Spike threw open the basement door and almost ran into Rarity. “Rarity! What happened down there? I heard shouting, an explosion, and… what’s that ticking sound?”
“I honestly have no idea, but I’m supposed to stall you for a minute. We’re both intact! Twilight just wants to check to make sure that her horn isn’t dangerous.”
Spike’s eyes opened even wider. “Her horn? What’s wrong with her horn? Is it like the poison joke thing? Or what?”
“Well…” Rarity said, “When I left it was glowing violet, so I’m going to assume that it’s not that.”
“Violet?” Spike asked. “That’s not that color of her magic.”
Rarity looked over her shoulder. “Maybe more of an indigo, really. I’d have to get my color cards to be sure. But yes, a long way off from her normal magenta.”
“Okay,” Twilight called from the basement, “The Geiger counter’s needle is barely moving at all, so I assume it’s safe. Just come down and don’t touch my horn, just in case.”
Rarity and Spike headed down the steps, and Spike saw Twilight’s glowing horn. He blinked at it. “Um… Twilight? What did you do?”
“What I was trying to do,” Twilight explained, “Was examine one of the fundamental natures of the universe. Now, I didn’t wind up doing that, and for that matter I don’t know what I wound up doing, but for whatever reason I now have some sort of unusual magical energy inhabiting my horn, and I believe it is feeding on my magical energy, but I’m not sure.”
“Wait,” Spike said, “There is an unusual magical energy, inhabiting your horn, feeding on your magic? That’s bad! There is no way that’s not bad!”
“Yeah,” Twilight said. “Definitely. Creepily enough, it’s kind of comfortable. It doesn’t hurt, but it is keeping me from using magic.” As if on cue, the aura momentarily flared. “Yeah, I’m going to write Celestia a letter about this. Rarity, could you get the mayor to institute a quarantine around my house? Just in case it’s contagious.”
Rarity backed up a few steps. She hadn’t even thought of that! “Right. I’ll do that right away. Good luck!” she said before running upstairs. She barely reached the main room before running into Pinkie Pie.
“Rarity!” Pinkie declared, “I came as fast as I could, which isn’t as fast as I normally could, because my Pinkie Sense keeps-” For a moment, Pinkie spaced out and vibrated. “-going off for some reason. What happened?”
“Not right now. Pinkie, what do you know about setting up a quarantine?” Rarity asked, making sure that the fact that this situation was completely serious came across in her voice and manner.
“Nothing.” Pinkie said simply.
“Nothing?” Rarity repeated in surprise. “Nothing?”
“Yeah,” Pinkie said before momentarily vibrating. “Why would I know anything about quarantines?”
Rarity blinked. “Well… it just seemed to be the kind of random, nonsensical, and highly specialized knowledge that you would have.”
Pinkie Pie nodded sagely. “Sound logic, and I would have thought that same thing, but I don’t know anything about quarantines. You’d have to ask Fluttershy.”
Rarity blinked at this. “Fluttershy?”
Princess Celestia perked up when a letter appeared in front of her nose. Oh, good! A distraction from the endless drudgery that was royal paperwork. She immediately opened it. The letter was not what she expected. Instead of a heartwarming lesson in friendship, it was a description of a problem, how the problem came about, and a plea for help. She immediately wrote and sent her response.
Princess Twilight Sparkle,
I would first like to congratulate you on the usage of Starswirl The Bearded’s infamously incomplete notes to create such a spell, even if only in prototype. The casting issue you described is unique, to my knowledge, not something that I have ever heard, read, or had described to me. This implies a whole new school of magic, and possibly the most complex one since thaumaturgy. Please forward all finds on this topic to me so that they might be immortalized in the library.
As for your sudden condition, I have less good news. I will be blunt: I have no idea whatsoever.
The above answer would apply to most questions you have on the subject. Please keep me informed on this topic! I will do my best to find any answers at all.
~Princess Celestia
As Twilight finished reading the rather worrying letter from the Princess, she heard a knock on the door. She headed to it quickly, and found Fluttershy in an advanced, magically reinforced hazmat suit.
“Hello Twilight,” Fluttershy said meekly, “You… ah, you wanted to be quarantined?”
“Yes,” Twilight said, “there was a misfired spell, and the result was… this.” Twilight gestured up to her still glowing horn. The color hadn’t abated in that time; if anything it was a little stronger.
“Oh,” Fluttershy said as she debated this. “If it makes you feel better, it’s kind of pretty. Anyway, just don’t try to leave your home, and I’ll mark your door with an X.”
Twilight blinked. “That’s it? That’s all?”
“Well… no,” Flutershy admitted sheepishly. “We’ll also wrap up all your windows and doors in yellow caution tape and some medical unicorns will put up a quarantine field. Oh, and here,” Fluttershy handed Twilight an old radio with a speaker and a microphone on it. “If you need anything, even just someone to talk to, you can use this. Okay?”
“Yeah, thanks Fluttershy.” Twilight took the radio. “But, I have to ask, why are you the one that is setting up the quarantine?”
“Oh,” Fluttershy fidgeted nervously. “That’s kind of a long story. I’ll tell you some other time, okay?”
Next, it was Rarity’s turn to find the Hazmat-suited Pegasus at the door. “Just finished taping Twilight in?” She asked.
“Yeah.” Fluttershy said sadly. “Um, Rarity, since you were at ground zero, the doctor thought that you should, uh, watch your health for the next few days. Maybe a week. We’re hoping it’s nothing, of course, but if your magic does begin to act up, well, the doctors would like to know, okay?”
“Okay,” Rarity said, trying and failing to hide the worry in her voice.