Curiosity

by Brony2893


Our Other Halves

“—and I’ll be back in the morning to pick you up,” Twilight Sparkle said, hastily packing things into her overnight saddlebag. The normally tidy library had been turned inside out by the frantic unicorn.

“Aww come on, Twilight! I don’t like spending the night at Applejack’s and you know it,” Spike protested with crossed arms, displeased at the sudden change in his plans for a lazy Sunday in.

’Granny Smith’s snoring is too loud to sleep… and they all get up too early.’ He complained internally.

“I know, I’m sorry. It’s just that Rarity’s out of town so I—”

“And you can’t even tell me why!” The young dragon interrupted, earning a still glare from the violet unicorn.

Twilight sighed, pausing to look her assistant in the face. “Spike, I already told you… Princess Celestia sent a letter straight to me, requesting my presence at the castle as soon as possible.” She did feel a pang of guilt for the sudden disruption to their Sunday agenda, but a request from her mentor simply could not be ignored. “She didn’t say why, just that a chariot was coming for me.”

“I know, but…” Spike huffed and kicked his feet at the library floor. “Why can’t I go with you? I always go with you to Canterlot!”

“I was wondering that myself,” Twilight admitted.

“You don’t think you’re in trouble, do you?” The young dragon asked.

“I… don’t see why I would be. Haven’t left home much since we got back from Canterlot and the Crystal Empire last week.” The librarian shrugged, before checking her ‘need to leave right now’ checklist for the umpteenth time.

“Well, you owe me an afternoon off some day next week for this…”

“How about I just bring some gems back for you?” Twilight offered. She really didn’t want to, but in her mind it was a better tradeoff. “I know I’ve been working you to the bones with helping me research.”

Spike tapped his foot and bit his lip in thought, carefully weighing the options.

“Make it a nice emerald or quartz, and we have a deal.” He finally said before walking off downstairs, his fate having been reluctantly accepted.

Twilight breathed a sigh of relief. Looking through her bags, she noticed a rare sight; spare room. She paused at the nightstand by her bed. An idea formed as her violet eyes passed over a familiar book.

’Guess I can return this to the Canterlot archives while I’m there. Sure was nice of them to ship it out so quickly’

With a careful application of magic, the large, featureless tome was safely stored in her saddlebag. With a satisfied smile that both sides were evenly weighted, Twilight set off down the stairs. When she didn’t find Spike in either the main room, kitchen, or basement she figured he had already set off to Applejack’s for the night.

’I might get him two gems for being so mature today.’

With little else to do but wait, Twilight locked up the library and sat outside. Normally she’d have waited inside, but it was a nice, breezy day and she’d been neglecting fresh air for too long.

Just as she was losing herself in some random daydreams, she heard a flurry and turned just in time to see the chariot she was waiting for. Twilight thought it was strange Celestia would only send a single pegasus—decked out in purple armor to pick her up, but she couldn’t question the princess’s judgement. She thought he looked familiar at first, but it was difficult to tell with them all looking the same.

“Lady Sparkle? I’m here to take you to Canterlot. Please be seated and we can be on our way.” The stallion commanded in a firm, but polite voice. Twilight silently complied and got in, bracing herself for what she felt was going to be a very rushed trip.

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As she predicted, the chariot ride to Canterlot was faster than the usual escorts to the princesses. Twilight tried to judge the time based on the sun’s movement, but that wasn’t the easiest task in a chariot that felt like it was approaching the sound barrier.

Before long, Canterlot came into view and quickly changed from a speck in the distance into the full city. The pegasus slowed as they began their descent towards the castle. Twilight took the decrease in wind as a moment to try and get her mane into something resembling its normal shape. The massive castle came into view, but their course changed and they seemed to be going around the back. Odd, she thought, considering she was always let off at the entrance.

“Excuse me, where are you taking me?” Twilight called to the purple-armored guard.

“Princess Celestia’s personal balcony, ma’am.” He answered back.

’What?’

Twilight wanted to press him for further questions, but eventually settled that he wouldn’t—or couldn’t tell her exactly why. It didn’t take more than a few moments for the princess’s balcony to come into view. Unsurprisingly to the unicorn, Celestia was already outside, standing tall but motionless.

The chariot stopped smoothly in front of the railing. Twilight hurriedly jumped off and ran over to the solar goddess, unsure of how to greet her under the circumstances. Celestia regarded the guard before taking notice of her student, her expression surprisingly serious.

“Thank you, Artemis.”

“Your Highness.” He bowed before flying off out of their view.

Twilight felt a hint of anxiety, but pushed it aside and took a step closer to her mentor. “Princess Celestia? Is something wrong?”

The princess looked down at Twilight for the first time. She gave her signature smile, but it was as though there was no feeling behind it for once.

“Twilight Sparkle, it is so nice to see you.” She opened up her left wing for a quick hug, which the unicorn quickly accepted. “Thank you for coming on such short notice,” Princess Celestia said, releasing Twilight and taking a step back to talk.

“It’s alright, Princess. I wasn’t doing anything particularly important,” Twilight shrugged her shoulders. “But, why did you call me here? Why not the other girls, or Spike?” She asked, glad to have the short mystery solved.

Princess Celestia sighed the lightest of sighs, walking past her student to look over the edge of the balcony railing.

“I have reason to be concerned about your recent behavior. I understand you’ve been cooped up in your library since I saw you a week ago.”

“Yes, but how did you know that?” Twilight question as she took a seat next to the princess, who continued staring straight ahead. The princess’s strange behavior was beginning to give her an uneasy feeling in the pit of her stomach.

’Maybe Spike was right… I am in trouble.'

“Spike sent me a letter expressing his worry for how you’ve been acting. He was concerned when you—and I quote, ‘were obsessed with that weird book’. What was it you were studying all that time?” She looked down to her student, an expectant look on her face.

Twilight rubbed her forelegs together, breaking eye contact with the princess. “I have a feeling you already know.” She murmured, voice low.

“Please answer the question, Twilight Sparkle,” Princess Celestia said. It wasn’t a question, more of a command.

The unicorn looked up to meet her mentor’s eyes; they were serious and carried with them the sense of a parent scolding their child. Twilight felt very uneasy there, on the balcony before the princess. She’d never had Celestia be so short with her.

“I was studying…” Twilight sighed, seeing no way to stall or get out of this confrontation. “I was studying dark magic.” She answered. She slowly looked up to Celestia, whose face hadn’t changed.

“Why did you decide to study this?” Was all the princess asked. Her monotone speech didn’t help to ease the unicorn’s nerves.

“I—After saving the Crystal Empire, and seeing its effects, and the potential it had…” Twilight’s voice caught in her throat. "I wanted to know more about it; how it works, what it can do."

“Yes? What else?” Celestia didn’t take her eyes off her flustered, panicked student.

“I-I had this book express delivered to me,” Twilight used her magic to pull out the large tome she brought, holding it between the princess and herself. “The instructions were complex, but simple once I understood. Combined with what you showed me in the throne room… I was able to tap into it again.”

“Anything else?” Celestia asked.

Twilight was starting to feel less afraid, and more agitated at the princess’s short responses.

“Answer me this first, Princess,” Twilight looked the alicorn straight in the face, trying to appear strong when she was in fact, still rather unnerved. “Why are you being so short with me?”

The princess let her serious mask fall and sighed, closing her eyes and bowing her head for a few moments. “I’m trying to stop you from making a mistake born of curiosity,” Celestia lamented. The book—still in Twilight’s magical grasp, changed colors as Celestia easily took it from the less experienced unicorn.

"This book's contents are not only dangerous, but not entirely truthful either." She held it between them for a moment, settling it down behind her on the floor.

“What do you mean?” Twilight inquired, somewhat baffled. She’d never known a book from the archives to have any false information.

“Tell me, Twilight… what do you think dark magic is? From what the book has told you, and your own discoveries,” the alicorn asked with a leading voice, eyebrow raised.

Twilight blinked, caught off guard by the question. “It’s an alternate source of magical reserves inside all unicorns.” When the princess didn’t say anything, she took it as a cue to continue. “And it… could be safe if used in moderation?” Under the pressure of the princess’s stare, she couldn’t think of anything more.

“Twilight… I’m only going to ask you once to halt your research into dark magic,” Celestia momentarily dropped the act, and sat next to her student. “Dark magic isn’t just alternate magic sources… it changes unicorns, and alicorns too.”

“What do you mean? The book—”

"Isn't entirely truthful, as I said before," Celestia firmly interrupted. “It’s a dangerous item, that I’ve decided will be locked away now. For good.” She looked to the large tome with a scowl.

Twilight looked off to the side, a question plaguing her mind. “How did you know I had it?”

“All magical books checked out from the archives here are tracked, as are the ponies who borrow them.” The alicorn answered. “When it came back to me it wasn’t a regular scholar who held it, but my very own student, Twilight Sparkle… I knew I needed to act right away.”

“Why is this such a big deal? I still don’t get it…” Twilight pouted. The princess noticed this and wrapped a comforting wing around the unicorn, hugging her close.

“Because you have power, Twilight. You—unlike most unicorns, can freely access it. That is why.”

Twilight looked up to the alicorn, thoroughly confused. “But I’ll be careful, you know I—”

“Dark magic… it isn’t what it appears to be. It’s not just another source of free magic, it is you, Twilight.” The princess interrupted, earning another confused look from her student. “The use of dark magic, even in small doses, it can—and will eventually, change you.”

“Change me... how?” Twilight asked tentatively. The mare was rather frightened by this news, her heart racing as she recalled the hours of tapping into the powers.

“Do you remember what Discord did to your friends?”

“Yes.” Twilight nodded. ”He reversed their greatest traits, turning the into their opposites to put it bluntly,” She recalled that day with a wince. Watching her friends fight amongst themselves was torture, to say the least.

“That is correct. However, dark magic can be much, much worse.” The princess looked off to the horizon, looking at something her student couldn’t see. “Do you know why Luna, my sister, was transformed into Nightmare Moon?” She looked down to the unicorn.

“Of course. She wasn’t happy that ponies enjoyed the day more than her beautiful night,” Twilight recited as if she’d read it from a book, which she had. “But, why do you ask? Everypony knows that.”

“That is correct, but do you know where ’Nightmare Moon’ came from?” Celestia asked without pause.

“I—” Twilight hesitated. “I thought it was some sort of personality disorder. I… never asked Luna though, I figured it’d have been rude to bring that up.” The mare looked thoughtful for a moment. “Where did she come from then?”

“My sister’s mental health is sound. Nightmare Moon was dark magic,” Explained the princess, particularly blunt.

“What!?” Twilight blurted out, shaking her head. “But… that makes no sense!”

Celestia shook her head and drew her wing back. She moved to sit opposite her student, looking straight at her. “The dark magic inside Luna—inside all unicorns and alicorns—can and will change its host, overpowering them.”

Twilight blankly stared, stuck between her curiosity… and fear of what her time dabbling with the dark arts could do to her. Celestia however, continued speaking.

“Luna, just as you, was very intrigued by the power dark magic held, and found no inherent danger. But, while she was studying it… it grew within her like a parasite. It made its own consciousness, and poisoned my dear sister’s mind.”

“My sister most properly fit the element of Generosity back then; she was always giving herself to help ponies, and never envious of my day before that dark pool of magic tainted her mind,” Celestia scowled off to the side, thinking back on the subject.

Twilight thought it a good time to speak. “But, how could that happen? How didn’t either of you know?” Twilight instantly regretted her question, hoping Celestia didn’t take it as an insult for ignoring her sister.

“It was a smart entity, the dark taint. It hid when Luna and I were together… and was quick to overwhelm her. It turned her vain, and greedy. The being known as Nightmare Moon, the embodiment of her personal stores of dark magic had fully formed by the time I suspected something was strange about my sister…”

Twilight saw the pain in her mentor’s eyes as she told her tale. She took a tentative step and sidled up to the alicorn, hoping to comfort her in some small way. After a short few moments of silence, Twilight cleared her throat to ask a question.

“So… the dark magic in all unicorns, and alicorns, is a personal demon?”

“Yes,” Princess Celestia nodded. “It wants out, always, and will fool you into thinking it is safe. The more you use it, the more power it can exert over you, and eventually it becomes real.”

“I… had no idea,” Twilight bit her lip, looking down to her hooves. “Had I known… I’m so sorry, Princess.”

“It is alright, my little pony,” The alicorn sighed. “I’m just glad I knew before something terrible happened. If your dark magic got out of control… Twilight, there is something you need to see.”

Princess Celestia quickly stood, causing the unicorn leaning against her to stumble for a moment as she attempted to regain her balance.

“Princess?” Twilight looked up to the alicorn, who now stood on the opposite side of the balcony, regarding her with a serious expression.

“Twilight, I need to be completely sure you won’t give in to your curiosity. I have to show you the world as it may be, if you were consumed by your inner demon,” Celestia lit her horn and closed her eyes, exhaling a shaky breath.

Twilight opened her mouth to voice a question, but a sudden, blinding flash forced her to close her eyes, one hoof rising to shield her face. The mare’s violet eyes stung from the intense light, enough so that she needed to let them recover for a moment. As she opened them, several things became known rather quickly.

’Why is it so warm? And... Why do I smell smoke?’

As her eyes opened, a gasp left Twilight’s throat. She could scarcely believe what she was seeing.

The great fields and mountains she saw from the balcony were now burned away, and the mountains smoldered. Wisps of fire and smoke rose like great pillars in the distance, sweeping across the land and leaving scorch marks that seemed to scar the earth itself. The skies, if she could call them that, were endless swatches of orange.

Hot wind hit her face, and with it came the nauseating smell of something burning she could not place, though she suspected it was something that once lived.

”Twilight Sparkle.” A deep voice off to her side called. She nearly leapt out of her coat when she turned. There, standing where the princess was before was an alicorn she did not recognize.

Its coat was black as coal, the texture of which even resembling it. The pony’s mane and tail were made up of long flares of violent flames, whipping in the hot, dry winds. Its eyes seemed to be embers from the pits of Tartarus itself, and Twilight could feel as they focused on her.

”Twilight Sparkle.” The black, flaming alicorn said once more. Its voice rumbled the very air around them as it spoke, sending a shiver down the smaller mare’s spine. It was frightening, but not painful to her ears.

Then, it took a single step forward, while Twilight only took a half-step before tripping on her own hind legs. With pure, chilling fear running through her veins, she slowly stood back up, only to come face to face with the strange monstrosity of a pony.

“Who—who are you?” She choked out, barely audible. “Where did the princess go?!” Twilight leaned away, afraid the roaring flames of its mane would burn her.

”I am Celestia, Twilight.” The creature—supposedly Celestia—answered. It tilted its head slightly, blinking its fiery eyes. The unicorn looked unsure of whether to trust this strange pony, and it showed on her face. ”Twilight, do not be afraid. This is merely an illusion.” The black alicorn turned to present its Cutie Mark, which stood out as clear as day, unchanged against its dark body. Indeed, it was was exactly like Celestia’s.

“Celestia?” Twilight looked up to its eyes, finally seeing past the glare, and spotting the caring look hidden just underneath the surface. Only her mentor had those eyes, the kind that told her that everything would be alright.

”Yes,” Celestia nodded, her voice shaking the floor under their hooves. ”I needed to show you this...” She swept her hoof over the balcony, once more drawing Twilight’s attention to the hellish landscape where she remembered Ponyville, and several other, small towns to be, now a wasteland. ”This is what will become of Equestria, possibly the world, if your darkness were to escape.”

“I… I don’t understand, Princess,” Twilight turned. She had a hard time believing that this dark creature was Celestia, but the evidence was clear. “How could I do this? I’m just one pony.”

”Twilight? Do you remember when I said you had power,” The dark Celestia asked, receiving a quick nod from the unicorn. ”Your power is the element of Magic. Magic itself, the kind any unicorn can use.” Twilight’s confusion only increased, but she kept silent. ”Answer me this, my student… if Luna was generous and free of jealousy before, and turned into Nightmare Moon. What would happen to you?”

Twilight blinked. ’My opposite? I have a near-mastery over normal magic. So, my inner demon would—’

“Oh no…” Twilight’s epiphany was written across her face.

”Yes,” Celestia nodded, confirming the unicorn’s thoughts. ”The darkness incarnate of you would control all dark magic, and in much the way Discord changes ponies… you would draw out their evils. Every single pony would meet similar fates as Luna did with Nightmare Moon. Even I would be powerless to stop you.”

Twilight looked down to her hooves, letting the information sink in. The thought of her friends turning into monsters like Nightmare Moon was—

’Wait, my friends! They’d stop me!’

“But, the Elements of Harmony!” Twilight protested. “Wouldn’t they—”

”No.” The alicorn shook its head. As it did so, its horn lit with a magical fire and the world faded into white. Twilight covered her eyes once more. ”The elements are nothing without Magic to activate them.”

Then, another flash.

The peaceful sounds and smells of the garden below returned to the world. Twilight rubbed her eyes, waiting for them to adjust to the light once more.

“Princess Celestia?” She called, looking up. Right in front of her where the dark alicorn stood was the beautiful white alicorn she was familiar with.

“I’m sorry if that was a little intense, but I had to show you,” Celestia apologized, and it was clear by her expression she wasn’t proud of frightening her favorite student.

“But…” Twilight’s shoulders slacked. “Why couldn’t the other Elements stop me? They’re still powerful on their own, aren’t they?”

“Twilight, you are the Element of Magic. The other five Elements flow through you”. The alicorn reached out a hoof, raising Twilight to her own shaky hooves. “If you were overpowered by your own darkness… the other Elements would be powerless to stop you as you turned them as well.”

“Even you?” Twilight looked her teacher up and down, hardly believing she would ever be capable of something so sinister.

“Yes,” Celestia nodded. “Luna would be Nightmare Moon once more, and I would be a fellow harbinger of destruction.” She knelt alongside her student, who looked ready to burst into tears. A wing wrapped around the unicorn, pulling her close. She felt regret for showing Twilight that illusion, but the alicorn felt that there was no other way.

“Now you understand why I acted the way I did when you began your research,” Celestia finally said.

“Yeah. I’m… sorry I made you worry,” Twilight nuzzled into the soft coat beside her.

“It is alright my student. All I ask is you consult me next time before studying anything magical that you’re unsure of.”

“Heh, deal,” Twilight pulled from the alicorn’s embrace and stood awkwardly rubbing her forelegs. “I think I should… go. I should take a quick nap before heading back to Ponyville.”

“I imagine this has worn you out to a great deal,” Celestia said. “Please, head to your old room and rest before the journey back home. I can have a chariot take you home this evening, when you are ready.” She offered to the exhausted unicorn.

“No need, Princess,” Twilight waved her hoof. “I’ll just take a train. I… think the trip will be good to think things over.” She eyed the book, still sitting on the floor behind her mentor. “Yeah. It’d do me some good.”

Celestia noticed this. “It will be locked away, like it should have been all along.” She momentarily glared at the object in question.

“Well, I, um…” Twilight trailed off. She wasn’t normally awkward telling the alicorn goodbye, but today had been anything but ‘normal’. “I guess I’ll be going now.”

The princess gave a comforting smile as her student turned to leave. “Have a good rest, and ride home, Twilight.” She paused. “My offer still stands.”

“Thank you, Princess,” Twilight gave a quick bow before turning inside. It wouldn’t take her long to locate the room she grew up in, it was right down the hall from her mentor’s after all.

Celestia sighed, allowing her wings to droop ever so slightly. She went over to the railing to reflect, and hope the lesson got through to the purple unicorn she cared for so dearly. A faint noise caught her ears, twitching toward the direction of the disturbance.

“You can come out now.”

Luna materialized out from the shadows of the bedroom, having watched the entire ordeal. Walking outside, she noticed her older sibling’s troubled expression as she looked out on the horizon.

“You did not need to scare her like that, Celly.” The lunar alicorn chastised, an uncertain look on her face. “You enjoyed your little moment far too much.”

Celestia was silent for a few moments, staring off into the distance.“Yes. I did,” She finally answered in a slowly spoken, neutral tone. The alabaster princess grabbed the tome with her magic and walked off into the castle without another word, leaving her younger sibling to wonder just which statement she had acknowledged.