Author's Note
The story, after its initial "break", is backwards. Read from the bottom to the top, last sentence of each paragraph first. It can also be read forwards to back.
Bigger spoiler on insight into the spell:
On a surface level:
It is supposed to send one's body back seven times from the time of injection. But, in fact, it sends recipients back to their young childhood. The mice went back to their childhood which was close to seven times from the time of injection.
The spell interacts badly with magic, as Starlight discovered. Both her mind and body aged backwards to her childhood.
She would have died without Redsky's meddling, since the spell was completely off. Later, the spell bubble leaked.
Eternal Rest, Eventually
Starlight Glimmer
Rest in Peace
- A friend who gave her time to the world.
- Bravely attempted a bold spell. We look forward to her return.
- Open not this casket of stone. Monitor its bell. In time, for its occupant, all should be well.
And everything happened again.
Then Starlight was past the lucid point.
"Seven lifetimes. Isolate me until I complete my decay! Magical creatures react differently than the rodents! Because of the fluctuations. Not only I will lose my mind, so will anycreature nearby!" Starlight frowned, "This will cause dementia!"
"That's just dementia."
"I saw what happened to Redsky Delight. It came through. Twilight. I'm living backwards and forwards and the spell bubble won't always hold. Holes in the mind; losing the present and focusing on the past--the timenado will spiral out."
"A what?" Twilight frowned.
"We don't have long. I'm only lucid because I've reached the point where I almost went under with the magic... I might be twisting Equestria--at least this part--into a timenado."
Twilight pressed, "Why?"
Starlight insisted, "Bury me in least permeable rock--granite maybe--Maud knows better."
Twilight asked, "but why?"
"Bury me." Tears came to Starlight's eyes and she spoke when Twilight, alone, returned to the chamber. Twilight Sparkle had left a large blackboard indicating that Starlight was loved. Everything was clearer again. She saw through the veil. Starlight was old again.
Starlight reset.
Forgot where she was. She kept talking about the past. She had spent significant time in the chamber, studying never-eating self-sustaining Starlight. Redsky Delight lost her mind.
Then Starlight was a baby in a bubble and she couldn't understand any more.
But it was only a half-mouth gesture. She tried to speak to Twilight and the mare in the hideous stained toque who were studying her, entreating her. She was partially in the dream and partially without. Starlight, only a child at this time, didn't have full control.
Rocks were also immutable. Dirt, however, dirt didn't change. Then they stopped. The messages turned to threats shortly thereafter. And "Twilight--I see blurred figures and movement and I think you see me. We need to reverse this spell--" A message of: "I see you beyond", repeated again and again. While reliving her first Hearth's Warming Eve, she had blinked rapidly in Hoof Code. They thought they got through to her. They replaced a blackboard with messages for Starlight--quite often. Structures twisted and decayed to original components. The process had strange effects on the chamber. Twilight and Redsky could see Starlight's past, reflected in her eyes.
She couldn't correspond with him. Her best friend went: and Starlight cried. She didn't go to the magic school. But she'd been hidden away by her Celestia-fearing mother, afraid Starlight would be snatched from her family. She wanted to attend Celestia's magic school. She studied time magic. She fought Twilight across time. Then they weren't. She and Twilight were friends. And she was forgetting.
Everything beyond her magical bubble, her sustaining bubble, was a blur.
Starlight winced from the pain, but she'd been brought back from the brink where she was bubbling apart and nearly wobblety-split into multiple realities: or death--they didn't know the outcome for certain. Forever. But it also trapped her. Starlight wouldn't deny that. Redsky's magic had helped.
Fluttershy buried them. Those bearing innate magic... had trouble. Twilight tested animals with and without magic. And aged as normal. Mice reached their yearling stage.
Screams. Starlight and Redsky Delight bubbled. Magic twisted. "This cannae be what the lassie wants. Cud is in the fire now. Bringin' her out. She's runnin' too hot!" Twilight's protege tried something.
"She's... fading." Time ticked far past fourteen hours. Her excess magic shouldn't have encased her in that cocoon--at least not for this long." Starlight, shaking and feeling her brain matter beating like a mixing egg could barely hear Twilight Sparkle sigh, "The bubble should have decayed seven times by now--for the hours Starlight tested... fourteen hours." They waited.
Twilight warned, "Don't touch her while she's phasing: anything might happen!"
Starlight's timer for her magic reached the tick-down point of zero back where it was supposed to be for the reset. She was supposed to momentarily de-age.. but instead she was glowing and giving off heat--radiating it and shaking.
Redsky chortled, "We cannae all be creative Cozy Glow."
"Redsky Delight. My second-least favorite pony." A flat, twisted voice from Starlight.
A toque-wearing pony raced into the chamber.
"It's like when we slipped into the time stream--but even more localized." Starlight shouted. But then her head pounded and her body twisted in strange contortions and her magical field fluctuated, bending everything inside, making it glimmer and twist at right angles. "I'm all right."
Twilight called, "Starlight--"
Starlight's voice rang hollow: satiated with echoes. "I should not be able to return to a point further than seven times before injection of the radionuclides. Only a few hours."
Twilight asked, "What's the cutoff? How young?"
"The magic should kick in momentarily and you should see me aging backwards." Starlight snorted, "fine." Twilight didn't have to say anything. "Yes, I got better, but.... Of course I know ponies said the same about me after I nearly destroyed the timeline and brainwashed a village. Of course she's a 'reformed' fluffpirate, but we can't trust her impulsive insanity. Besides, you're taking risks--gallivanting with that madmare at your side." Starlight's sentence trailed, "And I'm more careful... than last time.... You don't know all there is to know about magic, Twilight, just because you're an ageless alicorn!" "Excuse me!", Starlight snorted.
"Remember why?" She paused. "Time magic is banned," Twilight said.
"We'll have seven times as much life, since it takes at least seven times to decay. Our bodies' unstable aging particles can be prorogued. Organs can be intertwined with radionuclides. Life can be extended using principles of radioactive decay." Gleefully, Starlight Glimmer pranced, eyes twinkling through creased, aged eyelids.
"We'll reset everycreature's age! Yearling mice reverted to babies a bit over a month after initial injection. Twilight--it worked!"
