Half

Cozy Glow found her in the Archives of Canterlot Castle, muzzle buried in the pages of a book bound in real leather.

"A little light reading, princess?" she asked, smiling as Flurry Heart slammed the book shut, guilt clear on her expression.

"You're not supposed to be here," Flurry Heart accused, trying to go on the offensive. "This area is restricted."

"So it is," Cozy agreed. "And of course, as a princess, you have access to this wonderful trove of forbidden knowledge. Still, I wonder what your family would think about you sneaking into this place to read Grogar's works on Applied Necromancy."

"Strictly academic curiosity," Flurry said primly, turning her nose up at Cozy. "My family encourages me to seek out knowledge however I can, and it's important for a princess to understand the ways of her potential enemies."

"You have a point there," Cozy conceded, trotting up and taking a seat next to her on the dusty floor. "So, have you found anything interesting?"

"Plenty," Flurry replied shortly, glaring at Cozy.

"I see." Cozy's smile widened. "You should be careful with what you read in that one, by the way," she said, pointing at the discarded book. "Compare the summoning spell on page sixty-seven in it with page seventy-six in his second volume."

Still suspicious, Flurry nevertheless pulled the other volume from the shelves, flipping through both until she found the relevant pages. After a few minutes of reading, her eyes widened. "He interleaved the ritual between the two volumes, making each side look like the full ritual to anyone who tried to replicate his work without both halves."

"You're a smart one," Cozy said approvingly. "The last pony who tried to cast it didn't figure it out even after a decade of studying." She let out a shudder. "I found him hiding out in Froggy Bottom Bog— what was left of him, anyways."

Flurry shut the book with a loud thud. "Who are you?" she finally demanded, her whole body tensed and ready to fight.

Cozy pressed a hoof against her heart, offended. "Why, I never! Don't they teach ponies anything in schools these days?" She reached out her hoof in greeting. "Cozy Glow, at your service."

Flurry's eyes widened further at that name. "I've heard of you." Her voice came out barely above a whisper.

"You've met me, too, but you were probably a little too young to remember it," Cozy said to the mare who was approximately the same age as her.

"You're supposed to be reformed." Flurry shifted away from Cozy, looking increasingly uncertain.

"I only serve the princesses now," Cozy replied to the unspoken question. "All of them. Which is why I'm here to tell you that your plan will fail, little snowstorm."

Flurry tried to look impassive, but she couldn't hide the moment of shock that painted her face at Cozy's words. "Is this some kind of mind game you're trying to play to get me to confess to you?"

"Just some advice for whatever you may or may not be doing." Cozy reached out for one of the tomes, only to have Flurry slap her hoof away with unexpected strength. "Ouch! You alicorns really do need to be careful, you know. Not all of us are as durable as you or your guards."

"Sorry," Flurry muttered, cheeks reddening in embarrassment.

Cozy waved her off. "Don't worry about it. Anyways, about your plan for world domination..."

Flurry glared at her. "I don't have a plan for world domination."

"Uh-huh." Cozy rolled her eyes. "Okay, so about your plan to conquer Equestria, or— wait, actually, you're from the Crystal Empire, so maybe you just want to usurp your mom's throne?" She tapped a hoof against her chin in thought. "But the Empire's kinda tiny and you could do so much better, you know?"

"I don't want to conquer anything!" Flurry shouted with such vehemence that Cozy actually began to doubt her own assessment.

"You've been sneaking around Canterlot the whole time since your entourage arrived in the city, visiting several very questionable magic shops that supposedly deal with dark magic in secret," Cozy pointed out, almost trying to justify her conclusions to herself as much as to Flurry. "And now I find you reading Grogar in the Archives and looking guilty as a kirin in a burning barn."

"You've been following me?" Flurry asked, eyes narrowing.

"Just trying to be a good citizen and minimize collateral damage," Cozy replied. "So, if it's not dominion you're after, then what?"

For a few seconds, she saw Flurry wrestle with her own thoughts before the alicorn let out a loud sigh. "Well, this is embarrassing," she muttered, blushing even harder.

"Hey, I respect whatever it is you're trying to do," Cozy lied. She would never have been so indecisive. "And as someone who's been around the block, I can probably give you some advice. So, what do you want so much that you're willing to risk disappointing your parents like this?"

Flurry murmured something under her breath, too softly for Cozy to hear.

"Sorry, what?" Cozy asked, leaning in to hear better.

"I said I'm in love with somepony." This time, she could barely make out Flurry's words.

"Oh." At once, Cozy rearranged all the clues in her mind to fit this new narrative. "So who's the lucky mare? Or stallion?" When Flurry didn't speak further, Cozy nudged her with her shoulder. "C'mon, I promise to keep your secret. I'm really good at that, y'know?"

Another minute of internal debate, and then Flurry finally answered. "It's Luster Dawn."

Cozy froze, her own shock now clearly showing before she forcibly tamped it down. "Huh," she said noncommittally. "I guess you princesses like to aim high, and Twilight's student is probably about as high as you can get without it being incest."

Flurry stuck out her tongue at that. "Eww." She shook her head, as if to try to rid herself of some unwanted mental images. "And it's not like I like her because of her position."

Cozy raised an eyebrow. "So you'd still like her if she was some random student at CSGU?"

"Well, we might not have met if that was the case," Flurry allowed. "But if we had, then yes. I'm sure I would still have found her beautiful and smart and beautiful and witty and beautiful."

"How eloquent," Cozy commented dryly through gritted teeth.

"I'm a princess, not a poet," Flurry shot back. "I can't compose a song to win Luster's heart, but I know she loves magic, and if I can find something sufficiently captivating, then she’ll certainly love me back.”

“You seem very sure about that.” Cozy sidled in closer. "Twilight's student doesn't seem like the type to be easily impressed."

"I'm aware." Flurry turned away. "I... I'm not used to being the one trying to woo somepony."

Cozy smirked. "That's some rotten luck for you, huh? Almost anypony else would kill to have a princess fawning over them." She reached out to cup Flurry's chin, her voice dropping low and sultry. "I know I would."

Flurry pulled away, a sour look on her expression. "I'm not interested in you," she said pointedly. "Now if you'll excuse me, I need to continue my search for something that will secure the heart of the one who has captured mine."

"You know, there's another option..." Cozy grabbed another book from the shelves, emblazoned with a cutie mark that she knew Flurry would recognize. "I assume the daughter of Princess Cadance herself would know a thing or two about the types of magic that work on the heart itself."

Flurry sucked in a breath as she beheld the journal. "We don't talk about those spells," she said quietly.

"Your mom uses 'those spells' all the time, though," Cozy pointed out.

"She uses spells that remind ponies of the love they already have for each other," Flurry countered. "Luster barely knows who I am."

"It's mind magic no matter how hard you try to pretend it isn't." Cozy pushed the journal towards her. "Sombra's spells were based off of Princess Amore's. Which means you should be particularly well-suited to casting them. Or maybe being a good mage doesn’t actually run in the family.”

“It’s not a question of ability, but morality,” Flurry said, her eyes lingering on the journal. "I'm going to win Luster's heart without descending into evil."

"She says, while sneaking around and searching through books on dark magic." Cozy leaned in to whisper conspiratorially into Flurry's ear. "Let's face it, you're interested in this stuff, and you're not as good as the other princesses, are you?"

The young alicorn's look of shame was enough for Cozy to push on. "So what happens if you fail, huh?" she asked, dripping more poison into her mind. "What if your best isn't enough? Luster Dawn's the student of the Element of Magic— you think she hasn't seen a dark ritual before?"

"I—" Flurry faltered. "There has to be something here," she said desperately.

"And if there isn't?" Cozy asked again. "Or if you're wrong about the kind of magic she's into? Are you willing to take that risk for a mare you love? I thought princesses weren't supposed to be selfish, but I guess I was wrong."

That line confused Flurry. "What?"

"If you think you're what's best for her, then you should do everything you can to make sure you end up together, right?" Cozy affected a casual air as she spun out her fantasy. "Otherwise, she might end up with somepony else, sharing her heart's desires and pressing soft kisses against some other mare's neck as—"

"Silence!" The words weren't particularly loud, but Flurry let out an emotional burst of magical energy that flung Cozy back as she silenced the pegasus.

Cozy quickly righted herself in midair before flitting back towards Flurry. "Oh, sorry, didn't mean to hit a nerve," she lied. "I'll leave you alone now, princess." She turned to make her way towards the exit, before throwing out her final hook.

"You might find the spell on page thirty-five of that journal interesting, though. It lets you bind somepony's heart to yours, to instill total devotion. Which is how the two of you will end up anyways, right? So it's no big deal, when you really think about it— just a little more powerful than the love spells your mom normally casts.

She waved as she stepped around a corner and out of sight. "Anyways, bye, and good luck with Luster!"