The mare had eyes that saw in modals, and they gazed dispassionately at yet another despairing pony. It was damp and muddy, and the pony’s white coat was smudged with dirt. Two long cuts ran down the pony’s flank in angry red streaks.

“I can’t,” the pony whimpered to herself. “I cannot, will not, do this.”

The mare’s eyes looked left, then right. The world was bulging noticeably in her modal vision as a second world threatened to split at the marginal seam. It bore a striking resemblance to mitosis, and it was her job to cut the seam at the very moment of the split. Otherwise the universe would end.

“If I choose to fight him, my sister will be destroyed,” the pony was saying. Tears stained her cheeks. “If I do not, I will lose everything but her. He did this on purpose, I know it.”

Time was running out. It would happen soon.

The mare’s blade hummed in her hoofs. Now, now!

And the white pony’s head whipped around. She stared at the mare with hatred. “You skeleton! You mute! You’re the one responsible for all this!”

The mare swung her instrument in a full circle, and the worlds were separated, each spinning on their different path through the modal space.

The pony blinked. “Where did you go?” She looked around wildly. “Mare? Mare? Where are you?”

The mare had no eyelids to shut her the black void of her eyes, which glowed in the center with twin blue sparks, but she winced at the tearing pain where her heart would have been. “Goodbye,” she didn’t actually say, and walked off through space, time, and possibility.

It was hard making friends when you were the Ultimate Reality, the Inevitable, the Cost to their Opportunity. Ponies tended to get upset when they realized she existed, and by extension, that they were about to lose something forever. Most happily failed to notice her altogether, and when that was no longer tenable, they blamed it all on her. Some lasted longer than others, but no pony could resist forever the allure of just not having to choose.

Even though that meant losing everything. Ponies were funny like that.

It wasn’t like she wanted to make friends anyway. It just looked like fun, that’s all. Birthday parties. Holding hoofs. Laughing together. She had a whole list of all the things she'd seen friends do.

She didn’t care that another November 2 had gone by without anypony wishing her a happy birthday. She had even worn a party hat to remind them, just in case any of them wanted to wish her a happy birthday, she didn’t care, but hardly anypony could even see her, and those who could wished they couldn't.

On the rare occasions she had to do a Reaping, when Death was busy (he was soooo popular. Good for him. She didn’t care), the difference was painful. Ponies might not have wanted to die, but once they were dead, they were pretty accepting about the whole thing. Hello, is this it? End of the line, so to speak? I was expecting a pony with a scythe. Don’t know if you’ve noticed, but that’s a—

And then with a heavy swing of her shovel, which had a very sharp edge, they would disappear to…a birthday party, probably.

No pony ever said, “My word, I was terribly afraid of this whole choosing business, but once I did it, it’s not so bad! Er, which way to the Great Big Retirement Home In The Sky?”

It was all to do with modals, and a loss more permanent than death.

Sometimes, in her black moods, she considered the world from far above. She pictured herself as kneeling on the edge of a black hole, with a pulley, weight, and platform. She could pull things out, but only by lowering something in.

She thought about all the worlds she had consigned to the realm of Lost Beyond Lost.

She thought about what would have happened if she hadn’t.

She thought about it while wearing a purple dress with yellow stripes and bright pink polka dots. It was the only piece of fashion advice she had ever gotten, from a pony who had long since tired of her. It didn’t fit—she was too skinny, too boney. It made her look like a clown.

Clowns had lots of friends, didn’t they?

That wasn’t the reason she kept wearing it, she just liked how it was too long and made her trip when she walked.

So dressed like a clown and utterly alone, she did the thankless work of cutting worlds apart.

Until she wasn’t alone. Until there was a pony who thanked her, smiled at her, treated her like a f…a f….

Easy. Steady. Good thing she didn’t have a heart, or it’d be beating so fast you could hear it.

The first thing she noticed about Twilight was that Twilight noticed her.

“I like your dress. It’s really pretty.”

Fitting how the first words Twilight ever spoke to her were in a library. The mare hadn’t answered. She wasn’t much for conversation, and it wasn’t so strange to be noticed. It happened, not as often as it did for Mr. Popular, and it was usually fillies who did the noticing. They cried a bit and complained, and their parents would endeavor to convince them the mare didn’t exist, often, ironically, with a purchase. In time she would cease to be noticed. The filly could only see her now because she was choosing among mere books. When the choices became heavier, her eyes would dim.

“It’s okay if you don’t want to talk,” Twilight had said. “I must seem really weird to you, huh, all fleshy like this?” Her tongue was a little slower than her lips, giving the words a stretched quality. “You’re always around, but you never say anything. Is it because I look weird?”

The mare gazed at Twilight.

Seeing that she wasn’t going to answer, the filly turned back to the shelves, contemplating. “I want the best book here,” Twilight had said to herself. “Hm, hm….”

The mare was there that day in the library because she had to be to make the cut when the worlds separated. She didn’t have to be there for every decision, just like Super Scythe didn’t have to be there for every death. But she had to be there for this.

Death had hourglasses filled with sand.

She had a tiny little Earth spinning gently in the air beside her head.

The air crackled. The mare looked up sharply.

“Ow!”

Twilight stepped back. The tip of her purple horn was blackened, smoldering slightly. Even as it faded, Twilight’s eyes, and the mare’s, were drawn to the book that had fallen on the floor before her.

The words on the dark, worn cover burned with raw power.

FOUNDATIONS OF ECONOMIC ANALYSIS

The mare couldn’t hear the book speak, if it spoke at all. But everything Twilight did was etched into the tiny spinning world by the mare’s head, and Twilight heard something.

What she heard was probably this: Hello, Twilight Sparkle.

“Uh,” Twilight said, “hello.” They were in a library, so she didn’t shout or stumble away.

We have been waiting for you.

“Well…you are a book. I can’t imagine there’s much to do other than wait to be read.”

Twilight took the book to be checked out at the desk.

“I choose this one,” she announced to the old librarian. The mare, who felt she ought to say something, could think of nothing more appropriate than, “As you wish,” and she took her blade and slashed the worlds apart; one that came to be, and one that never was….

The mare was always with Twilight, but in another sense, she was usually busy. The next time she was attentively with Twilight was at the academy entrance exams.

Twilight smiled when she saw the mare walk in. The mare tripped over her dress and stumbled into a seat near the back

“Please face forward,” the examiner said severely. Twilight turned her head back, but noticed out of the corner of her eye the seat the mare chose. Another world was spinning gently by her head.

The mare watched Twilight with more than professional interest.

“Are you ready for the next test, Ms. Sparkle?” the examiner said. She was sitting at a desk behind a forbidding stack of papers, rather cowardly. “It covers the mathematical foundations you will need to succeed in your economics studies here.”

“Fine,” said Twilight, who knew all the mathematics in the world, so far as she knew. The library by her house was in fact much smaller than the Canterlot royal library,

Three-quarters of an hour later, exhausted, chastened, and more than a little humiliated, Twilight watched as the examiner wheeled away a chair that the filly had turned into a wheelbarrow in a failed bid at topology. The examiner was gone for a few minutes. She returned carrying a cup of coffee and dabbing at her brow with a cloth glowing in her trembling magic.

“That was—” she fell into her chair with a loud thump— “quite…yes…ahem.” She set the cup down, and dropped the cloth into it. “Oh, drat….”

“I didn’t fail, did I?” Twilight said nervously. She looked at the mare, then back to the examiner. “This isn’t it?”

The examiner set the cup aside with a nervous sigh and twice failed to straighten her crooked glasses with a shaking hoof. “Young filly, the test—it isn’t designed to be passed, you see…we just want to know what you can do…and how you react when there are things you cannot…ahem!”

“I passed?” Twilight said excitedly.

The examiner straightened up and took a moment to collect herself. “Before I give you your final results, there is one more test I must ask you to take.”

Her horn glowed again. The doors opened, and in floated a basket with a blanket, and in the blanket was a large spotted lavender egg.

“This is a test Princess Celestia has been giving to potential economists for two hundred and seventeen years,” the examiner said. “Everypony has failed it, and so will you most likely, but try anyway.”

“What do I have to do?”

“I don’t know.”

“What…what’s the test?”

The examiner shrugged.

She waited.

“That’s not a test,” Twilight said.

The examiner’s horn glowed. She sent the basket toward the door. It slammed shut, glowing lavender, before the basket could pass through.

Twilight released her magic. “That’s not a test.”

The examiner shot up. She glared at the impertinent filly. “Ms. Sparkle, that will be quite enough from you! The test is over, and—”

the bitter scent of crushed apple seeds

“…and…and….”

the bite of teeth on an old applewood pipe

Twilight Sparkle lifted into the air unsupported, surrounded by a magical glow. Her head was pulled back, pointing to the ceiling, showering the room in lavender sparkles bursting from her horn. White light shot from her eyes, bathing the room in something wild and free.

Magic, a great deal of it, had been released into the world. It was no business of the mare’s, and such things happened often enough in her, for lack of a better word, lifetime.

The egg cracked. It broke open. A head popped out, purple with green spikes, and immediately began to wail.

A flash of golden light lit the room. Princess Celestia surveyed the scene in an instant: the glowing filly, eyes burning white and lavender sparks erupting from her horn; a baby dragon, howling his distress at a rather rough introduction to the world; an examiner, coffee spilt over the table, gibbering against the wall.

Her horn glowed, and when it faded, so had Twilight’s.

“Hello…what is your name?” Princess Celestia said kindly.

Twilight had never seen Princess Celestia in person before. Her coat was whiter than an angel’s robes. Her crown was superior to any halo. She was as bigger than other ponies as a princess properly ought to be, and her mane rippled with the colors of the cosmos of creation.

“…Twilight Sparkle,” she said when she remembered to speak. “I mean, I am Twilight Sparkle.” She bowed.

Princess Celestia called the whining baby to her. A few gems materialized: The baby seized one and began to munch on it messily with a surprisingly loud crunching sound, the sound of rock crushing rock. His crying ceased at once.

“Dragons eat rocks,” she said. “And their teeth are quite strong, even from birth.” She looked at Twilight with interest. “You awoke this egg. I myself could not do it. I have waited a long time for this…for you.”

Twilight’s ears shot up and her tail went as stiff as a board. “I—I didn’t mean to! I mean, I didn’t—” she bowed— “your Princessship, I didn’t—” bow— “mean to…to cause any trouble, or…I didn’t know what I was doing!”

“I’m quite pleased, and yet not overly enthusiastic,” Princess Celestia said, smiling easily. “If a few millennia aren’t enough for a proper calibration, one might as well quit trying. And you don’t have to keep bowing. Once is enough.”

“Yes, Princess!” Twilight’s neck jerked down before seizing abruptly; her knees locked in panic mode as her brain tried to catch up with itself.

“Congratulations on your cutie mark,” Princess Celestia said.

Twilight spasmed, looked down at her flank where a light brilliant raspberry mark in the shape of a beaming star, surrounded by five smaller starbursts, now showed on her coat.

“I…I….”

“Yes?”

“I wanted a supply and demand graph!”

Princess Celestia laughed. After a stunned moment, so did Twilight, somewhat breathlessly.

The mare watched stonily. Even Twilight had forgotten her in the excitement. Princess Celestia had not seen her when she entered the room, nor could she see her now.

“Twilight Sparkle, would you like to come study economics with me in Canterlot?” Princess Celestia said. The baby dragon started greedily on another gem, filling the silence with his loud crunching.

The mare leaned forward, blade ready.

“Yes!” Twilight actually jumped, then hit the ground rather suddenly as her legs lunged for the earth in panicked embarrassment while her brain screamed at them for nearly ruining everything.

The mare sat back. That hadn’t been it.

“And,” Princess Celestia, “will you raise this dragon as your own? You don’t have to, but he seems to be yours.”

The mare’s blade leapt into her hoof. Twilight answered; the mare cut:

“YE

/

ES!”

“As you wish,” the mare murmured in a voice only she could hear, already getting up to leave.

“Now he needs a name,” Princess Celestia said as one world spun into nothingness, and another subsumed reality, “and his spikes will need to be trimmed, and as for food….”

The mare met Twilight again in the library of the Canterlot university. Twilight studied economics there with the most talented fillies in the world, none quite as talented as she. She hadn’t made any friends yet and hadn’t noticed this, just as she hadn’t noticed that she hadn’t spontaneously begun speaking Spanish.

“I saw you picking your nose, Minuette!” The voice carried through the aisles.

“Go away, Twinkleshine!”

“We saw you!”

“Shut up, Lemon Hearts!”

Twilight slammed her book shut. Somepony was interrupting her reading.

She noticed the mare as she headed over and smiled. “Hi. I like how you carry a shovel, it’s really unique. Are you here to help me? It’s fine if you just want to watch like normal.”

The mare could count on one hoof the number of ponies who smiled when they saw her. She counted one.

She followed Twilight through the aisle and into the area where two ponies were harassing a third, and a fourth was approaching from the shelf one over from Twilight’s.

“I picked my nose,” Twilight said, looking from the bullies to their victim and back. “All the noses were laid out on a table, and I picked this one.” Her speech was smooth now; no sign of her previous impediment remained.

“I lost my nose in a sneeze,” said the filly from the other shelf. Her hair was tied back in a slapdash way; it was red and purple and badly combed. “This one’s fake.”

Twilight grinned at her. “If you lost it in a sneeze, maybe you can go back and find it in a sneeze.”

They laughed, and Lemon Hearts snorted as well before remembering herself, and Twinkleshine was bright enough to understand the advantage of numbers. They backed off, and Minuette, now embarrassed, retreated to a corner with the first book she found big enough to obscure her face.

“I’m Moondancer,” said the Unicorn filly with the badly combed hair. “You’re funny.”

“I’m Twilight Sparkle. I saw you reading at the table. It looked pretty interesting. I would have asked you about it, only…reading.”

“I understand.”

The mare’s shovel was suddenly humming. She frowned. She couldn’t see what….

Twilight gestured toward the table she had been sitting at, where archipelagoes of table could be seen amidst an ocean of books. “Want to sit with me? We can talk about economics. Or just read next to each other.”

“Is reading next to each other like reading alone?”

“I don’t know,” Twilight said seriously. “I’ve never tried. But I think it’s more like

/

reading alone with a friend.”

“As you wish,” the mare said, a puzzled look on her face as Twilight and Moondancer went to enjoy each other’s company in a silence that was no longer cold, a stillness that held no fear.

The same acceptance Twilight had cast on the mare was freely offered to another. The mare found this disconcerting.

It was two years later. The mare stared at the cardboard box outside the door of Twilight’s house. Then she straightened her dress and raised her hoof to knock.

The colt in the box knocked first. The door opened.

“Hi!” Twilight smiled at the mare. Then she frowned. “Who’re you?”

The mare opened her mouth, but the colt in the box answered.

“I’m Shining Armor. I live in this box!”

“That’s neat.”

I don’t have a name, the mare didn’t say. But I’ve cared for you for a very long time.

“I’ll say.” Shining Armor shifted and leaned a leg on the edge of the box. “I was told I would meet somepony important here. Are your parents home? Do you live here?” His coat was a messy brown, though it was mostly dirt, and his mane badly needed to be scrubbed, combed, and quite possibly shaved off and incinerated.

“Yes, most ponies live in houses, not cardboard boxes.”

“Well, excuuuuse me, princess.” Shining Armor rolled his eyes. “I’m sorry for not knowing how you ponies do things in Canterlot. I’m from the Crystal Empire.”

“Wow! What’re you doing all the way down here?”

Shining Armor leaned back smugly, resting against a cardboard wall. “I go where I want. I’m a free pony. And one day I’m going to be the best economist in the world! That’s why I came to Canterlot, to study.”

“You can’t be the best economist in the world,” Twilight said hotly, disliking this smug colt at once. “Princess Celestia already is, and she’s not going anywhere.”

The colt made a fair impression of pointing a thumb at himself. “Not once this bad boy gets himself inside the library. I figure it’ll only take me a few years to start publishing in the top journals.”

“It—you—it takes years of hard work just to get a revise-and-resubmit in the Equestrian Economic Review!”

The colt smirked. “For everypony else, maybe. Check out how strong my instrumental variables are.” He flexed his legs, which did bulge impressively.

Twilight was open-mouthed. “That…that’s…do you even know what an instrumental variable is?”

“Do you?” He leaned forward. “Why, do you think you know something about economics, little filly?”

The sneer on Twilight’s face stretched wider. “Yes, I do, actually. I’m the highest-scoring filly in half a millennium in Princess Celestia’s select cohort.”

“Oh ho! So you’re an economist too! I wonder which one of us is better.”

“I don’t, because I know it’s me.”

“Ha! You’ve got an attitude, sis. I wonder if you can calculate the present value of an asset.”

“Present value? Ha! Can you prove Brouwer’s fixed-point theorem?”

“All right, sis, not bad,” he said grudgingly. “Maybe Princess Celestia knows a thing or two.”

“You’ve got a lot to learn. Come in—I’ve got juice. What’re you studying? I’m learning macroeconomics so I can help Princess Celestia with the One Bank someday.”

Shining Armor rocked inside his cardboard box, pushing it forward in jerks. “I study whatever’s available. I go with the flow, like a wave, you know? Also, I want to try surfing.”

Twilight giggled. “I go with the optimal decision rule. By the way, you really need a bath.”

“I hear baths have good acoustics. I want to work on my singing for my popular colt band where I'll be lead singer.”

Twilight laughed again. “You want to be an economist, not a singer!”

The mare stared, flabbergasted, as the door closed in her face. This colt was rude, arrogant, and disagreeable. Why was he invited inside? How had this crude interloper said more words to Twilight in a short meeting than the mare had in years of knowing her? How had he made her laugh?

Why did it hurt so much?

Worlds were coming apart, tugging at the seam on the margin, demanding her attention. Her shovel felt heavier than normal as she sliced away the worlds where Shining Armor did not become an older brother to Twilight.

The mare spent more and more time with Twilight as she grew into a young mare. The mare paid sharp attention now, seeking understanding. She studied the friends Twilight made, the tests she exceeded, and the cohort of strange fillies who grew around her and Princess Celestia, the little eddy and the great whirlpool.

“I don’t like those girls you study with,” Moondancer said to her one day. “Twinkleshine is awful, and Trixie is worse, and the rest of them are just bizarre. They’re cruel, Twilight, what they did to Lemon Hearts….”

“It was just a prank,” Twilight said uncomfortably. “We knew she was failing out, so we wanted to sort of see her out our own way. Something to remember us by.”

“I bumped into her the other day. She said she still has nightmares.”

“She wasn’t actually locked in the cage. If she had just been smart enough to realize—”

“It doesn’t matter! It’s wrong, it’s sick, and it makes me mad that you helped them. And I’m next.”

“You’re not,” Twilight said unconvincingly. Moondancer was as dedicated a reader as anypony Twilight knew, but she couldn’t keep up with her and Trixie and the rest, and that was a fact. There was Twilight, then the eight, and then, far below, was everypony else.

“It happened when Minuette failed out,” Moondancer insisted. “She wasn’t the same after, and my grades are borderline, everypony knows that. Don’t—it’s true.”

“No pony’s going to hurt you. I’ll make sure of that.”

“I don’t want you to hurt anypony!” Moondancer cried. “Trixie’s changed you. I miss the Twilight who would stand up to bullies in the library for a pony she had never met.”

Twilight leaned her neck to one side and scrunched her face. “We don’t hurt anypony. It’s just a prank….”

Twilight didn’t think she had done anything wrong. If anything, they had done Lemon Hearts a favor. But Moondancer was decent and funny and good, so she nodded and agreed that they might have gone too far. She didn’t say that Lemon Hearts had no business still being at the university; she couldn’t keep up and it was better for her to be out because she had quit than because she had failed, because it kept her in charge of herself. The cohort was shrinking every month now, and the loss was accelerating.

Moondancer wouldn’t last much longer. Twilight planned to shield her from Trixie and the others. But she couldn’t save her.

Later she asked the mare not to make the cut hurt too bad. The mare almost answered, and her answer was almost yes.

A very peculiar series of events began when Princess Cadance arrived in Canterlot to visit.

Princess Cadance ruled the Crystal Empire, a vast land to the north of Canterlot. Princess Celestia spared nothing on the fanfare and welcome. The guards were even more bumbling and ineffectual than usual, for Princess Cadance was rumored to be the most beautiful mare in the world, and that her beauty was a thousand times greater than any image could show.

They were wrong. It was not a thousand times greater. That estimate was low.

Twilight stood with the cohort, watching the formal reception in Canterlot. Moondancer was on her right side with her nose in a book as usual. Trixie was on her left, whispering something nasty about the sort of idiot stallions who became guards, as usual. She was, Twilight suspected, saying this in fact because Twilight's brother, Shining Armor, had become a guard, his peculiar way of getting closer to Princess Celestia. Recognized for his economics prowess (the Canterlot guards couldn't, and weren't expected to guard so much as piggy bank, let alone the One Bank), he had been promoted to captain.

The hapless stallions finally managed to seat Princess Cadance next to Princess Celestia without knocking anything else over. Then the guards performed their ceremonial spear-presenting…thing that involved a lot of stepping around very stiffly and twirling their spears and, Trixie snickered, looking like idiots, and then Princess Cadance pointed at the captain marching along the field and said something to Princess Celestia and the ceremony stopped.

Shining Armor was brought up to the princesses, looking strong and stoic, but Twilight knew he only ever looked serious when he was nervous. Then Princess Cadance smiled and for a moment even Twilight fell in love, even Moondancer looked up from her book, even Trixie could think of nothing nasty to say.

The mare was unmoved. Princess Cadance could not see her.

That was how Princess Cadance of the Crystal Empire and Shining Armor, Captain of the Canterlot Royal Guard, started dating.

Part 1: The Date

“So I guess you two are dating, huh,” Twilight said at lunch the next week with her older brother and Princess Cadance, whose macroeconomics textbook Twilight had read. She knew what sex was because the library. She also knew in a matter-of-fact way that it had nothing to do with her, and it had nothing to do with Shining Armor.

“That’s right!” Shining Armor’s hoof couldn’t seem to leave Princess Cadance’s. His voice was all wrong, his face shiny and a weird color. “Cadance and I are getting along really well.”

Princess Cadance smiled at her—not a heart-stopping smile, just a regular mind-blowing one. “I hope you don’t mind sharing Shiny with me. I really appreciate how mature you’re being. I know this isn’t easy.”

“Uh huh.” Twilight was mentally erasing the word Shiny from her vocabulary every time Princess Cadance introduced it. “Are you two in love?”

Shining Armor was grinning as broadly as Twilight had ever seen until he finally broke into laughter. It took him a while to stop. He looked happy. Weird happy.

Twilight had never seen him this way before.

“Are you two in true love?” Twilight said.

Princess Cadance’s smile was smaller, tinged with the wisdom of loss. An aging mouse eating nearby whose wife had passed away years ago took one look, keeled over, and died. “I think so. Why do you ask?”

“Only because I read this book called The Princess Bride—”

“Any good?”

“It’s blasphemous filth,” Twilight said calmly. “But I read it, and it’s about true love, and the kind of power it contains.”

“Love isn’t about power, Twilight,” Princess Cadance said gently.

Twilight hesitated. She hadn’t said it was.

“Twilight’s still at the age where colts have cooties,” Shining Armor said.

“I do not believe in cooties,” Twilight objected. “It happens to be an observable fact that colts care nothing for proper hygiene. Your room, for example—”

“Is very clean, and always has been,” Shining Armor said quickly.

“Spike passed out from the fumes.”

“Completely untrue,” Shining Armor said to Princess Cadance, who giggled. Something spread across Shining Armor’s face like butter. He wasn’t laughing. He wasn’t thinking. The look on his face….

Twilight shivered.

Nearby, a couple was bickering at a table.

“Go on, show her,” Shining Armor said. “Twily doesn’t know how amazing you are.”

“I know all about Princess Cadance’s research,” Twilight said. “It’s very pedantic.”

“It’s important to always be right,” Princess Cadance smiled softly. “That way you’re never wrong.”

“Show her!” Shining Armor said.

“Oh, all right.” Princess Cadance gave him an adoring look, then pointed her horn at the couple. It glowed, and something heart-shaped shot out almost too fast for Twilight to see.

“Well, I’m sick of your mother,” the stallion was saying. “If she doesn’t like my job, then she can go—”

He looked at her.

She looked at him.

“I love you.”

“I love you too.”

They kissed.

After a while, they were still kissing.

Twilight frowned. “How are they supposed to kiss if he’s standing behind her?”

“Maybe you should stop,” Shining Armor said hurriedly.

Cadance’s horn glowed again. The couple started, gave each other mortified looks. Faces bright red, they didn’t wait for a check, instead stuffing some bits into the waiter’s hoof as they hurried away.

Twilight made the connection.

Princess Cadance has mind control magic.

Then Twilight understood.

PRINCESS CADANCE HAS MIND CONTROL MAGIC!

Her mind raced ahead.

Why is a seven-hundred year-old Alicorn princess interested in dating a stallion with no special magic and who has to study economics by night with me because he works as a guard all day?

She isn’t.

Would a 700 year-old Alicorn princess be interested in the brightest young economics student Canterlot has seen in 500 years?

Maybe.

Twilight shoved away from the table, horn glowing.

“Twilight!” Shining Armor looked alarmed. “What’s wrong?”

“Stomachache,” Twilight said immediately. What kind of magic was Princess Cadance using? How could she prevent it?

She’s already used it on Shining Armor.

“I’ll make it better!” Princess Cadance said. Her horn glowed again. Twilight’s muscles seized, but she couldn’t even feel anything happen.

“That should clear up your stomachache." Princess Cadance smiled gently.

“Th-Thank you,” Twilight mumbled, her heart racing. Was this what it felt like to be mind controlled? She thought: I don’t like Princess Cadance. Did that mean she was free? Or that Princess Cadance, for whatever reason, was letting her think that thought?

Princess Cadance was looking at her.

She knows, Twilight realized. I might as well have told her.

Not a minute into her first battle, and she had already lost the war. Was that fair?

Princess Cadance yawned. “Now I’m tired” she pouted, leaning on Shining Armor’s shoulder. “You’ll carry me home, won’t you, Shiny?” She closed her eyes, face like a sleeping angel.

“Of course, my love,” said Shining Armor, who couldn’t seem to look away.

Princess Cadance opened one eye, looked at Twilight, and closed it again.

No need to say anything, Princess, Twilight thought viciously. I know what you’re saying: “I can make your brother do anything.” I won’t let you take him from me. This battle’s just beginning!

The mare watched as Twilight’s war against Princess Cadance began. She watched Twilight losing.

“I have something very important that I need to tell you,” Twilight said to Princess Celestia in her private office. “Princess Cadance is evil!”

“Please explain,” Princess Celestia said in a tone of voice that meant, “You know I have a country to run, don’t you?”

“She has mind control magic!” After that didn’t seen to have the intended effect, she added, “And I think she’s dating my older brother just to get to me and to you through me.”

“I see.”

Twilight paused. “Has she already used mind control on you?”

“No.”

“So…what should I do?”

“Try to get to know her, Twilight. She will be your sister-in-law, after all.”

“I….” Twilight turned red. “This isn’t about that!”

“No?” Princess Celestia turned to her papers in a final sort of way. “If you do lose a sibling, Twilight, it will not be in the way you expect. That is my warning to you.”

Princess Cadance’s stay in Canterlot lasted a lot longer than the original one week that had been announced. This was to do with her budding romance with Shining Armor, which the newspapers reported, speculated, and outright invented on with shameless glee. Every day Twilight’s desk was stuffed full of the worst ones until she changed the magical lock, and when it was brute-forced open and the newspapers piled in again she did the same to Trixie’s, threw the lock in there, and started carrying everything with her.

Twilight began her own letter campaign against Princess Cadance under a pseudonym. Strangely, her perfectly valid and well-documented concerns about a known emotions-manipulator dating the captain of Princess Celestia’s royal guard drew far less attention than the latest pictures of Princess Cadance and Shining Armor rubbing their snouts together. She doubled the number of statistics she used. It didn't help.

Princess Cadance was even invited to give a lecture on economics at the university. Twilight’s cohort, the dozen or so who remained of it, attended, Twilight under protest. When Princess Celestia pointed out that Twilight wasn’t required to attend, she huffily responded that somepony needed to keep an eye on the enemy.

She needn’t have worried about any sneaking around once inside the university walls. Princess Cadance’s ideas were as bright and solid as crystal. After the lecture the question-and-answer session went on into the night.

“She’s amazing,” said Twinkleshine, voicing the general, but not unanimous opinion as they gathered together in an empty study hall. “And very pretty, not that I’m into mares or anything.”

“I think she’s planning a war against Canterlot,” Twilight blurted.

They looked at her.

“Wow, all that from her dating your brother?” Trixie said. “Geez, Twilight, I knew you were paranoid, but I think that’s a new record.”

“It’s not the end of the world, Twilight,” said Twinkleshine. “Perhaps she’ll make you a duchess of the Crystal Empire. You might as well milk it for all it’s worth now in case they break up. Personally I’m surprised they’ve lasted this long.”

“You don’t understand,” Twilight said urgently. “I’ve been reading internal reports from the Crystal Empire—”

“How?” Moondancer asked.

Trixie laughed wickedly. “You’ve been reading Princess Cadance’s mail!”

Twilight turned a redder shade of purple. “I haven’t—there was good reason to believe—”

“All’s fair in love and war,” Trixie said faux-soothingly. “Remind us all which one this is for you?”

Twilight’s mouth open and closed. “I-I-I do not have a crush on my brother!”

“It’ll be okay,” Trixie said, oozing raw gloat with every word. “Even though you were raised side-by-side, technically he was adopted so this isn’t weird at all.”

They were laughing. Twilight closed her eyes, and, moments later opened them again in the safety of a familiar room. As the lavender sparks fell and faded around her, she wondered just what kind of pony took a crisis to be an opportunity for pointless cruelty, and decided that kind of pony was Trixie.

A few minutes later, Moondancer walked into the old room they had slept in together for years at the Canterlot Academy of Pony Sciences. Now Moondancer slept in it alone.

"Hey, 'Dancer," Twilight said, flopping onto a pile of books. Glancing about for a new title, she didn't notice the lack of a smile on Moondancer's face as the other filly swept books off her bed to make room to sit.

Moondancer swung her legs over the edge of the bed. “Hey.”

Twilight grabbed something interesting-looking with her horn and floated it over. “Guess who’s the worst?”

“…Trixie?”

“Only by default. Second guess?” Moondancer didn’t answer. Twilight barely waited as she began to scan a table in the back of the book. “Ding ding ding! It’s Princess ‘Notevil Goodpony’ herself!”

“Princess who?”

“It’s what my brother calls her.” Twilight turned now to the third chapter with a critical eye. “Something to do with somepony calling her Princess Evil Badpony around him.”

“Is that...helpful?”

“He’s under her mind control power,” Twilight said firmly. “Things can’t get worse. Maybe this way the part of him that’s still him won’t give up hope.”

“How do you know that part exists? Maybe it doesn’t work that way.”

Twilight hurled the book against the wall, its pages flapping like a damaged bird. Moondancer winced at the loud thudding sound and the possible damage to one of her books. She hadn’t realized how angry Twilight was. Somehow it had all seemed…silly. As if Princess Cadance and Shining Armor were just dating.

“I don’t know, to answer your question,” Twilight said acidly. Her horn seemed unusually pointed. “For all I know Princess Cadance just wiped his mind blank and replaced it with one of her own. I tried looking up what kind of spell she might be using, but it sounds like she was just born with this power. It’s odd, though.”

Moondancer tore her eyes away from the fallen book. “What?”

“I saw her use a spell with her horn like a Unicorn would. But everypony writes as though her face itself radiated the magic. She’s supposed to be so beautiful everypony falls in love with her on sight, blah blah blah. And no, I don’t know that she isn't just making me think that she cast a spell when it was really just her magic face. Or maybe she convinced them it was her magic face when really she was casting spells.”

Moondancer played her trump card. “Princess Celestia doesn’t seem worried.”

Twilight’s face twisted. “I-I think she might be…testing me. Maybe this is all a trap for Princess Cadance. Or maybe I’m useful bait.”

“That doesn’t sound very falsifiable.”

“We’re already dealing with a pony who makes every observation suspect. Falsifiability was thrown out the window the minute she started messing with ponies’ minds. If she doesn’t want to be the subject of unfalsifiable accusations, she ought to leave everypony’s brains alone.”

Moondancer didn’t answer, just looked at the book laying crumpled against the wall. The mare shifted, leaning on her shovel. Moondancer had not been able to see her since she was a young filly.

“I know she’s planning something,” Twilight said. A picture of she and Moondancer holding up their passing exams from the first year was framed on a small desk by the bed. “Look at the interest rates in the Crystal Empire. I gave you the data. Did you ever look at them?”

“Mmhmm….”

“I’m not crazy. Everypony says I’m crazy. In the newspapers—but could a crazy pony stay up for three nights in a row examining unusual interest rate movements? Well? Could they?!”

“Uh…I guess not,” Moondancer murmured. She usually entertained Twilight’s wild rants, but tonight she was strangely reticent.

“You think she’s planning something,” Twilight said.

She waited for the confirmation.

“Um,” Moondancer said. She turned her head away, looked for something on her desk. It seemed to take her a while to find it, pushing the same few pieces of paper back and forth. “I…I should show you this.”

Twilight took the offered paper.

“…A job offer,” Twilight said. Every cell in her body felt numb. “In the Crystal Empire.”

“I haven’t accepted,” Moondancer said quickly. “Only she said that she needed economists…and let’s be honest, I’m going to fail out soon here.”

“You need to study more,” Twilight said numbly. She couldn’t feel her horn, though its magical was visible around the paper. “I’ll help you.”

“You are helping me. I would have failed out last year if you weren’t helping me.”

The mare glanced at the spinning miniature world by her side.

“It seems like a really good opportunity,” Moondancer said unhappily.

“You’re my only friend.” It was strange. She was sitting down, so why was she dizzy?

“I…I suppose I could try to tough it out,” said a voice from Moondancer’s blurring face.

“I need you.”

“I…could stay….”

This is it, the mare thought with a swell of dread. The last time she will be able to see me.

Twilight closed her eyes. She opened them, and they were wet. “No. You’re going to fail out.” She couldn’t make out Moondancer’s face. She didn’t want to either, so she kept talking and didn’t wipe her eyes. “Your choices should be about you. I’m an economist. I won’t ask you to give that up.”

The mare almost missed the moment. Her swing was clumsy, but that had never mattered. “As you wish,” she mouthed, and this time she meant it.

She didn’t stay for the rest of the conversation. It didn’t last very long anyway.

The mare walked in a strange, giddy haze. She passed through walls, ponies, and the ground, paying no attention to what plane her hoofs found. Direction had no meaning when gravity was only a matter of politeness.

Lost in the strange glow of acceptance, the mare missed seventy-seven important choices. The worlds bunched up. Far away, conventionally speaking, as distance held no meaning to the mare, a zebra made an impossible discovery…..

When the mare reemerged into the world, she was standing by Twilight Sparkle.

“Shining Armor?” she said quietly, closing the door to his room behind her. “Can we talk?”

“Logically my response is affirmation, but by the same logic, my response could never be negation, so—”

She looked at him. The playful grin wavered, fell from his face.

“I don’t know how to tell you this….”

“You can tell me anything. Unless it’s something bad about Cadie!” He laughed.

Twilight flinched.

“Ah, Twily, I didn’t mean that.” He put a hoof around her shoulder and drew her near. “You know you can tell me anything. Actually, I’ve been meaning to talk to you about you and me and Cadie.”

Twilight squeezed her head through the space between his leg and body so she could see his face. “You’re breaking up with her?”

He chuckled. “No…but I want to apologize, and thank you. I know this has been a big change for you. That’s why, before I ask her, I want your permission to marry Princess Cadance.” Even as he said it a bizarre rosy color flooded his cheeks.

Twilight stared at him.

“I know this is a big shock,” he said carefully, still fighting down the blush, “and a really scary change, but I’m your big brother, and I’m not leaving you—”

“This isn’t about that!” Twilight screamed. She wrenched herself out of his grip. “I don’t care who you date! This has never been about that!”

He looked baffled. “Then why hasn’t my Twily been smiley?”

“BECAUSE SHE’S A MIND-CONTROLLING EMPRESS WHO WANTS TO TAKE OVER ALL OF EQUESTRIA, YOU DOLT!” Twilight took a deep breath. “She made you love her! With her mind control magic!”

He began to laugh. “Twily, Cadie is a pretty pony princess. She doesn’t need magic to make ponies love her.”

Twilight stumbled over whatever half-formed counterargument she was already preparing. She had forgotten that there could be a reason he liked her.

“Look, Twily!” Shining Armor pulled something sleek and glittery off the bed. “Shiny, your favorite! Cadance made these for us!”

“Us?” Twilight said. It was clothes. She didn’t think much of clothes on stallions.

“For the band, of course!” He put it on, swept back his blue mane, and struck a surfing pose. “Check out these moves!”

He began to gyrate his hips to some imaginary beat. For the sake of decency and the continued T rating of this story, she quickly stopped him. “I thought you wanted to be an economist!”

“Yeah, but I want to be in a band too. It’s my dream to be in the biggest colt band in all of Equestria!” He tried to shake his hips again despite Twilight’s magical hold.

“You never said that before!”

“Yes, I did. You just thought I was joking.”

“You were joking!”

“Because you got really upset when I said it seriously.”

Twilight faltered. Was it true? She couldn’t remember.

She can control your mind.

“Want to see a poster? She had them done up all glossy with FFBBB on the top, although the name still needs some work…I look the best, obviously….”

She grabbed his face and pulled it close to hers. She peered desperately into his wide eyes, searching for a sign of her brother, her real brother. “Are you in there, Shining Armor? Can you hear me? I swear I’ll find a way to save you!”

“Twily, it’s the real me, no mind control.”

“She’s controlling you, using you—”

“Prove it—”

That snap in his voice. Some of the analytical genius she had loved him for. Was it the real him? Was Princess Cadance letting it surface, to fool her? To torment her?

“Are you seriously going to marry her?” said somepony with Twilight’s voice.

A stallion wearing Shining Armor’s body answered, “Yes.”

“I don’t give you permission,” Twilight thought she said. It was hard to tell if she had spoken or not because the world was spinning on tilt. Why did that make it hard to hear herself? In her mind an endless stream can control your mind she can control your mind she can control your control your mind control your mind

and the two of them, snouts nuzzling, lips touching, the ghost in her brother that couldn’t work the face right, couldn’t make the voice sound like his….

Her legs crumpled. She had been wrong to think losing Moondancer would make her brave. It only made her hurt.

“If I lose you, I won’t have anypony,” she must have said, because Shining Armor was kneeling down beside her, saying,

“You’re not losing me…and Spike’s not going anywhere.”

“Touring the country…living in the Crystal Empire with her….”

“You’ll visit! I’ll visit! You can even come live with us, that’d be amazing!”

She didn’t think she was moving, even though the floor was tilting up higher and higher. Nothing was actually sliding, though the vertigo filled her head and made her weak.

“Princess Cadance?” she said in a quiet sob, her face hidden in her legs, covered by her mane. “Please…I don’t know why you’re doing this…please give me my brother back…please…at least let me say goodbye to the real him….”

His body holding hers didn’t warm her. “Twilight, I won’t marry her if you don’t want me to.”

Twilight didn’t answer for a long time. “If you’re the real you…it would hurt you…if I make the second-worst mistake….” She was trying to think in terms of probabilities and finding it incredibly difficult. She couldn’t begin to put an estimate on Princess Cadance’s plans, if she had plans.

There’s a way out, the mare thought desperately. Seeing Twilight like this…. The mare stepped out of the shadows, not that Shining Armor could see her regardless. Trying to make herself more obvious to Twilight, who was wrapped up in her own little world of hurt and confusion and fear, one threatening to tear away from all the others, There’s me! There’s me you can throw away!

Twilight didn’t even look at her.

“You can marry Princess Cadance,” she said, her body utterly still against his. “I won’t attend. You’re moving out…Princess Cadance will make arrangements. I’m…going to go…now.”

The triumphant slice! AS YOU WISH! screamed into the sky.

Twilight stumbled out in a fog, head hanging low like a weight was tied to her neck. Behind her the mare followed, crowing with strange emotions.

Yes! Yes! Yes! the mare thought savagely. Me! Me! I am all that you care about!

Twilight leaned against an elderly pony, who squawked in surprise. Twilight started and jumped away, mumbling an apology. She continued to drift, twice walking into ponies, and suddenly had to sit. It was hard to breathe, and she couldn’t see the grass in front of her eyes. It felt like when she had gotten the flu as a filly, only this time it was the vomiting that made her ill.

And above her, the mare exultant:

Make more friends! Find more brothers! Reject them all! Discard them like trash!

Twilight wasn’t crying. She was breaking.

Cast them out of your house! Throw them aside, demand unto them why they should have a place in your life! They are the worthless ones! ALWAYS LOOK AT ME! ALWAYS LOOK AT ME! ALWAYS LOOK AT ME!

From that moment on the mare always had some facet of her attention with Twilight. And so though the instance meant nothing to her, she was thus with Twilight on the week before Shining Armor and Princess Cadance’s wedding, when Twilight went to confront her brother’s fiancée.

Author's Notes:

If you think about it, if someone would rather have nothing than have you, they must dislike you a lot.

I expect this mare's had quite a lot of time to do quite a lot of thinking.