Welcome to the Hive, Twilight
Queen Chrysalis couldn't for the life of her think of the last time a pony had been in her castle, let alone walking free and healthy. The drones around her reared up when they saw her, bared their teeth, but a single glare from Chrysalis was enough to keep them in check. She understood their hunger, how hard it was for them to resist. It was dulled for her from centuries of age and self-control, but she felt it too.
Twilight brushed against her foreleg, breaking her train of thought as she once again felt the strange warmth of a pony touch her body. "Queen Chryssi, what's this castle called? Where is it in Equestria? I've never heard of it before, I don't think."
Chrysalis flashed a smile, she really was clueless about the situation. "That's because it isn't in Equestria, young one, but rather a neighbouring nation. Why do you think I was so shocked when I found out you'd travelled here from Canterlot of all places?"
Twilight turned to face her, eyes narrowed. "And you're sure Celly will be happy for me to study here, right?"
"Of course, Twilight." Chrysalis lied through her teeth, a trait quite common for her. "Me and Celestia go very far back, we've known each other since we were both young. We're close friends, in fact. I'll be sure to let her know you're here later today."
Of all the things she said, half-lies and forgotten truths, one made Twilight's eyes widen as she fell to her haunches in shock. "You and Celly were young once? You're as old as her?"
"Older than her, actually." And that was true. Chrysalis had barely been a century old when she met the young princess for the first time, still a pegasus then. "And of course, Twilight, all ponies—well, and changelings—were young once, even if they seem almost incomprehensibly aged now. How old do you think Princess Celestia is, Twilight?"
Twilight's eyes were locked on her, she was slowly biting her lip as she mulled over her answer to the question. "Well, she has to be at least a thousand years old, because that's when Nightmare Moon was banished, and maybe even older than that because they ruled together for a long time first... Two thousand?"
Chrysalis smirked at the guess, but chose to keep Twilight in the dark. "Older than you'll ever be able to comprehend, that's all I'll say. As for the name of the castle? Its name is Rahyshna, it means 'home'."
Twilight's eyes narrowed as she stood, peering up at Chrysalis. "Isn't that a bit of a silly name for a castle? Of course it's home, you live here."
A flash of indignation at the name of her castle being insulted, but Chrysalis soon remembered her need to treat this guest well and quelled it. Plus, she was finding it increasingly difficult to imagine harming something so small. "You misunderstand me, Twilight. This castle is not just my home, it is the home of the changeling race. They are born here, and they live here as a single unit, surviving and searching for prosperity."
"So you don't have cities, like Equestria does?"
"The hive is a network almost like a city, all of our citizens' base desires being cared for and everyone being able to work together to achieve their aims. We have no need for several, it would only be a waste of resources."
Twilight stopped trying to cast magic on the castle's walls long enough to listen. "But all the different cities in Equestria are really fascinating and beautiful, why wouldn't you want more?"
"Because changelings care about efficiency, not culture!" Chrysalis snapped, all too late realising the height of her volume.
Twilight took a step back, seemingly shaken, and it hit a note somewhere inside of Chrysalis, one that told her that she'd made a horrible mistake. "No, no, Twilight, I didn't mean to shout like that..." Noticing that the filly seemed trepidatious now, she hesitated before taking a step closer. "I just get quite passionate about my kingdom, that's all. You know what it is to wish to defend something, don't you?"
Twilight was still for a moment before shaking her head, and it gave Chrysalis an idea. Grinning evilly, she levitated Twilight's notebook away from her, lifting it just over her own head. "Hey, give it back!" Twilight protested, hopping and jumping in an attempt to swipe it from midair, then switching to her horn when each attempt failed.
A soft, powerful laugh, and Chrysalis relaxed her magical grip, allowing the notebook to fall into Twilight's outstretched hooves. "Well, now you do, at least."
"That wasn't fair!" Twilight pouted, nudging Chrysalis' side with a fetlock and marching ahead without her. Her movement was petulant, from the way she stomped her hooves to the shake of her tail.
And it made Chrysalis smile all the wider. "I'm sorry, Twilight, I was only attempting to illustrate my point. How about I make it up to you by showing you something really astounding that only changelings can do?"
Twilight didn't turn, but she did stop walking. "Hmm... yeah, okay, but only if it's really spectacular."
Chrysalis pushed her native magic through her body, feeling it change and reform as it became something else entirely, and soon enough, she was ready. "Alright, Twilight, turn around."
Twilight's ears pricked at the familiar voice, she already knew something was amiss before she'd even moved. After an uncertain moment, Twilight began to slowly pivot on the spot before curiosity took over, forcing her all the way in a single moment. There, she found her teacher, her mentor, Princess Celestia standing just where Chrysalis had been moments before.
"Celly?!" Twilight's smile could have split her face, she began to prance in place and skip forwards, all previous frustration with Chrysalis seemingly forgotten in the face of her favourite pony in the entire world.
"Hello, my dear." Chrysalis smiled from behind her guise, ready to flash back into her own body and startle Twilight, amaze her.
But she never got the chance. Twilight stopped dead, blinking rapidly and looking up at Chrysalis with bewilderment. "You're not Celly. There's no way, you can't be."
Chrysalis blinked as Celestia, feigning confusion. "And why is that, dear?"
Twilight vehemently shook her head. "Because the real Celly never calls me anything other than Twilight, ever. That's how it works, I'm Twilight and she's Celly. She'd never call me 'dear' or anything like that, I know that." A few seconds passed as Twilight considered the mystery concluded, but just as quickly, she tilted her head with a gasp. "Does that mean... are you Chryssi?!"
Another flash, this time for Twilight's eyes, and Chrysalis resumed her usual form, a chuckle rolling from her chest. "How astute of you, young one! You really are quite sharp, it's no wonder that Celestia holds you in such high esteem."
Twilight beamed at the praise, though Chrysalis wondered if she knew what half the words she had just said really meant. She was very capable for her age, definitely, but she was still only a child. A child that would come to love her more than she ever did Celestia, given time.
"So, could I ever learn to do something like that? To look like another pony?" Twilight's eyes were filled with wonder, if it was as if she'd just been given the codex to a vast level of knowledge that she'd never known existed, and now, somehow, she had to crack it open.
"There are spells made by ponies that allow you to assume the form of another, but what my race does is far different. We do not just 'look like' other beings, we become them. Their entire physiology inside and out becomes ours, the only thing that isn't changed is the mind. Pony illusion magic, however, has its limitations. I could show you how to look like another being, yes, but not how to become another entirely. That is an art reserved only for changelings."
"So I can look like anything?! A dragon, a butterfly?" Twilight was hopping around in place like crazy, bouncing around at speeds Chrysalis' eyes could barely keep up with, and raising a hoof did nothing to quell her.
"You could, yes, given time and practice. I assume you would like me to teach you?"
"Please!" Twilight rushed right up to her, staring up with those large, purple eyes that almost radiated affection and wonder. "I'd be really grateful, and I'd pay really good attention! I promise!"
"Well... I suppose I could attempt to teach you, but I'll have to test your aptitude first, make sure you're as gifted as I'm assuming." Chrysalis crouched down to her level, trying her best to put on a caring smile—it felt as real as it did false. "I'd very much like to help you become powerful, Twilight."
"Really?! You're so friendly, Queen Chryssi, I'm glad I found you!" She ran forwards to give Chrysalis another of those hugs she was so fond of, and against her better judgment, Chrysalis felt herself melting into it, if only for a moment. It was the novelty, she told herself, nothing more than that.
"And I am just as glad, young one." Softly pulling away, she righted herself, attempting to regain her usually intimidating stature despite Twilight's presence and the warmth that still clung to her. It felt forced. "Now, I'm going to show you around the castle, and find you somewhere to spend the night. How does that sound?"
"Can't I sleep in your bedroom?" Twilight asked with an innocent smile.
Chrysalis blanched at the idea. A pony, sharing the queen's royal abode? It had never been heard of, it was a mockery of her position. She answered with an emphatic 'no', but it didn't seem to shake Twilight from repeating the question with an added 'pleaseee?'.
"Again, that isn't an option."
Twilight hung her head, softly mumbling her thoughts. "The other changelings don't look like you," she said, glancing left and right to ensure that no one else heard her. Thankfully, they were alone. "They look a little mean, like they don't like me or something. I'd be a little scared if I was left all alone with them, Queen Chryssi."
...she made a good point. Leaving her with her subjects for any period of time unattended seemed like a bad idea, and she would have to ensure that each changeling in the hive knew soon enough that Twilight was off-limits. "Fine, you can have the room adjacent to mine, it's a spacious chamber that you can reach mine through, I've used it as a guest room in the past. Will that accommodate you, filly?"
Twilight hummed on it for a moment before springing up. "That sounds great! Oh, a big room all for me—can I run tests in it? Can I gather materials from your castle and study them in there?!"
Chrysalis cut her off by placing a hoof on her shoulder, the touch calming her before she could get too excited. "All in due time, Twilight. For now, I'd prefer if I could get you used to your new home, one step at a time."
"Okay!" Twilight nodded. "Race you to the next room!"
"If you think that I run for anypony, you are sorely—" Chrysalis gaped, Twilight was already running down the corridor. Growling, Chrysalis began to chase after her. "But you don't even know which way you're going!"
Who knew that training a child super weapon could be so exhausting? She caught up with Twilight, grabbing her to keep her still, and was just about to remind her why you don't go running off in places you don't know when she grabbed her back, tackling her to the side.
Chrysalis hadn't been expecting the contact, and was still off-balance from the short sprint, so the light push from the filly was enough to send them tumbling back together, Twilight laid atop her.
Then, she felt a strange vibration that she'd never once experienced, one she barely recognised. It was laughter. Not the laughter of victory or malice, but one of pure, unabashed happiness, and it was emanating from Twilight, coursing through her body and spreading to all around her. Chrysalis could feel it herself, and soon a giggle began to form in her own throat, coming out in dizzying, powerful waves, draining her breath but filling her with another, foreign sensation all the same.
They sat and laughed for a good while, neither of them moving, and then Twilight slipped off of Chrysalis' chest and landed on her haunches, and they both laughed some more.