The basement of the Golden Oaks Library.
Later that evening.
Twilight and her friends returned from Cloudsdale. (It was the dark of night—they wouldn’t learn about the monster attack, about Blueberry Frosting, until the next morning.) For the most part, they were happy: They had seen a wonderful city and had gotten to walk among the clouds. And Rainbow Dash had saved the day—and Rarity—with her legendary move, silencing her critics and earning her a dinner with her idols.
The only hiccup had been Spike: the cloud walking spell hadn’t worked on him, so he had to spend the day tethered to Twilight like a toddler, always fearful that he would fall off of her back. But now he thought he had a way to fix that problem.
“Twilight?” Spike called out from the top of the stairs leading to the basement.
“Come on down, Spike,” Twilight called back.
Spike descended, to see Twilight on a stepladder. She was wearing her lab coat; a pair of smoky goggles were perched over her horn. She was busy adjusting a small device that was attached to Sonata’s statue. It was a cube a couple of hooves across, with golden edges and clear crystal faces. Small colored lights danced within the cube in a set pattern.
Twilight nudged the cube over just a bit, then took her hooves off of it and looked over at Spike. Seeing that he was holding the book she had bought him in Cloudsdale she asked, “Did you find something?” Spike noticed that the cube was sticking to Sonata’s chest, right over her hooves and the Suppressor.
“You bet!” he declared, walking over to a workbench and spreading open the book.
Twilight climbed down the ladder to join him.
“The pegasi really do remember a lot more about dragons than the other tribes,” Spike said. “This says that dragons enchant their breath—”
“—Which we already knew,” Twilight interrupted.
“—Which we already knew,” Spike said in a slightly annoyed tone, “but they store their magic in gems. And gem-based magic is the easiest way to affect dragons.”
Twilight led Spike over to the statue, saying, “Starswirl studied dragon magic. He was also believed to have written a now-lost book all about gem-based magic, which before now I thought was completely unrelated. Now take a look at this.” She levitated Spike up so he could stand on a platform that had been set up for that purpose. She then reared up and tapped the corners of the crystal cube in a specific way.
The lights inside the cube expanded to completely fill it, then projected outward between them, forming a larger-than-life holographic projection of Sonata’s stone hooves. Twilight began moving her hooves over the sides of the cube, manipulating the projected image.
“Is that earth pony magic?” Spike asked. “Unicorn artifacts usually require unicorn magic to manipulate.”
“Well, the original Examination Cube was one of the eight enchanted items created by Mage Meadowbrook in the Classical Era. It’s usually used to view a sick pony’s organs. Scholars have long claimed without a shred of evidence that Meadowbrook was a unicorn. The current consensus is that we don’t know what her tribe was.”
Spike frowned on hearing the primary use of the Cube. “Oh, I remember that now. It was used on me when I was little. A lot. This unicorn married couple wanted to write a whole book on dragon anatomy based on me. Celestia discredited them after she caught them gassing me for dissection.”
Twilight nearly knocked Spike off of his platform with the speed of her whiplash. “What?! How come I never heard about this?”
“You were in the hospital after you sprained your ankle,” Spike said. “I didn’t even understand what had happened until years later.”
“You, uh…don’t mind me using it?” Twilight asked, looking sheepishly over at him.
“‘Magic is a tool,’” Spike said, quoting one of Twilight’s more frequent sayings back at her. “And Cubes have saved tens of thousands of lives.”
“Which is why I’m trying to use Ponyville Hospital’s Cube quickly, before somepony needs it,” Twilight said. She made some more adjustments to the device, which caused the hooves and body of Sonata to fade away, leaving only the pendant.
Removing her hooves, Twilight faced the image. “The anatomist Von Pretzel developed an entire class of spells for manipulating Examination Cube images. I’ve had to do a bit of work adapting that for images of stone instead of flesh, as well as to correct to the forms that stone was in before the enchantment.” A complex web of laser light projected from Twilight’s horn onto the image, shifting it from stone into a bronze oval surrounding a light purple stone.
“Amethyst!” Spike exclaimed. “That’s in the book!”
Twilight levitated the book over so that Spike could hold it open for her, a rather frequent job of his. After flipping back and forth between a couple of pages, she said, “this is sort of reading between the lines, but it looks like amethyst is good for storing unicorn spells.” She continued casting spells on the image, causing all sorts of arcane symbols to appear in the air, symbols which she then copied into her ubiquitous notebook. “Hold on,” she said when she was finished. She lifted both Spike and the book up with her magic, depositing them on the ground near the workbench. Spike put down the book as Twilight shut off and removed the Cube, carrying it down the stepladder to place on the workbench.
She read the entry in the book a few times. “So, would you like a necklace of your own?” she then asked with a knowing smile. “Not a Suppressor, but a way to cast a long-term spell on you. Any single spell you want I can put it in there, and it will actually affect you.”
“Would I?” Spike replied with a grin. “You’ll be able to switch out the spells, right?”
“Yes, given enough time,” Twilight said. She pulled out a sheet of parchment, her quill and ink so she could begin working on the enchantment equations. “A few hours to cast each one, I’d say. Cloud walking one week, super strength for another… That was one thing I really missed out on during my school days—trying out spells on other unicorns, and them trying theirs out on me. I was too powerful to team up with anypony.”
“Do you expect me to be responsible with my newfound power?”
“Oh hay no! We will Science this business to the Badlands and back, Brother!”
She then levitated Spike up so they could do a proper “high hoof”, laughing the whole time.