Sunset paced through her room for the thousandth time, eying everything she had prepared. It looked as though someone had accidentally let a small tornado into the cramped space—the contents of every drawer and every shelf had been dumped onto the ground, so thick she couldn’t see the carpet.

Being Celestia’s personal apprentice could have brought luxury, if Sunset Shimmer was another kind of pony. But Sunset wasn’t the sort of pony who had taken the position on political appointment. Sunset Shimmer was a doer.

Though the rest of her room was in chaos, the bed had been tightly made and cleared of everything but the tools she would bring. Several densely-packed scrolls of spells she had copied, a fresh pad of paper and ink. Most expensive of all: a camera and a dense roll of film. The camera weighed nearly fifteen pounds and would take up half her saddlebags.

Taking drawings and notes simply wouldn’t do, not where she was going. It’s been over a thousand years since anypony has had this opportunity, she thought. And I won’t be pressed for time like Cover.

Princess Celestia wouldn’t do what was necessary to keep Equestria safe. Well an immortal Alicorn might be content to sit back and wait for the inevitability of fate to roll over everyone and everything Sunset Shimmer loved, but her apprentice was another matter. Sunset would stop the tide.

It was early in the morning by the time Sunset slunk out of her room, shutting the door with a soft click. Even so she held still outside, wrapped in a thick brown cloak. She heard nothing—no guards, no sign of Celestia watching her. Maybe she could do this.

Sunset Shimmer had already memorized the map, so there was no wasting time getting lost in Canterlot’s labyrinthine tunnels. Her destination was well hidden, but that didn’t matter. Sunset was Celestia’s personal apprentice, there was nowhere she couldn’t see, nothing she couldn’t know.

Well, there was one thing.

Once she made it to the second level of the basement, lower even than the dungeons that saw no more visit than the occasional school trip from the city far above, Sunset broke into a canter. The castle’s guards would have no reason to be patrolling so far away from anything important. There were no riches down here to steal, no important ponies to hurt in their sleep, nothing but the old armory with its rotting weapons and endless rooms filled with stored food.

The route down to the crypt was protected by a thick stone door, covered so thick with dust that she had to puff on the puzzle of runes in order to make them out. Sunset recognized the solution at once—the door wanted a simple mathematical concept central to magic to be spelled out in ancient Equestrian. So she tapped the symbols in that order, smiling smugly to herself. The door began to sink into the floor, rumbling and grinding against the stone.

Here it was dark, no trace of the brand new electric lights of the top levels or the glowing crystal of those further down. Sunset lit her horn, then continued onto ancient stone floors caked with dust. Her steps echoed here, reverberating strangely in the cramped space. She slowed, concentrating on a new spell, and with a flash the sound around her became muffled. She could canter again without producing a racket for any of the night’s janitors to hear echoing from the depths.

Eventually she reached her destination, a wooden doorway with hinges so rusted they crumbled away as she touched them. Even so, the writing on the door was quite legible. “Clover the Clever, Private Workspace. Do Not Disturb.”

Celestia never gets rid of anything, Sunset thought to herself, appreciating the ancient woodwork. Every generation she just builds the castle taller, and all the old places get lost underground. I wonder if Canterlot is even built on a mountain.

That mystery would have to wait for another day.

Clover’s old laboratory was a treasure of ancient Equestrian science. Gas burners still rested on their stands, trays of chemicals sat still sorted according to the ancient families of air, water, fire, and earth. Motheaten shelves slumped under the immense weight of tomes bound in something that smelled almost like flesh.

Her target sat at the far end of the room, covered with a cloth and propped against a stone wall. Sunset paused as she made her way across, lifting a faint glowstone from her pack and setting it down on a sturdy table. She walked straight up to the thickly covered artifact. The cloth didn’t lift up and off under her magical grip so much as crumble to ash and carbon, fluttering down to the ground to land in a pile.

In front of her stood Starswirl’s Metastable Spatial Claudication, a masterpiece of ancient engineering. It had been made into the shape of a glass mirror, rimmed with dark metal that looked like a horseshoe. Exactly eleven enchanted crystals rimmed the outside, each one still glowing with their own internal light.

As she got closer, she watched the pile of dust and torn cloth be drawn up into the air in front of the portal, as though it were the drain at the bottom of the tub. Air flowed past her, swirling around and around, outlined in ash and debris as they trickled through what looked like glass.

Sunset’s unicorn senses were not fooled. Just because the mirror looked like glass didn’t mean there was any glass involved.

“So, it has come to this,” said a voice from behind her, slow and sad.

Sunset jumped, nearly tumbling forward through the portal. She stopped a few feet away, and several hairs of her mane began to drag towards it. She could feel the pull of gravity dragging her sideways. She turned slowly, deliberately, as though she’d been expecting interruption.

Princess Celestia looked weary, her mane disheveled, and there were bags under her eyes. Celestia always seemed sad at night, for reasons she would never say.

Sunset Shimmer found she no longer cared. “Yes, Princess.” Sunset looked right up into Celestia’s eyes. Where she found the courage to defy the one who ordered Equestria itself, the one whose will set the sun in its march and ended day with night, she couldn’t say. Maybe it came through the portal, sent by the supernal beings who lived there. “Somepony has to act to protect Equestria. If you won’t help me…”

“Sunset,” Celestia reached out with one hoof, as though to pull her into an embrace. “You know it isn’t that simple. I tried to explain—”

Sunset pulled away, backing towards the portal. Her tail lifted from behind her, drawn towards the portal. She ignored it—it wasn’t pulling her in. “No! You explained, Princess, but all I heard were excuses. You say that isn’t how it works, you say I’m not ready to know what you know… to be what you are… but you don’t have a choice anymore! You’ve known what was on that scroll for centuries, and what have you done about it? Old weapons rotting away in a castle that nobody remembers how to use. You’ve betrayed us, Princess.”

Celestia reacted as though she’d been struck, eyes wide and watery with shock.

“Look around you, Princess! Equestria’s complacent! How much has changed in the last ten years? The last fifty? We know what’s coming, and we don’t do a damn thing!”

“We can’t,” Celestia finally said, her voice weak. “Sunset, I’ve done more than you know. If you would—”

“I won’t!” Sunset was shouting now, louder than she’d ever dared talk to the princess. This pony had the power to burn her whole body to ash in seconds, the power to kill even the mighty dragons. But that didn’t matter—even a princess was vulnerable to the truth. “Princess, I’m not going to let that prophecy come true! Knowing the future means we can change it.”

Was that a tear trickling down Celestia’s face? “Sunset… I’ve lived long enough to watch ponies I love destroy themselves in search of power.” she looked up, as though she could see through the ceiling to the sky far above. Her voice broke, and the monarch of all creation whimpered like a frightened child. “I’ve done everything I could to teach you. Don’t be like her!”

Sunset backed towards the portal, letting it swallow her tail completely. She was not dragged inside, as she’d expected. The pressure was gentle, and not painful. She could easily pull back if she wanted to. She had no intention of retreating.

She jumped. The last thing Sunset saw was Celestia reaching for her, tears streaming from her eyes. Then, nothing.

Sunset dragged herself through the void. Whatever she had been expecting from the inside of a rift, it wasn’t this. Maybe there would’ve been some swirling lights, or maybe an overwhelming flash of magic that would knock her unconscious. But if any of that had happened, she hadn’t noticed it.

Sunset Shimmer stood in a blasted gray waste, with soil blackened and charred and no trace of living plants. There were occasional bits of twisted metal on the ground around her, and a harsh wind seemed to always blow in her face, pushing her back.

Worse than any of that, was the missing magic. Sunset Shimmer could not sense even a flicker of magic from around her. All the power in the world seemed concentrated in her own body and the enchanted objects she’d carried—precious little.

“Sooner… I get through this…” she mumbled, and the words came slurred. Sunset found she couldn’t focus on anything that was more than a few feet away from her. Couldn’t move too quickly or else fall over under the disorientation. Couldn’t think of anything more than her immediate needs. Maybe there was enough latent magic in her body to fuel a single spell. But what could she do?

Clover the Clever’s magic had to be working! The ancient masters did not fail. In some ways, Clover’s impact on spellcraft was even greater than Starswirl’s.

Was Celestia afraid of what I would become? Sunset found herself thinking, as the world started to spin. Could she have changed the spell so the portal would never let me out? Am I… trapped here?

Sunset stopped walking, falling to her belly on the sandy ground. To her surprise, she found red spreading out from around the place where she’d fallen, and the ground felt almost warm under her touch.

Maybe… I can rest here… Sunset looked up, searching for the sun. She found it far away, a distant flame tracking slowly across the sky. Damn you Celestia… I only wanted to help…

Time passed in a blur. Sunset drifted in and out of consciousness. With every successive vision, she found she remained awake for shorter and shorter. Each image brought more pain, more sickness. She lay in the dirt without moving in a pool of her own vomit and blood, waiting for the portal spell to end.

Eventually she saw movement. Thin, graceful limbs, strong arms lifting her up. They placed her on something, and her whole body screamed in protest at the pain. They muttered words in hushed voices, words she couldn’t understand. She moved.

Sunset couldn’t see anymore, not more than a faint, dark circle. I’m dying, she thought, and by then all the bitterness at Celestia was gone. She was trying to save me.

Sunset looked up at the sky as she was moved on the back of a sled. She saw towering structures, stretching far out of sight. There were machines of a complexity she couldn’t understand. Flat faces without fur, voices of panic and urgency.

Then nothing.