Twilight Sparkle woke up in her Canterlot bed and thought nothing of it. Spike the baby dragon was in the kitchen, preparing crystal berry waffles (Spike liked the crystals, Twilight the berries). She ate noisily, as usual, and read the newspaper, as usual, gathering samples for her project, “Noise Masquerading as Signals: Risk, Uncertainty and Profit Over Breakfast.”(1) After eating, Twilight organized her files to digest and relax a bit before heading out.

Twilight lived in a house on a hill overlooking the busiest street in Canterlot, leading from the Bank to the stock exchange. The stock exchange was all noise, the screams of the newly destitute approximately 2.5 times louder than the joyous cries of the suddenly rich. The Bank was forbidden.

Doors of gold and silver that would have delayed even an Alicorn. Spells of holding, spells of confusion, of deliberation, spells that eat priors, that dismantle modus ponens, spells that rip the utility function out of a mind and replace it with rubber.

Traps. Pits of spikes, pits of acid, a maze of walls, walls that are monsters, empty spaces that are walls that are monsters that build walls around a pony’s heart. Doors that open you. Locks that pick hoofs apart. A slide that’s so much fun you forget what you were doing. Endless coupons.

And the sign. It reads, “Stay Out!!!”

For most ponies, this is enough.

Twilight did not work at the Bank. She worked at the castle of Princess Celestia.

The castle was layers. First was the layer of divine right, reverse-engineered from some ancient wet sword. Second was stone. Third, crystal, and over that, more stone. Then, magic—wards, hexes, becomings, begoings, and most precious, reminders.

Princess Celestia’s castle kept her schedule. Twilight was very glad the Princess didn’t seem to see the need for her castle to take notes or read documents. Otherwise….

Well, she would still have the seminars.

Economists came from around the world to present their research at the famous Canterlot seminars, held in a room not far from Celestia’s throne, the seat that was always cold. The journals were important, but it was at the seminars that the truly great research was separated from the merely necessary.(2) Citation count didn’t mean much if a presentation failed to gain traction at a seminar. Meanwhile, a sharp question could excuse months of absence from the journals.

Thus the seminars became vicious in accordance with the logic of the science of friendship. And it was Twilight Sparkle who ruled there, pulling herself a horn-tip above the other geniuses. Her throne was a seat at the very front and center, her scepter a pen jotting notes at a frightening speed, but not as frightening as when it wasn’t writing at all. And when she rose to speak….

More than one pony quit economics because of Twilight Sparkle.

Princess Celestia was not always present, possibly because when she joined them the levels of violence soared to unbearable heights. Even Twilight felt the hatred and desperation ripple up her backside like a wave of ozone before a raging storm, though nothing ever quite reached the tip of her horn.

When Princess Celestia did speak, which was not often, Twilight felt her heart being mauled. For the difference between Princess Celestia and Twilight Sparkle was like the difference between the sun and a desk lamp.

Twilight returned from the seminar still shaking and in a sour mood. She had made an incredibly stupid mistake, something basic out of Foundations, which would have infuriated her even in the privacy of her own study. To err, and to err so fundamentally at the seminar had consequences. Trixie had scored maybe a tenth of a point on that exchange. At least Princess Celestia had not attended.

Twilight kicked the door open. “Spike! Spike, where is Foundations?”

Spike was still scrubbing crystal berry juice off the ceiling.(3) “Hi, Twilight! How was the seminar?”

“Terrible, as usual,” Twilight said, trotting to the tall streams of shelves that flowed to a distant levee. “The presenter was a complete idiot—she flubbed the elementary proof of the Riewomann Theorem—and she smelled faintly of cheese. Oh, and Trixie—where is Foundations?”

Spike looked over at Twilight, who was perusing the ‘G’ section.

“Twilight, that’s—“

Twilight’s horn glowed, and so did the bookshelf. It tipped over. Books flooded like Hapi doing a cannonball into the river Nile.

“Twilight, you’re in the wrong—“

“Raaaaaah!”

Twilight had missed some things in her rage that were suddenly becoming terribly salient. The presence of her princess did much to sharpen her analytical mind.

“Twilight, I have a very important mission for you.”

“Hm,” Twilight said.

“You must oversee the NGDP Targeting Festival…”

“Hm.”

“…In Ponyville.”

“Hm.”

“You seem troubled, my apprentice.”

“Princess Celestia?”

“Yes, my faithful student?”

“I think…I think….”

“Yes?”

“I think I would like to visit the forest. Please, what is the Cerberus’s name?”

“Oh boy! Oh boy oh boy oh boy!”

“You must be Pinkie Pie.”

“You guessed my name! That makes us friends! Want some cake?”

“…Yes.”

“Howdy, Ms. Twilight Sparkle. My name is Applejack. We here at Sweet Apple Acres are happier than rattlesnakes at a birthday party for mice to see you—“

“Teach me how to bake an apple pie like you do.”

Applejack chuckled warmly. “That’s impossible. But I can teach you how to bake an apple pie like you will do after I’m done teaching you.”

“Give me a makeover,” Twilight said.

Rarity swooned.

“Stop that,” Twilight said. “Just…stop.”

“Never,” said Rainbow Dash.

“I have the greatest respect for cows,” Twilight said.

“I can tell you’re lying,” said Fluttershy.

Twilight walked off with Spike, grumbling.

Twilight strolled past the astonished Cerberus and into the forest. She didn’t navigate the maze, simply walked through it. It worked eventually, although she didn’t want to have to count on it a second time.

So there she was, in the clearing of Frankie Knight. The parasprite spoke. She ignored it. And kicked the statue over.

Then she began to run.

The Alicorn looked miserable as she walked across the stage, cast in shadow by the pollen.

“Where is your economist?” she demanded in a voice like a lonely volcano.

“Right here,” Twilight said, unplugging her nose. “AH-CHOO!”

(Thirty seconds later)

“My sister!” Princess Celestia shrieked. “You were supposed to use the Elements of Equilibrium!”

Twilight took a long drink of water. “Yeah, well, this was easier. Trust me.”

Twilight woke up in her Canterlot bed and thought, “Drat. I’m in a time loop.”

Spike was in the kitchen making crystal berry pancakes. Twilight magic-grabbed three and trotted out the door to the bookshop.

She came back ten minutes later.

“Get your things, Spike, we’re headed to Ponyville.”

“Huh?” He looked up. “But don’t you want me to finish these pancakes?”

Twilight sniffed.

“Yes, fine, get your things after breakfast. Obviously.”

“Where is your economist?” the hapless Alicorn demanded.

“Right here,” said Twilight Sparkle. “Hey, Spike, have a happy early birthday.”

She gave him the book.

“Atlas Shrugged?” Spike read. He opened it to the first page.

Twilight watched the giant green monster punch the black Alicorn until she flew out of sight. She came back, and Spike did it again.

“Well,” Twilight said as the battle raged, “This probably isn’t really efficient, but it was totally worth seeing. Give her a left, Spikey! A left!”

Twilight woke up in her Canterlot bed. “Fine, I’ll do it right,” she said.

She went downstairs. “Spike? How’re the pancakes coming along?”

“Really swell!” Spike said, wiping his scaly brow. Spike didn’t sweat, but having grown up around ponies his whole life, he had adopted certain habits. “The crystals are crunchy on the outside, juicy on the inside.”

“Great. Keep making them. I’m going to see Princess Celestia.”

“Where are the Elements of Equilibrium?”

“In the castle. But why do you—“

“Princess Luna thousand years jealousy anger you imprisoned me to Ponyville red herring must gather Elements create Bearers save world blah blah where’re the Elements?”

“…In the castle. Hold on, I’ll get them.”

“Oh boy! Oh boy oh boy—“

“Solve this maze.”

Pinkie Pie took the piece of paper and frowned at it.

“Part of the maze exists only in my imagination,” Twilight added.

“Oh, I got it!” Pinkie Pie said, drawing an imaginary line.

“One down,” Twilight said. “Have a crystal.”

“Howdy, Ms. Twilight Sparkle—“

“Yeah, yeah. Hey, Applejack, I want to tell you a secret, but you have to promise not to act on it. Deal?”

“…I promise.”

“Great. The secret is, if you adopted marginal cost pricing, you’ll make more money. At least try to produce on the lowest point of the long-run average cost curve, for Celestia’s sake.”

“That’s a terrible sacrifice you’re asking me to make, but I’ll keep my word—“

“Neat. Here’s a crystal. Gotta go.”

“Hey, Rarity, I feel real bad about myself. Cheer me up, would you?”

“Well, you look stunning, darling—“

“Gosh, I feel great! Thanks, Rarity, and hold onto this crystal for me.”

“Rainbow Dash?”

“I didn’t do it!”

“But I did. The cops are coming here! You have to save me even if it means risking your operation.”

Rainbow Dash didn’t hesitate. “You can hide in this cardboard box.”

“Awesome—crystal—bye.”

“Hey Fluttershy Spike’s kidnapping one of your animals while I steal all your money—“

Fluttershy tackled Twilight to the ground, kicking her with surprisingly strong feet.

“Ow—crystal—ow! Fluttershy—ow!”

The Alicorn with all the might of magic and none of friendship paced across the stage. “Where is your economist? Reveal her to me, my subjects!”

“Girls? Rainbow time!”

A rainbow beam blasted across the stage and ripped the darkness off the Alicorn’s coat. She collapsed, stunned.

“Great job, girls,” Twilight said. All the ponies beamed except Fluttershy, who was still sore about earlier.

Twilight woke up in her Canterlot bed.

“Oh, come on!”

The dreadfully boring apparition stalked across the stage. “Where is your glfmph?”

“Glfmph” is the sound an Alicorn makes when six thousand pounds of chewing gum is dropped on her.

The dark Alicorn skittered away from the stage. “Ah! Caltrops!”

The dark Alicorn danced across the stage, kicking helplessly. “No! Sticky pads!”

Twilight had lived a thousand lifetimes, which didn’t fit well into a body that hadn’t aged with it. The beard of life grew, but she never had to shave. Such was the paltry metaphor her shadowy existence amounted to.

The Princess did not call her every day. Sometimes the choices she made caused different things to happen. But there was no preventing the return of Nightmare Moon.

Today her princess called her, as she had done a thousand times before. Her legs, bidden by something beyond the electric impulses stemming from her mind, went.

Princess Celestia noted the look of dull existential nihilism on the face of her young apprentice, a look that had not been there yesterday.

“Twilight Sparkle, I have a very important mission for you,” she said.

“Sounds like something sister must be ahoof,” Twilight said. “I mean, sinister.”

Princess Celestia hesitated. Had that been…? “I need you to oversee the NGDP Targeting Festival…”

“In Ponyville? Sounds like a recession for my career.”

Yes, that was definitely it, Princess Celestia thought. Dramatic irony. Twilight Sparkle was in a time loop. One that had been going on for many loops, judging by how Twilight’s face looked like she had spent sleepless weeks caring for the incarnate foal of ennui.

It was nothing Princess Celestia hadn’t dealt with before. She knew exactly what to do.

“It is, in fact, a real problem,” Princess Celestia said. “Bad business is going on in Ponyville, and I need somepony to break the cycle.”

Now it was Twilight who hesitated. “Wait—that’s not….”

“What troubles you, my student?”

“I…I need to pack my things.”

“Sleep well tonight, Twilight Sparkle.”

That night Twilight had a nightmare. In her dream she was Queen of the Bank. In her dream she foresaw everything. In her dream she guided monetary policy so skillfully a millennium passed without incident.

Twilight’s vision was a world untroubled by demand shocks. That meant…

…The only kind of shock that could reduce output and increase unemployment was a…a…supply shock.

Twilight knew it. And that meant…

…Twilight Sparkle was a real business cycle theorist.

“No!”

Twilight awoke, breathing heavily, her eyes wide. For a moment she lay there, gasping, making sure she could still feel her four legs and tail, that she was still all there. Finally she turned her head and saw Pinkie Pie’s bright eyes gazing at her, reflected pink of the pathos at the center of every half-eaten pastry.

“Bad dream?”

Twilight nodded. It was hot under the blanket. She tried to shift and found she couldn’t budge for pony. Applejack was snoring gently squished against her side, and Rainbow Dash was tucked up around her head. Fluttershy was draped over most of her flank, and Rarity’s head weighed on Twilight’s legs, her horn poking uncomfortably into Twilight’s side.

“You okay?” Pinkie Pie whispered.

“I—I think so.”

“I thought making shadow prices on the wall was really fun,” Pinkie Pie said. “We should do this again sometime.”

Twilight sighed. “Yeah.”

“Night.”

“Night.”

Twilight closed her eyes.

Far away in Canterlot Castle Princess Celestia observed the side-times roll through the halls like smoke. They amused her, the ephemeral fractal phantoms and their fading incandescence dancing around her throne until they disappeared altogether. It was something to see, and she had seen many things in her millennia.

Time loops could be bothersome. Well that they were ended. Yet well that Twilight Sparkle should spend some time in her own brain made alien. It was the only brain she had.

1) It wasn’t a priority, but she liked to be able to work while she ate.

2) "There are marginal economists, and there are ponies like us," Twilight liked to quip. "The inframarginal inventors of the intellectual infrastructure." The seminars were essentially a board of directors meeting that judged and allocated scientific contracts, with Princess Celestia's opinion holding a majority share.

3) Twilight was a messy eater.