Dark power surged through the room, making the burning lights on the half-melted candles flicker and wave. There were skulls inside pentagrams that made a ring on the carpet, which seemed to be made of some unidentifiable fuzzy hide. Thick, leathery tomes were scattered on the floor, as if, once taken off the shelves, they were not easily put back. And—

“Is that blood?” Twilight shrieked.

“Nope, it’s jelly!” Pinkie Pie scooped some off the wall with her hoof and slurped it up. “Mmm!”

“I don’t think this is an appropriate setting for writing a book, Pinkie!” Twilight hunched back against the wall, then regretted it. She peeled herself off and hoped Spike could get it out with a brush and shampoo.

Pinkie Pie looked around.

“Isn’t it?”

“No! This looks like a place for an occult summoning of some unspeakable terror!”

“Yeah, we’re writing an economics textbook.”

“That’s funny. Real funny. Can you clear up some of this mess? And turn on the lights? It’s so dim in here. What’s this carpet, anyway?”

“Flattened, stale cake gone bad. I just scraped off the moldy parts that were growing hair and patted them down over the floor.”

“Great.” Twilight sat herself on a chair carefully and tried to keep her hoofs off the floor. “Can we just get started?”

Pinkie Pie bounced over, making squelching noises on the carpet and knocking over a skull. “I’m so excited to be your Vice Chief Executive Writer for this economics textbook with real-world stuff in it!”

“Uh huh…so let’s…what is that?”

Pinkie Pie hefted the thick book onto the table with an audible thump and opened it. It smelled of old attics and was apparently the home of a family of spiders, who scurried away with bitter eyes, all eight of them.

“This is some old book I found in the Cake’s attic when I first moved in,” Pinkie Pie said. “I stopped reading it because it was talking to me—”

“Talking to you?”

“—but I thought it would be useful. It’s all about evil stuff. Hey, whatcha writing?”

Twilight took her pen off the page and looked at the first words of the Economicon.

Chapter One: Nightmare Moon

Light flashed outside the windows. A moment later, thunder rumbled.

Twilight looked up. “Weather’s supposed to be clear tonight.”

“Yeah, these things happen when you’re being eldritch,” Pinkie Pie said with an air of unconcern.

“Eldritch? We’re just writing a book!”

“A book about the great evils that occur when you mess with the dark laws of social reality.”

“Y-Yeah….” Twilight frowned at the words. As usual from Pinkie Pie, it was a weirdly apt description. “Anyway, lets get started. What kind of things should we write about?”

“What kinds of things do you want to write about?”

How your mind can melt in front of a parasprite, and sharpen in front of an Alicorn. A pain in your ribs can keep you conscious, talking, thinking, to distract from the throbbing. Sometimes you can’t make a good move, and you just have to go for a winning one instead.

“How’d we do it?” Twilight stared at the four words. “We should have died so many times.”

“Friendship is magic?” Pinkie Pie said with a shrug.

“I…I don’t think that’s right, Pinkie. Sometimes at night I realize in my head I don’t take responsibility for what happened. It was all Princess Celestia’s plan and the magic of the Bearers. I…I can’t even say I just kept going forward or anything like that, because I didn’t in the forest. No courage, no particular intelligence or skill…I really should be dead.”

“We got lucky! It’s a Pinkie thing.” She wriggled her nose, as if smelling a particularly strong whiff of randomness.

“I thought maybe somepony was guiding us, or some magical force, or maybe Nightmare Moon was lying when she said she didn’t set the dangers in the forest, so I read about them. I couldn’t find a single thing in the Everfree Forest that couldn’t have been beaten by one of you girls.”

“Golly.”

“All of them would have killed me.” Her eyes narrowed, skin crinkling around the edges. “Couldn’t find anything I could beat if I was being honest with myself.”

“You sure showed Nightmare Moon.”

“She could have killed me at any moment, and I was powerless without you all behind me. That was luck.”

“You shouldn’t—”

“I shouldn’t lie to myself. This isn’t a story, there’s no guarantee the bad girl will want to talk or torture instead of killing.

“I’ve been thinking. Economists don’t do anything. We can’t build bridges, or cure diseases, or invent things. But the world needs us. We…keep it spinning.”

“Spinning? We’d get dizzy!”

“It’s a phrase from an old book, Princess Celestia is fond of it…never mind,” Twilight sighed. “An economist isn’t a piece of the puzzle, she makes sure there's a picture on the box. That’s what this book has to be about. The picture on the box, the instruction manual, a little sack so you don’t lose all the pieces.”

“Then let’s start!”

Twilight picked up her pen. “Name…Nightmare Moon. Aliases…Mare in the Moon, Princess Luna, um—”

“Um?!”

“I’m not writing that, I’m just saying um. She had some other names, I think she said them at the festival. We can skip it for now. Um…strengths…pretty much everything other than mental stability and coherent goals. Weaknesses…her sister, sound monetary policy, the Elements of Equilibrium….”

“What about HD?”

“HD?”

“Says HD here.”

“What’s that mean?”

“Um…happy days?”

Twilight scribbled “Maybe, over a thousand years ago.”

“What’s her STR?”

“Stir? She’s not a cook, Pinkie.”

“She is a CON, though, right?”

Twilight shrugged and wrote “Con: yes.”

“Would you say she has spells and spell-like abilities?”

“Of course, every Unicorn does.”

“How about the ritual for summoning her?”

“I don’t know, and if I did, I wouldn’t publish it in a textbook!”

“Oh, oh! I want to try making one up!”

Twilight listened. After a minute she got up, found a rubbish bin, and began dry heaving into it.

“So…maybe run it past an editor first?” Pinkie Pie watched Twilight retch.

“Pinkie,” Twilight said when she could talk, the air smelling faintly of stomach acid, “fillies might read this! Adults might read this!”

“It’s a cake recipe. I just used a goat’s—”

Twilight retched into the bin again.

“—instead of cinnamon, and then instead of stirring you subcutaneously—”

Mercifully, the sound of Twilight’s stomach trying to escape through her esophagus once again drowned Pinkie Pie out.

Finally Twilight sagged on her rump and closed her eyes. “That’s not a real ritual, Pinkie, and I’m not writing a word of it down.”

“Don’t worry, I scribbled it down,” Pinkie Pie said cheerfully, “although it’s good that you say it’s not real, since if it was, just writing it down could probably summon a small part of the real demonic entity.”

Laughter echoed through the room.

“It’s not funny, Pinkie,” Twilight said.

“That wasn’t me!”

Twilight’s eyes shot wide open.

Ha ha ha ha…HA HA HA HA HA!

Twilight jumped to her hoofs. “What was that?”

Pinkie Pie looked around nervously, teeth chattering. “I don’t know!”

You called me…what plane is this, mortal stock?

“The fifth one,” Twilight said automatically. “Third door on your left from the interplanar warping point Pinkie what did you do?”

“Wrote down a cake recipe,” Pinkie Pie answered honestly.

Ha ha ha…the livestock is chatty on this plane. You have summoned but a pale shadow of my true self. What are your desires, Food That Talks? I shall grant but one wish to the one who called me.

“I want a pony,” Pinkie Pie almost said, before Twilight magically clasped her lips shut.

“Listen, you, get out of our plane,” Twilight said as threateningly as she could with the smell of her own acids wafting across her nose. “We’ll get the Elements of Equilibrium and banish you!”

Open the pages of this book…write more, fill it with blood, feed my power! Rip your hoofs and write THIS INSTANT!

Pinkie Pie worked her lips free. “But then you’d need a substitute for the vanilla. Sorry!” She let Twilight’s magic hold them shut again.

Twilight glared at her, then cast her eyes on the Economicon. She walked over to it.

Yes…you hear my voice. I sense power within you, such magic for mere livestock, it was you who summoned me, I can tell, and you want power. I can give it to you, and wealth, fame, admiration, anything you desire.

Twilight stood in front of the book. A faint black haze surrounded it.

“Offer me money.”

Yes…yes!

“Twilight, no!” Pinkie Pie screamed. “Mmph!”

“And power too.”

I can give you more power than has ever been seen under your world’s sun!

Twilight placed her hoof under the cover.

“I want my book back, you son of a cake recipe!”

She slammed it shut.

Mmph! Mmmmmph!

The book bucked like an angry bull. Twilight held it down.

“Bother this occult stuff!” Twilight shouted, struggling to keep the book closed. “Let’s do this outside, in the daylight, next time!”

Mmmmph! Mmmmmmph!

“We are burning this copy and starting over,” Twilight announced. She let go of Pinkie Pie’s lips. “Well?”

Pinkie Pie always saw the opportunity for profit. “I have some ovens in my bakery that get really hot.”

“No.”

“But—”

“Absolutely not.”

“O-kay,” Twilight said. “That’s the first chapter.”

Pinkie Pie hopping around the table, puffy hair bouncing. “Let’s publish! Publish!” A sound like streamers going off burst from…somewhere on her.

“I think we need more than one chapter.” A little bit of Pinkie Pie’s infectious enthusiasm wormed inside her. “But it’s pretty exciting to have part of it written, even if it might be a very long time before we get to the end.”

“Loyal readers might have the opportunity to win a free tee shirt,” Pinkie Pie said with a straight face.

“But probably not,” Twilight added.

“We’re going to learn some neat stuff.”

“Could be.”

“Things that will be unveiled for the first time ever. Exclusive economic content, right here.”

“Very possible.”

“ An adventure to a mysterious foreign land where they eat fried potatoes with cheese curds in gravy.”

“Okay, no spoilers.”

She looked at the filled pages of their new book.

Chapter One: Nightmare Moon

Nightmare Moon is taller, stronger and smarter than anything you have ever faced, unless you have had the misfortune to fight Princess Celestia. Her horn is sharper than steel. Her eyes are as cold as the night.

I won’t tell you to run if you see her, because I didn’t. I won’t tell you to be prepared, because you won’t be. She is stronger, faster, better in every way than you. You will be as prepared as she lets you be.

There is really only one way to defeat Nightmare Moon, and that is to never let her into your world in the first place. Sound monetary policy is her one weakness, because it never lets her become strong to begin with.

If that doesn’t happen, you will need the Elements of Equilibrium. Here is what you must do….

It was something, Twilight thought. It was a start.