Just a quick heads-up. With three Sparkles in this story, things are going to get complicated pretty quick. So, after a little establishing at the start, Twilight Sparkle from Equestria Girls will be getting called Twi, Midnight Sparkle will get her own name, and Princess Twilight Sparkle will mostly be either Twilight or Princess Twilight.

Twilight Sparkle checked the things in her backpack. She was so excited, even just taking the backpack of things with her was an experiment all its own. "Sandwich, cheese and biscuit pack, the dress Rarity insisted I bring, notepad, pencil, pen…" Twilight reached into the pocket of her track pants and pulled out her phone. "… and my mobile."

"So you are going?" Sunset Shimmer stepped out from the other side of the damaged statue. Neither of the pair wore their typical school clothes. "How long are you planning to stay?" She walked around and touched her hand to the statue, feeling the soft warmth of Equestrian magic.

"This is an opportunity I can't afford to miss. I… I know that studying magic is my destiny. Ugh, that makes no sense. Destiny is all a load of hooey." Twilight zipped up her bag. "But I don't know what else to call it. It was looking at magic that let me find you, Sunset, and my friends. I can't help but want to search for more."

It was a desire Sunset knew all too well. "I will miss you, Twilight." She moved closer and pulled her friend into a hug. Squeezing, and getting a squeeze back, she was all too aware of how much alike they were.

"I am not going to be gone forever. I have a whole year off before college starts, but I don't intend to spend all of it in Equestria." It was so near to being a lie that Twilight felt uneasy saying it. She really wanted to learn about magic, and the best place to learn about Equestrian magic was at the source.

"If you need help, you know how to contact me." Sunset pulled back from the hug and pulled her backpack around in front of her, opened it, and revealed the special book. "Just write in Princess Twilight's one."

Twilight had a few seconds before she actually bounced in place like Pinkie Pie. "I can't believe the Princess of Magic is going to teach me!" She let out a fangirlish squeal. "I'm so excited!"

"She is the Princess of Friendship." Sunset didn't want to rain on her friend's parade too much, given how magic worked in Equestria, friendship and magic really were one and the same. "So when—"

Stumbling from the portal, Princess Twilight blinked and shook her head. "No matter how many times I go through that, it always leaves the taste of cheese in my mouth." She curled her face into a grimace. "Are you ready, Twilight?"

Twilight Sparkle still wasn't used to the sight of her duplicate. Sure the Princess wore her hair down, and didn't need glasses, but they really looked identical. "Probably easier if you just call me Twi, or things are going to get really mixed up." Twilight felt her cheeks color, and looked away in embarrassment.

"That's a good idea, some of my friends call me 'Twi' on occasion, but not all the time." Princess Twilight smiled, fighting off her distaste for the lingering cheese taste. "Shall we go? I have a whole study plan worked out. It will depend on how you look when you go through—"

The comment surprised Twi into blurting out and interrupting the Princess. "What do you mean? Won't I look like you?" She reached up and adjusted her glasses. "Since you look like me here, I mean."

"Well, my wings are a special thing, but I have heard you had those here, so I don't know what will happen." Princess Twilight gestured to the statue base that she had recently emerged from. "Shall we find out?"

The adventurous attitude made Twi's whole body tingle with excitement. Before she followed the Princess, she turned to Sunset. "Thank you, I will be back soon as I can!"

"I promise not to steal her for too long. On the plus side, we know time seems to run slower here. By my calculations she could spend three years in Equestria for each one that passes here." Princess Twilight grinned. "You can talk with the book, too."

Sunset reached forward and hugged both her friends. "I am going to miss both of you. If it weren't for me starting at college next month, I would join you." She meant it, too. For all she loved the human world, and all her friends in it, she would go back just to be with her closest friends. "Now go before I get sappy."

Both Twilights laughed at Sunset's tone, looked at each other and stepped into the stone. The vortex of magic grabbed them both. It seemed calm at first, but then the spinning started. Princess Twilight tried to yell out to relax, but as the rainbow magic pulled them apart and spun faster and faster, she couldn't get out a single articulate sound.

Princess Twilight stumbled—as she always did—as she exited the mirror. Four legs were a lot easier to recover on than two, however. Turning her head to the side (and shaking off the taste of intensified cheese), she held out a hoof to Twi. "Welcome to Equestria."

Twi looked up at the pony… unicorn… winged unicorn. Her legs weren't quite working, but experimentation was the order of the day. "P-P-Princess?" She turned her head to attempt to catch a glimpse at her own back, but spotted no wings.

"A unicorn. But don't worry, Twi, you have magic!" Twilight lifted a knee and struck a pose, shooting a spell up in celebration.

"And what about me?" The new voice tore the attention of Princess Twilight and Twi to the side where another pony lay. "What about… wait, I am free?"

"Who is…" Twilight gathered herself. "Who are you?" She looked at the pony that resembled herself. But there were differences: dark wings were folded on the mare's back, and her horn looked to have missing chunks out of it. But it was the familiar-stranger's eyes that captured Princess Twilight's focus. Circles of magic covered them, giving her an exotic look.

"Midnight Sparkle?" Twi tried to shuffle back from the dark alicorn. "No… No, it can't be! You aren't real! You were never real! I was—"

"SHUT UP!" Midnight struggled with her legs, putting them under her one at a time. When she was standing, she breathed in the magic pouring through the air around her. She closed her eyes, taking in the moment. "I was always real. You denied the magic inside you for so long, shunting it aside so much, that you made me."

"Your name is Midnight Sparkle?" Princess Twilight was confused. "I am not sure I understand, but I won't let you hurt my friend." She took the simple expedient of stepping between Twi and the dark alicorn. "I am sure we can—"

"No. No more games. No more letting everyone push me around, lock me away, and deny I even exist." Midnight spread her wings and drank the surrounding magic. "I exist now, more fully than I ever did." She stepped away from the mirror on shaky hooves. "And I demand my right to revenge!"

Twi stared up at Midnight in terror. All her fears, all her insecurities rushed in on her. "No… you don't exist, you don't exist, you don't ex—" Her mouth was suddenly full, and something was stretched around her head. Lifting a hoof up, she felt straps—some kind of bridle—was bound around her. At the end of the device, a gag was shoved into her mouth, silencing her cries to a soft whimper.

Midnight was in full control, she was unfettered magic, and now she was in the very source of magic. Stepping forward, she stared into the eyes of the Princess that stood between her and her ultimate revenge. "This doesn't concern you, move out of my way."

"Twilight! What's going on?" Applejack was the first to crash into the room. "We were setting up for the welcoming party and…" She trailed off, eyes widening at the three Sparkles in the room. Behind Applejack, four more ponies piled in, each expressing their shock with a gasp.

"This…" Princess Twilight looked to her friends, then back to the new alicorn. "This is Midnight Sparkle. It is a bit complicated, but it seems like she is going to be staying here too?" She raised an eyebrow at Midnight, the question offering a hoof to begin a possible friendship.

Turning her focus from the bridled focus of her anger, Midnight looked at the five new arrivals, then back to Princess Twilight. "You promised to teach her, to show her magic?" Twilight nodded to her. "Then teach me instead. She denied her power, denied me!" Midnight arched her wings and stretched.

"I would really enjoy teaching you both." Princess Twilight smiled, feeling things fit to the straight and narrow path that led to friendship. "Please remove that… thing... from her." She gestured to the bridle, that the Princess could tell was feeding off Twi's magic, using it to strengthen its grip on her.

"No." Midnight smiled. "Never." She saw the Princess' astonishment, noticed too how the other ponies seemed to adjust their stances. "Don't fight me."

"Like heck!" Rainbow Dash dropped to the ground from her hover, throwing a few shadow-punches into the air. "In case you didn't notice, Twilight is a princess. You have to do what a princess says, when it is the right thing to do."

Twi stared from Midnight to the others. She wanted to yell, to tell them Midnight Sparkle was too powerful, but she felt really strange, distracted… horny. A flash of heat sparked in her body as she merely thought the word, and she closed her eyes and moaned into the gag.

"Please, everypony calm down." Twilight Sparkle stood her ground. "Midnight, I am happy to teach you, but you can't treat ponies like this." She pointed to Twi, who to her shock was squirming, a hoof rubbing between her back legs. "What are you doing to her?" She couldn't look away, eyes trapped by the shock of the sight.

"Logical and focused, she was always a problem. I found ways to be a little more free; all I had to do was distract her clever mind. Masturbation was literally the happiest times in my life." Midnight smiled down at her former jailer. "Now she can deal with it constantly, she can learn what it was like to be trapped in your own head." She lifted her head and stared at Princess Twilight. "If you will excuse me, I will leave with my…" she looked to Twi, "… myself."

"Stop!" Twilight looked at Midnight. "Isn't there something we can do? Some way you could… let her go without," her ears twitched briefly to her friends, "fighting?" The moment she asked, Twilight felt Midnight's gaze change; she wasn't looking at a princess anymore, she was looking at food.

"That is an intriguing offer." Midnight looked at Twi, the lost mare's groans into her gag were pure music to her ears. "Very well. You were planning to have her stay two years, yes?" She waited for the Princess to nod. "Then for that duration you will be my special friends. You will do what I want, when I want, and how I want it." Midnight turned her head to look Twilight Sparkle right in the eyes. "And at the end I will relinquish all my claims on… her." She gestured to Twi with one wingtip.

"Twilight, just say the word and we will show this upstart what-for." Applejack narrowed her eyes on Midnight Sparkle. "No way in Tartarus Ah'm going to help you."

"Please, girls." Twilight looked desperately at her friends. "This—"

"That's just being mean, though." Pinkie bounced forward. "Human Twilight hasn't agreed to this, she needs to be let loose." She looked at Midnight. "The deal has to be to let her loose too, or I won't let Twilight promise! And you can't do anything wrong, or bad."

Midnight couldn't hold back a smile at the pink pony. Part of her mind imagined ways to bind Pinkie Pie up, the other half was wary of all the ponies. "I wouldn't dare do anything wrong." She smiled, pushing her chest forward a little. "Or bad. I promise." It rankled that her jailer was going to be free, it made her furious in fact, but now she would get to play with these ponies while she knew about it.

"You can't interfere with our jobs." Twilight drew the attention of the dark alicorn. "Or hurt any of us." Her mind raced looking for loopholes.

"No hurting that would leave a lasting impression." Midnight inclined her head. "But I have a lot of… stress… to work out. Be my relief, let me learn your magic and your world, and you can even send her back." She ruffled her wings and folded them back down.

"You have to Pinkie Promise." Pinkie stepped closer to Midnight Sparkle, showing not an ounce of fear. "Like this. Cross my heart and hope to fly, stick a cupcake in my eye." She poked her eye dutifully.

A warm rush of delight filled Midnight. "I will not leave harmful marks on you, I will not interfere in your work. I will own you for two years, and I will make you enjoy it. Cross my heart and hope to fly, stick a cupcake in my eye." She pressed her shod hoof to her eye carefully.

Princess Twilight looked to her close friends, then at her doppelganger—still writhing on the ground—and sighed. "I, Princess of Friendship Twilight Sparkle, do swear that I will submit to Midnight Sparkle for a period of two years, and that I will allow her to… to own me. I will protect my friends the moment she does anything bad." Twilight felt power in the air, a princess' promise was not made lightly. "Cross my heart and hope to fly, stick a cupcake in my eye."

Midnight stepped closer to the Princess. Leaning in, she inhaled the scent of the mare's mane and felt more alive than ever. "Mine…"

Frozen, staring at the wall, Twilight could feel the dominance of the other alicorn. "G-G-Girls…?"

"Ah ain't doing it." Applejack glared at Midnight Sparkle. "Ah'm sorry Sugarcube, but this just ain't on."

"Yeah Twi, we don't give in to the baddies, we kick their tails!" Rainbow Dash stood beside her friend.

"Go." Midnight Sparkle looked at the five ponies. "Go away then, and leave me to focus all my attention on your precious Princess. If I had six ponies to play with, you would surely get a break, little princess, but it seems like I will be spending two years dedicated to making you my perfect—"

"I swear." Pinkie Pie couldn't take her eyes off Twilight. "I will let you do those things. Cross my heart and hope to fly, stick a cupcake in my eye." She smiled at Twilight's look of relief. "But, on one condition."

Midnight was deeply curious, and turned to her third possession. "What is that condition?"

"I get to throw you the biggest party ever!" Pinkie grinned from ear to ear.

"Darlings, you can't be serious." Rarity looked up and down at Midnight Sparkle. "While I can certainly appreciate the dark and malevolent look, I just don't think you back it up."

Twilight Sparkle stared agape at Rarity. "R-Rarity, despite where she came from she is an alicorn. I might not completely like this situation, but she isn't really doing anything violent… Can you take that gear off Twi now?" She directed the last to Midnight, gesturing at the mare squirming on the floor.

"I did promise." Midnight hated to have to do it, but she couldn't hide the fact that the ponies before her intrigued her a lot more than Twi. "There," she gestured, unraveling the magic of the bridle, "but now—"

"No, not now." Twilight smiled. "The deal is so long as it doesn't affect our work." She smirked at Midnight. "The two ponies who have promised you both have duties until tonight. Pinkie needs to get back to her job at the Sugarcube Corner, and I have two new students to teach."

Midnight blinked a few times, looking at Twilight in consternation.

"Um…" Fluttershy stepped forward, successfully hiding from Midnight Sparkle by dint of having her mane covering most of her face. "But I really want to help Twilight." She looked at Princess Twilight, her fear fading into the usual background lull. "I will stand in for Twilight Sparkle, as she needs me. Cross my heart and hope to… to fly. Stick a cupcake in—" She froze as bright aquamarine magic lifted aside her mane.

"You would be Fluttershy. I remember you from when… when I managed to get free." Midnight brushed Fluttershy's mane a few times. "I want to see the face of the pony I will," she paused and leaned close to Fluttershy, pressed her lips to the trembling mare's ear, "put a collar around your neck and treat you like the pet you are. You love animals? I am going to make you one."

"Stickacupcakeinmyeye!" Fluttershy's eyes flew wide open and she yelled the ending to the Pinkie Promise without pausing. She panted, ears perked forward, unsure what to think let alone say. Looking at Princess Twilight, she begged her friend for help as her heart raced.

Seeing an odd addition to Fluttershy's normal terror, and having been unable to hear what Midnight said to her, Twilight stepped closer to the dark alicorn. "She has to go and take care of her friends. That is her job. Help your… your sister up, I have a lesson to teach." She stared at her other friends, the three who hadn't made the promise.

"Sister? I suppose she is. Come on little sister, we are going to learn magic." Midnight Sparkle reached out with her boundless power and levitated Twi up.

For her part, Twi had managed to stop rubbing herself, but she was in the cozy grip of the demon she had promised herself hadn't existed.

Author's Note

So I do this "Ask x" thing, x can be any pony within the story. You can ask them anything and ~~I~~ they will definitely hopefully reply. Keep the questions appropriate to the age-rating of the stories and of course, ~~I~~ they will answer the best question(s) in the author notes of the next chapter. The more votes a comment has the more likely I will get it to the right pony to answer, try and keep it to one answer per post! ~~I~~ They will pick one question per chapter.

Support me on Patreon or fuel my writing on Ko-Fi!

Join me on Discord. Warning, said chat may contain NSFW material and should be considered adult in nature.

Awesome ponies who are already helping to keep me in keyboards and rum:
A.P.O.N.I.
Boulder
Canary in the Coal Mine
Daremo
Dio-Drogynous
Ian
Javarod
Jeffh4
Mary Rowland
Mephia
Nils
Sirion123

And special thanks to the following, for careful eyes and friendly words:
Cross Lament
Jeffh4
Vutava