"A prison devoid of magic? I'm not sure if that's possible..."
Celestia nodded. "It's possible. I even know of a way to create a magic-less environment."
Twilight perked up. "Really? How?"
Celestia coughed. "It... ah... only works to absorb all the magic in Equestria. Hence why I'm hoping you'd have a better idea."
Twilight blanched at the idea. "All of Equestria? I'm fairly certain that is impossible. Or at the very least incredibly difficult."
Celestia considered six artifacts that, in another time, could do the job. Currently they were now surrounded by wards that may just make Discord hesitate. "Yes. Very difficult," she agreed.
"I have no idea where to even begin," Twilight admitted, pulling some paper and a quill out of her saddlebags. "Magic is just... everywhere! There is probably no place on the planet that's not saturated in magic." She started writing down ideas. "Maybe some kind of valve system..." she mumbled to herself, before shaking her head. "It would need a method of determining the difference between benign and malignant magic..."
"If worse comes to worse, we may need to resort to banishing across dimensions again," Celestia warned, instantly garnering Twilight's attention. "I cannot afford to give Tirek a chance to try again."
Twilight paused. "Tirek... I wonder if his method would work?" she mused.
"No!" Celestia was instantly on her hooves, startling Twilight with the sudden declaration and making her trip backwards onto her plot. Celestia cringed and sat back down. "I'm sorry Twilight, that was uncalled for. But no, we will not be using the same method as Tirek. I can't risk any future enemies learning how to do what he can do."
Twilight settled her racing heart and gathered her papers. "Yes... Of course Princess." she said slowly.
---
Celestia nearly leaped out of her fur and feathers when the door to her bedroom slammed open. Finding Luna storming in dragging a Unicorn in her magic, she grew concerned.
"Of all the idiotic, morally questionable, harebrained..." Luna growled, and flicked her horn. The Unicorn gave a startled scream when she was tossed at Celestia.
Thinking quickly, the Solar Alicorn caught the Unicorn in her magic just before she would impact her. 'Wait, isn't this...?'
"DO you have any idea what you could have done?!" Luna roared, getting in Starlight Glimmer's face and making the Unicorn scramble in futility to escape her. "Our Cutie Marks are our SOULS, you witless drone!"
Celestia cringed at the rage her sister was exhibiting.
"I hate ponies like you, who think the fact that they have power gives them the right to tinker with things they don't understand!"
At this point Luna's eyes were beginning to turn a familiar teal color, so Celestia decided an intervention was in order. "Luna!" she snapped. Luna blinked, her eyes returning to normal. "Perhaps start from the beginning? What happened?"
Luna huffed. "I realized last night while going over your notes that we had met this mysterious pony that Twilight seemed to trust in your vision, and that she was the same pony we had reservations about regarding her town."
"Okay, so I can guess you went to visit the town, but how did that escalate into... well, this?" Celestia asked, setting Starlight down nearby, but keeping a hold of her with her magic. Something about the mare had pissed Luna off, so she wasn't taking chances.
"When I arrived, I was greeted by the sight of every single pony in that town bearing the same Cutie Mark, that of a mathematical equal sign."
Celestia blinked. "Wait...what? How is that... how?" she settled.
Luna shook her head. "It gets worse. It wasn't just paint on their Cutie Marks. Their magic was also equalized with each other. There wasn't a single stars be damned difference between any of them, and as near as I could tell none of them had any talent in anything." She snorted. "The town was on the verge of famine due to inadequate food storage procedures and a lack of any kind of farmer or cook, never mind the state of their clothing."
She pointed a hoof at Starlight and growled. "She, however, was different. She bore the same Cutie Mark as the rest of them, but her magic was powerful... nearly as powerful as Twilight Sparkle's."
Celestia's eyes snapped around and she glared hard at Starlight. "A ritual to drain magic?" she asked, not looking at Luna.
Luna seemed to deflate here. "No," she said, making Celestia glance at her in surprise. "As much as it pains me to say this, her power is wholly her own." She shook her head again. "Such a waste of potential."
"So then... how did all of the ponies there have the same Cutie Mark?" Celestia asked.
Luna was once again growling and glaring at Starlight. "That would be because this stupid, foolish, MORON, decided that magically removing a pony's Cutie-Mark and storing them in glass jars, of all things, was a brilliant idea!" she roared. "You could have started a Blight, you foal!"
Celestia noticed that Starlight was trying to say something but no words were coming. "You silenced her?"
Luna nodded. "She was quite insistent that Cutie Marks were evil, and only ever caused friendships to wither and die. She believes no pony should have any kind of specialty to them, and nopony should be better than anyone else." She sniffed. "I'm convinced making her Tirek's next meal would straighten that attitude out."
Celestia sighed, rubbing the bridge of her nose. Right. Luna could get vindictive when angry. "Is she actually guilty of a crime, Luna?" she asked.
Luna stared at Celestia as if she had lost her head. "You're kidding. Right? I just told you she was tampering with Cutie Marks!"
"And what law could our courts use to persecute her?" Celestia added. "There is no law on Cutie Mark manipulation. Moral outrage, yes, but no actual law."
Luna bristled. "Well why not?!"
Celestia shrugged. "Until now, it was thought to be impossible without resorting to Necromantic magic, which is illegal. And yes," she interrupted Luna. "I do intend to have that added to the laws."
"Good, the sooner this idiot gets punished, the better I'll feel."
Celestia leveled a cool gaze on her sister. "She won't be punished," she stated.
Celestia hastened to continue when magic began flaring wildly around Luna. "Mainly for two reasons. One, there's a law forbidding the prosecution of someone who broke the law before it was actually a law. It's generally referred to as the Paradox Law. While you could probably argue that those who were involved in why it became a law should still be punished, the second reason will stop that."
Luna, slightly calmer than her near blowup a second ago, growled. "And that reason would be?"
"If we punish young Starlight here, then we must also punish Twilight. Remember how she ascended."
Luna's ears flipped back. "Oh," she said. "I had... not considered that."
Celestia set Starlight on the floor between her and Luna and removed the silencing spell. "As you can tell, Starlight Glimmer, you have just been discovered. Under normal circumstances we would have you punished quite severely for messing with Cutie Marks, but there are reasons we will not. Before anything else though, I'd like to know why you were removing Cutie Marks. Will you please tell me?"
Starlight shuffled her hooves slightly. She realized she had a chance to sell her philosophy to royalty, but by Luna's severe reaction (justly so, she told herself, if Cutie Marks really were the soul. That was magic no one wanted to mess with.) that wouldn't go over well. Instead, she decided to tell her story and hope it earned her some sympathy.
An hour later, Celestia and Luna were sitting next to each other thoughtfully as Starlight finished her tale.
"I see... I never would have guessed the discovery of a Cutie Mark could cause such heartache. Though... have you not tried to contact him?" Luna asked.
Starlight nodded. "Multiple times, Your Highness. But he never responded. I was also turned away from Princess Celestia's school whenever I tried to visit. The usual response was that only those of certain bearing could enter that school, and that commoners had no business distracting the students."
Fwoosh!
Starlight squeaked when Celestia's mane suddenly burst into flames and rage momentarily filled her eyes. She however calmed herself after a moment. "I'm okay. I'm cool. I'm in control." She muttered irritably, before stomping a hoof. "Argh! I thought I had finally stamped them out of my school!"
"Them?" Luna asked. Starlight also looked curious, but was too startled by the sudden pyrotechnics to really voice it.
"I'm not sure when, but at some point someone with... shall we say specific, views on magic became the Dean of the school. They passed all sorts of rules, chief among them being that only the rich and influential could attend the school. They tried to turn my school for learning magic into a school for nobles. Needless to say, I reacted badly when I found out, and promptly tried to clean house. I seem to have failed."
Celestia stood up. "Come with me, Starlight Glimmer. I wish to assure you personally that something like this will never happen again. We will also attempt to find your friend, because I can almost guarantee he did not ignore you. He probably never even received your letters."