The Key and the Lock

by Rose Quill

Rating: everyone
Tags: Slice of Life, My Little Pony: Friendship is Magic, Mystery, Spike, Starlight Glimmer, Twilight Sparkle, Discord
Length: 1316

Twilight and Starlight discover a twist in established magic.

Twilight Sparkle and Starlight Glimmer have finished working on the glamor spell for their friends, only to be denied the ability to cross through the mirror.

Continuity: Homecoming

Revised 11-4-17

Published 2017-01-29 04:20:01 UTC
Last updated 2017-01-29 04:20:01 UTC

The Key and the Lock

“So what about the inverse flux ratio of the portal?” I asked, jotting down a note on the parchment in front of me, hoping the growl in my tummy wasn’t too loud.

“We need to get an exact reading of that before we can start to factor that in, Starlight,” Twilight said, wings flexing as she stretched her neck. “But, at least we’re closer to figuring out the transitional rate and possible cause of the time difference.”

I looked over at the pile of crumpled paper in one corner of the library. “If you say so,” I muttered. “The glamor should resist most shearing forces, but since we’ve only tested it with the shear factor from teleport spells, we should probably test it in the portal next time.”

Twilight consulted a piece of paper on her desk. “It’s the first day of school there, so I don’t want to just pop over and cause a fuss.” A low growl sounded from across the room. She rose from her cushion and started trotting to the door an embarrassed look on her face. “But we should probably go get something to eat. I’m starving.”

I smiled at that, rising as well.

“You don’t say,”

“Argh!” I crumpled the piece of paper and tossed it to join the others. “There doesn’t seem to be any reason for the difference!”

“There has to be,” Twilight said. “It can’t just be random chance.”

“Unless they have a different Lunar cycle than we do, that’s all we have to go on.” I sighed. “Thirty moons,” I said. “Seems so arbitrary.”

“Star Swirl made the mirror,” the Princess said. “He couldn’t have made such a powerful artifact without some sort of anchor on the other side,”

“And anchors need to be a fixed constant in order to maintain cohesion.” I finished. We were rehashing the same ground for the third time today. “We should probably forget about the time dilation and just get ready to do tests on the glamor.”

She sighed, putting her quill down on the desk. “You’re probably right,” she murmured. She glanced at one of the windows. “Tomorrow,” she said, rising. “We’ll run a field test tomorrow. Don’t you and Trixie have a show tonight?”

I followed her glance in confusion and saw that the sun was being lowered. Nighttime was coming on quickly. “Oh my Celestia! I’m going to be late!” I turned and started to dash off before I remembered I could teleport. I charged up the spell, pictured my room in my mind and released it, being pulled almost instantly along a tight corridor that connected the point I was standing on and my chambers.

I hurriedly got dressed and teleported to the town square just in time to meet Trixie stepping out of her wagon. She smiled softly as she saw me and a slight blush rose to my face. I wasn’t used to people feeling like that when they saw me. Friendly smiles were one thing, but lately, Trixie’s smiles had taken on a different dimension. I wasn’t entirely sure how I felt about her beyond friendship, but seeing that smile did make my heart do somersaults.

“Are you ready?” she asked, levitating her hat over and settling it onto her head.

“Yeah,” I said. “It’ll be a relief after going over formulae and theorems all day.”

She snickered. “Serves you right for deciding to help that bookworm,” she said as she fastened her cloak.

I grinned back. “Don’t forget,” I mentioned, adjusting my scarf slightly. “Without that bookworm, we’d never have met.”

“You’ve got a point,” the show pony admitted. She trotted up the stairs to the backstage area, with me right behind her.

She charged up her horn, and shook out her mane, a confident smile replacing her regular calm face.

And the Great and Powerful Trixie started her show.

Twilight levitated the book up into its bracket, and the mirror flashed with magic. I turned to her, spell held in my mind and a bright glow coating my horn. “Ready when you are,” I said.

She nodded, spreading her hooves slightly to brace against the spell. “Go for it,” she said.

I closed my eyes and fixed an image in my mind of Fluttershy before releasing the spell with a surge of magic. I heard a gasp and opened my eyes to see what appeared to be a close facsimile of what could be Twilight and Fluttershy’s progeny. I fought to contain laughter as Twilight inspected herself in the mirror.

“Well, this is…oh horsefeathers,” she said, even the voice was different. Where Twilight had the comfortable speaking voice of a teacher, the spell had softened it to somewhere between that and Fluttershy’s soft tone. She was still an Alicorn - no magic of mine could conceal that - her coat had softened to a teal color and her mane had grown longer, losing it’s two-toned streaks and shading up into a rosy hue. The cutie mark stayed the same. Again, magical limitations.

“Well, it certainly works,” I said. “Still need some practice on the imaging, though. Picturing two ponies apparently combines their likeness.”

“That should be fine,” the Princess of Friendship said, flexing her wings. “Be back in a second,” she said, trotting towards the portal.

And rebounding off it.

“What?” I said, glancing up at the book. It was secure in its bracket. Twilight stood up and rubbed a hoof against the portal, sending ripples through it but unable to pass through.

“I don’t get it,” she said, rearing up to press both forehooves against it. “I talked to Sunset this morning, the pathway should still be open!”

I levitated the book from its bracket and put it back. “Try again,” I said, concerned. This was magic constructed by one of the most powerful Unicorns in the history of Equestria and powered by one of the most talented Alicorns of the modern ages' modifications. Everything said it should work, but it wasn’t.

And that wasn’t good.

“Still nothing,” Twilight said dispelling the glamor. “Spike! Spiiiiiike!”

The dragon trotted in a few minutes later, followed by Big Mac, Rainbow, Pinkie, and Discord. Apparently, tonight was their night to play Ogres and Oubliettes. “Yes?” he said, a little hurriedly.

“Nobody came in here and messed with the mirror today, did they?”

“Not that I saw, Twilight,” he said, fumbling with his stack of books.

“Oh, is the magic doorway not opening like it should?” Discord said, conjuring a door that opened ninety degrees off from normal. He pushed it open and stepped through. “Those things can be so simplistic.” He gazed at the mirror before frowning. “How odd…”

I blinked. I hadn’t known Discord long, but I knew that there wasn't much that he would consider odd. Before anyone could question him, he popped over to the mirror, appearing in a costume shirt of red with black shoulders and collar with a row of golden dots along it. He examined it from a number of angles, even looking like a photo negative for a second before stepping back, his costume disappearing. He did not look happy.

“It’s radiating Chaos magic,” he said. “And it’s not wholesome like mine.”

“Wholesome?” I muttered.

“Whatever is disupting the mirror,” he said, either not hearing me or deciding to not indicate that he had. “Is older and more evil than I ever was.”

Twilight and I locked eyes.

“Research?” I asked.

“And fast,” she said, yanking books off the walls faster than I had ever seen to pile onto our desks.

Author's Note

This is the last plot-involved one shot before Chaos Theory. The rest of the shorts are going to be mostly fluff, with the upcoming Cruise story, Valentine's day multichapter, and a glimpse at the SunLight bridal shower.

Hope to see you all there!