible to ignore. Twilight puzzled over that, as most inanimate objects she encountered had little to no such aura around them. This house burned brighter than many ponies she had seen since the auras appeared.
The door swung open, revealing her old teacher. Her aura was very dim. Twilight wasn't sure what the significance of these auras were yet, but she knew it was worrying to her that Celestia was so faint.
"To what do I owe the pleasure, Twilight? Our usual visit isn't for another few days." Celestia asked as she stepped aside to allow her entry into the room. The inside of Celestia's home was lavish, in stark contrast to the exterior. She had been able to convince the crown not to spend exorbitantly on her, but had not managed the same for the citizenry. Expensive gifts from grateful ponies across the country adorned every available surface. Twilight remembered having to vet a few of the more advanced magical trinkets for safety personally. While it was no great secret to the public that Celestia was living somewhere on the outskirts of Trottingham these days, the exact address was stripped from all available listings. It was also publicly announced that all mail could be forwarded to the former princess by the palace after ensuring it was safe.
Nearly every gift on the shelf lacked any but the faintest aura surrounding them.
Twilight spent a few minutes exchanging pleasantries with her mentor, a few hours drinking tea, talking with her about the drudgery of court life, the comparatively adventurous life of her niece, her former students at the friendship school, and really everyone she knew that hadn't taken up a life in governance. After a particularly dramatic story about Flurry Heart's latest escapade, a hush fell over the room and Celestia's tone became a little more pointed.
"Would you like to finally get around to telling me why you came?"
Twilight stiffened without saying a word, wings clamped firmly to her sides lest they pop wide open with nervousness.
Celestia walked over to her keepsakes and took a small but expertly crafted tiara in her magic. It was one of the few items there that had a glow about it. "I don't know if she showed you this at the time, but Rarity actually made this for me. 'So I could feel like a princess anytime I wanted to reminisce, without having to steal the regalia back,' she told me. I think it really looks great on me." Celestia sat back into her chair and put the tiara on with practiced grace from years long past, and for a moment Twilight saw a gently waving pastel rainbow instead of the loose pink bun Celestia was keeping her hair in today. "I get the impression you need me to be the princess for a few minutes today."
Twilight nodded, still mute. As she fixed her gaze on Celestia's jewelry, a quietly terrifying thing happened. Its glow visibly faded and winked out to almost nothing, leaving it as inert as the other gifts on the shelf.
Celestia reached out a hoof across the table to pat Twilight's shoulder. "I'm here for you, Twilight. I'm one of the only mares alive that can truly say she will always be here for you."
"Everything glows. Everyone glows. I have no idea what to make of it. The tiara in your head is dimmer than when you put it on, but it glows too," Twilight blurted out. As she did, Celestia removed the item from her head to inspect it. "I glow in the mirror, too. It's going to drive me crazy if I can't get to the bottom of it. I was hoping you might know something."
Rather than respond to the question directly, Celestia examined the ornament between her hooves further. "Hm," she mused. "It has lost most of its light in the last few moments. That's interesting."
"You can see it too! Tell me everything!" Twilight leapt forward in a way that she normally couldn't be seen doing due to her station, planting both forehooves firmly on Celestia's shoulders.
Celestia calmly returned the tiara to her head. "That glow, as far as I can tell, is a side effect of holding the power of the sun for as long as you have, or as long as I did. Light reveals, and sometimes not in the literal sense."
"What does it reveal, though?"
"In this case, that would be the force we call 'destiny.' Anything or anypo–" Celestia caught herself using the outdated phrase. "creature. Any creature with a significant destiny glows brighter than those that do not."
Twilight felt tears beginning to well at the corners of her eyes. "Then why am I so dim? Why are you so dim? I don't like to gloat, but we've done so much during our lifetimes! And our destinies aren't 'significant' compared to other creatures'?"
Celestia shook her head and gently brushed Twilight's hooves off her shoulders. They landed on the table between them limply with a thunk. "That's not exactly how it works, Twilight. When I first started seeing it, I couldn't look at myself in a mirror for years. It fades over time."
"How do you suddenly just stop being important like that?"
"Well to start, you give up your throne to a worthy successor."
Twilight gasped slightly. Celestia continued speaking. "Destiny isn't a fixed path, even if sometimes it feels like it is. Everything in our world has some ability to exert influence over it. To change it in their own way, big or small. But it has a cost. Every act of agency uses some of your destiny. And it never comes back. We've had very exciting lives, so we've used a lot. Thankfully, we had a lot to use."
Twilight thought about that a moment, then cocked her head. "How does an object have agency then? The tiara did something to use most of its destiny just now."
"Objects that just passively exist use theirs a little differently. They don't typically get much, and they usually use it to just exist. But sometimes an object is so influential by just existing that it has a destiny brighter than most ponies."
"Like your house."
"Yes, Twilight. Because my new home will likely play host to a great many conversations of weight: important things that will shape the realm, and the space such conversations occur in can frame how you view them. Or," Celestia placed her tiara on the table as almost all of what remained of its aura faded even faster, "maybe seeing your mentor put on the crown for a few minutes makes you take her words more seriously than you otherwise would have. And the weight that moment carries is heavier than the average object's general existence."
Twilight couldn't suppress her next question. "What's the brightest object you've ever seen?"
"Brightest single thing? Let's discount the obvious ones. The palace, the Elements of Harmony, various famous works of art. Are we counting plant life as things since they don't move?"
Twilight nodded.
"Then the brightest thing I've ever seen was a very old, big, beautiful tree in the palace garden. It's still there, if you haven't done any significant landscaping."
"A tree? I've been to the garden since I started seeing these things, and most of the plants are dull out there."
"Oh, I was baffled for the longest time why it was so bright. I was even more baffled when I saw it expend nearly all of its power all at once." Celestia smiled wistfully. "A scholar from Coltsterworth was passing through Canterlot on his way to a university in southern Equestria, and I'd invited him to stay at the palace for a few days. If you're curious, his aura was also quite bright. On his first morning there, he was resting in the gardens after breakfast, under that enormous tree. Between him and the tree, I could scarcely look out the window at him, the light was so blinding. But I was certain these two destinies meeting might offer an explanation for why the tree's presence was so strong. And if I'm being honest," she said as her grin turned mischievous, "he was easy on the eyes, too. All at once, the tree's aura dimmed to almost nothing, as an apple fell from the branches and impaled itself on his horn."
"The tree that Sir Neighton was sitting under when he discovered gravity is in the palace garden? I would have visited!"
Celestia nodded and laughed. "I was furious at the time, too. All that anticipation, and this grand act of destiny is pelting a nice stallion with fruit? Not even 'pelting!' A single inconvenient apple! It wasn't until he caught me looking out the window and ran to tell me his brilliant discovery that I realized how much the world we live in had just changed. Sir Neighton's destiny faded somewhat in that moment, but not as much as I would have expected. He was truly a marvel."
Twilight sat back in her chair, relaxing for the first time in several minutes. "So I shouldn't be worried about what's left of my destiny, then?"
Celestia took a small sip of tea, the gingerly put it on the table with a light clink. "Oh, you should be panicking quite frankly."
She immediately complied. "What? Why?"
"Because it takes a lot of that destiny to shape world events. You still have a robust reserve by most standards, but you'll be needing to use it every day until you take off the crown." Celestia's gaze turned to steel as she looked Twilight dead in the eye. "You will need to use every ounce of guile and cunning you have to influence things as subtly as possible, to avoid burning out everything you have."
"But the tree's influence was subtle, or your tiara–"
"Even a subtle change caused by an object requires far more than you would typically expect."
"How do I keep from running out?" Twilight asked, scared.
Celestia returned to her more casual, calm demeanor like it was easy for her. "First, you need to accept that you simply will run out eventually," she said as she stood. She circled around the table and placed a comforting wing over Twilight's shoulders. "One of the reasons I left the throne when I did is that I didn't find it tenable to continue with how little I had left in reserve. Don't let it paralyze you. If you can do something good without causing something terrible, do it."
"Anything else I should know?"
"Surround yourself with other ponies who have strong destinies. There's a very good reason I almost always had at least one personal student studying with me." Celestia nuzzled the back of Twilight's neck. "Twilight, when I met you all those years ago, and you were scarcely taller than just my hoof, you shined like the midday sun in a cloudless sky. Brighter than I've ever seen in another pony. I knew the moment I saw you that your life's story would be the stuff of legend. I don't doubt you will be able to find other ponies like that, if you just look."
"I did see a few like that when I went to the School for Gifted Unicorns. I remember one filly in particular who might be promising."
"Start inviting her to private lessons. I'm sure any foal there would be thrilled at the chance. Who is she?"
"An adorable young lady. Pink coat, orange mane. Her name's Luster Dawn."
Author's Note
So, all none of you who have read my Junk Drawer entries will know this is one of them, lightly edited. You may also know that I said I wasn't going to post this as a standalone. I changed my mind. It's its own thing now. Still probably not gonna make followups to this, just had some creative juice flowing here and wanted to let it out.