It had been a normal day for Twilight, for what passed as that in Ponyville. The school was closed that day, so she decided to spent it researching magical history in the map room, piles of books stacked high in all the chairs around the Cutie Map. She was gradually beginning to piece together a General Theory of Mid-Ponish Mana when a bright flash appeared in the center of the room, nearly knocking her off her seat.

She looked up, and her jaw went slack when she saw the source of the light: Princess Celestia, who had just teleported into the room. The Sun Princess looked down on her former pupil, slowly floating to the top of the table and setting down.

"Princess Celestia!" she cried. Twilight ran over, hugging her. Celestia returned the gesture, wrapping one long leg around Twilight.

When she pulled away, she noticed Celestia was frowning. A frown she recognized.

"Oh no," Twilight gasped. "What's wrong? Did something happen to the Elements? Who escaped Tartarus?!"

"No no," Celestia assured her, "Equestria isn't in danger this time. At least, I don't think it is."

"What do you mean?"

Celestia sighed. "Sister and I have encountered something very...odd, and I thought I would seek a second opinion, from you."

"Second opinion? What kind of second opinion?"

"One involving heavy mathematics. Finance, specifically."

Twilight tilted her head. "Finance? Is Equestria going bankrupt or something?"

"Oh, nothing like that. Quite the opposite. As sister and I were reviewing the country's income and expenses, we started noticing something incredibly strange."

"Strange how?"

"I'll explain when we return to Canterlot. Can I count on your help, Twilight?"

Celestia held out a hoof, smiling. In normal circumstances, Twilight's heart would be breaking records running up and down her stomach for Celestia to ask her help like this, but the way Celestia was acting...she said Equestria wasn't in danger, so what could it be?

Twilight grabbed Celestia's hoof, and her vision was consumed by brilliant yellow light. She felt her essence being flung across space and time, and in only a split second she felt her physical body return.

They had re-appeared in a well-lit room, somewhere in Canterlot Castle. Magical torches lined the walls, and underneath them were uniform, neat rows of shelves with incredibly thick books on them, each labeled with a date encompassing a whole Equestrian year.

And at the far end of the room, Twilight saw she wasn't alone. Luna, and most surprisingly, Moon Dancer were hunched over a table, closely scrutinizing papers with glasses as they argued with each other.

Celestia began to walk towards them, Twilight following close behind. As they approached, the subject of their argument became more clear.

"But there was an exemption that year! That makes their growth 2.94%!" Moon Dancer grumbled.

Luna pointed to one of the papers, scowling. "'Tis classified as a tithe! Ten percent absolute! We know about this tax, We wrote it!"

Celestia stepped forward, clearing her throat.

They both ceased their bickering, looking up to her and Twilight.

Twilight smiled at her friend. "Moon Dancer! What are you doing here?"

The scholar's expression softened. "Good to see you, Twilight. I'm here for the reason you're are, I suppose. We're trying to solve a mystery. The princesses here recruited me because of my extensive background in economics. Princess Luna here remembers all the old obscure bits of the tax code—"

"Modern finance is complete madness," Luna complained.

"—But between the three of us, we still haven't been able to figure this out."

Celestia looked down on Twilight with a small grin. "It was Moon Dancer that suggested we recruit you to help us."

Moon Dancer pushed up her glasses and sighed. "I know you're busy with the School of Friendship, but I can't think of any other pony to bring in for this. We've been at this for a while."

"I have not slept in three days," Luna added.

"Why?" Twilight asked.

She answered in a low voice and narrowed eyes. "This mystery shall not win."

Twilight walked over to the table while looking at the room around her. "Where are we, anyway?"

"Official Treasury Accounts," Celestia answered.

Twilight reached the table, scooping up one of the parchments and scanning it with a scrutinizing eye. "So what is this big mystery?"

Celestia walked over the table as well. "To make a long story short, we have reason to believe somepony in Equestria is very wealthy."

"So?"

"Very wealthy," Luna repeated. "Wealth nearly unknowable to even the most gold-starved wyrm."

"And we have no idea who it is!" Moon Dancer declared. "Somepony is wealthy enough to not only have their hooves in every single part of the economy, but wealthy enough to just straight-up cancel Equestria's own debts!"

Twilight did a double-take. "Wait, what?!"

Luna yawned. "This all started when sister and I one day found out that all of Equestria's debts, down to the last bit, had been paid off in full. When we began to investigate, all we could find out is that network of bank transactions that lay before us now had shifted into motion several weeks prior. This network is so labyrinthine, that the best we could deduce is that this currency was from a single source. We then sought Moon Dancer's help, and as best as we have discovered, all of this is from a single pony."

Moon Dancer continued. "Problem is, Princess Luna and Princess Celestia are already on a first-name basis with every rich pony in Equestria. If one of them was this absurdly loaded, they'd know."

"And therein lies the mystery," Celestia finished. "We'd like your help, Twilight, to figure out who this mysterious patron is. We'd like to thank them for their assistance in Equestria's finances."

Luna grunted as she picked up another paper. "And tax them, if necessary."

Twilight rubbed the back of her head. "Well, I'll take a crack at it."

There was an extra stool next to the desk, and she sat down on it, taking her place with the other two. "So, where do we start?"

Luna shuffled through the papers, bringing out a particularly long scroll. "I'm afraid you don't understand, Twilight Sparkle. It starts everywhere. This is simply a scroll where we've notated the best leads. Choose one of the items on the list, and help us solve this quandary."

Celestia took up her spot near the desk as well. Twilight's giddiness to do such a service to Equestria slowly dissolved into a hard, exhausting slog. The night pressed on, Luna finally collapsed from exhaustion, Moon Dancer stormed out of the room several times in frustration, and Celestia simply couldn't keep up with Twilight once she got going.

Dawn was breaking. Celestia had left to raise the sun, and when she returned, she came back to Luna still asleep and Moon Dancer staring at the scroll she'd been staring at for the last two hours, eyes completely glazed over. Twilight was quietly mumbling to herself, hoofing through papers as she read the contents to herself in a low murmur, trying to put the pieces together.

Celestia walked back up to the desk and took one of the scrolls, though it was an empty gesture. She was also exhausted by the endeavor and soon found her eyes growing heavy as she began to nod off. Right as she'd drifted to sleep, Twilight jumped up and slammed the table.

"I'VE GOT IT!"

Celestia and Luna jumped awake and Moon Dancer fell sideways, tumbling out of her chair. She pulled herself back up, adjusting her glasses.

"Bluh?!" was all she could ask.

"I've figured it out!" Twilight declared. She began to hoof through all the scrolls and documents, pulling them together. "All these documents point to the transactions coming from here!"

"Where is 'here'?" Luna groggily asked.

Twilight placed a hoof on one of the documents. "Here. Canterlot Countinghouse, Inc. Sounds like some kind of accounting firm. It's right here in the city."

Moon Dancer leaned in closer to the document. "Huh. Doesn't seem like much."

"I almost didn't catch it either. They did some really creative number games to hide themselves."

She looked up to Celestia. "So, I'm pretty sure this place has the answers we're looking for. We could go there right now!"

Celestia shook her head. "I'm afraid not. Luna and l have spent enough time as it is on this mystery. Why don't you and Moon Dancer go in our stead and report back? Besides, either of us appearing there might cause a fuss."

"Hm...I guess you're right. What do you think, Moon Dancer?"

Moon Dancer brought up one of the papers. "I think I need to know just how much money we're actually dealing with here. If it's the amount I'm guestimating right now, we're going to have to toss out about two centuries' worth of economics."

"Then it's settled!" Twilight announced. "We'll be back in a jiffy!"

She laid a hoof on Moon Dancer and teleported them both. They reappeared instantly in Canterlot's square, and Moon Dancer scrambled sideways in shock.

"Augh!" she screamed. "Warn me when you're going to do that!"

"Sorry. Anyway, it should be just down this road."

She began to walk out of the courtyard, with Moon Dancer following. She had the address memorized, so it was only a matter of navigating the mazelike structure of the Old Canterlot Quarter to find the place they were looking for.

After an hour of searching, they found it: Canterlot Countinghouse, Inc. It wasn't much to look at; a grubby, brown building that stood out in no way from the others around it, save a small silver plaque on the front door depicting some weighted scales. Twilight led the way, stepping inside first. A small bell rang on the door as she walked in with Moon Dancer behind her, and when their eyes adjusted, they beheld the interior.

A grey unicorn with half-moon glasses sat at a large desk in front of them, her eyes concentrated a scroll in front of her. Twilight could just barely make out a cutie mark of scales loaded with money on her flank, but by then the pony had looked up with a slightly annoyed frown.

"The pawn shop is down the street," she stated, waving them away, returning her gaze to the scroll.

Moon Dancer stepped forward. "Actually, we've been looking for this place. This is Canterlot Countinghouse, right?"

The pony looked up, lowering her glasses. "Interesting. What brings you here?"

"Well," Twilight answered, "I suppose you could say we're on official business by the princesses. They wanted to find out who paid off Equestria's debts, and I helped them trace it back to here. So...did you?"

The pony rolled her eyes. "An interesting accusation. Unfortunately, I cannot divulge even the slightest detail of our workings here."

"It's nothing...illegal, right?"

The pony's eyes turned to daggers. "No. We are the most ethical accounting firm in Equestria, probably the world. Everything is accounted for, by the numbers, by the law. Now please leave, I cannot risk you finding out about—"

The door suddenly flew open, and the bell was knocked off its fixture. Twilight and Moon Dancer turned to see Pinkie standing in the doorway, beaming. On her tail was Gummy, his toothless mouth firmly clamped down.

"Short Sell!" she shrilled, "I'm here for my monthly appointment!"

"Pinkie?!" Twilight gasped.

The earth pony noticed them. "Hi, Twilight! Hi Moon Dancer!"

Pinkie suddenly looked puzzled. "Wait, why are you guys here?"

"Oh no, not now," the grey pony moaned.

She stood up from her desk. "Please, Ms. Pie! Please return in a few minutes!"

"Why?"

"I don't need certain ponies finding out about confidential information!"

"What information, Short Sell? You mean all that money I have?"

Short Sell smacked her face, dragging her hoof down. "Yes, information like that. I'll escort these two outside and then we can discuss this in private."

"Pinkie?" Moon Dancer questioned. "Why are you here?"

Pinkie giggled. "Well, I have to come here once a month so I can keep track of all the—" Her face suddenly turned grim as she did a dead-on impersonation of Short Sell. "—staggering assets," and then returned to normal, "I have so here I am! What are you two doing here?"

Twilight blinked in disbelief. "We, uh, we're looking for somepony. Someone rich enough to pay off Equestria's debts."

Pinkie gave a dismissive shrug. "Oh yeah, I think I did that last month."

Short Sell kept her face buried in one hoof as Pinkie continued to spill the beans. "Shut up shut up shut up shut up shut up."

"Short Sell over there was talking about Equestria's debt for some reason, I don't know why I wasn't paying attention, and I got confused for how a country could have debt. And she explained that (and to be totally honest I didn't understand a word of it) but it sounded bad so I just told her to use some of my bits to get rid of it!"

Moon Dancer and Twilight replied in unison. "What."

"Yeah! So anyway, why are you guys here?"

"Pinkie!" Twilight yelled. "You're the one we're looking for?!"

"Looking for who now? Oh no, did I forget about a game of Long-Term Hide n' Seek?"

"No! The princesses wanted me to find out who paid off Equestria's debts, and we traced it back to here! You're the one who paid it off?!"

"...Yeah? Hey, what's wrong? Why's your mouth hanging open like that?"

Moon Dancer lifted Twilight's jaw up to close her mouth, and the Princess of Friendship shook her head. She ran forward, grabbing Pinkie.

"Pinkie, how rich are you?"

"Iunno. Short Sell and this building knows more about that than I do. Speaking of which, hi Short Sell!"

She waved over to the serious accountant, who simply gave a half-hearted, embarrassed wave back.

"Pinkie, would you...be willing to answer some questions? About your wealth? And this place?"

"No!" Short Sell cried.

"Sure!" Pinkie Pie trilled.

With a defeated sigh, Short Sell walked over. "Celestia help us. I suppose it was only a matter a time."

She pointed to Moon Dancer and Twilight. "You two will follow Ms. Pie and I to my office. You will not look at anything on the way there. You will only ask the questions Ms. Pie is willing to answer, and then you will leave, and not speak a word of this to anypony, even their majesties. Is that clear?"

They both nodded.

"Good. This way."

She turned and walked through the door behind the desk, Twilight and Moon Dancer following, and Pinkie bouncing.

Through the door, they saw the interior of the building was much like the exterior. Dull, brown, and a small group of very serious-looking ponies busily tapping away on keyboards or reviewing scrolls. A few of them noticed Pinkie, but quickly returned to their work.

They soon came to a large door at the back of the building. Short Sell opened it with her magic, letting the other three inside a room filled with papers, projectors, and pull-down screens before shutting and locking it behind them. She walked up to the big desk in the center of the room, then sat down.

"Alright," she said, "first thing's first. Ms. Pie, do you consent to these two being present during your consultation?"

"Sure!"

"I see," she mumbled, signing a paper on her desk. "Well then, Ms. Pie, I suppose if you truly do not mind, we'll proceed with your standard monthly briefing on your finances."

She smacked a large projector on her desk and it fired to life, light pouring out of the lens in front. She walked over to one of the walls, pulling down a large screen. From the projector, Twilight could see it displayed all kinds of financial data that even she barely understood, but they all pointed towards the same thing: big money.

"As you can see, Ms. Pie, your portfolio has increased in value, as usual. Your holdings in the Dragonlands remain steady, and your investments in Equestrian colonial efforts have, I am pleased to report, paid off in triplicate. Everything else has seen respectable gains."

"Wait," Twilight interrupted. "Dragonlands? Colonial efforts? Pinkie, what is this?"

She laughed. "It's all my stuff! I'm not really sure what that stuff is, though."

"Pinkie. When did you get this wealthy? And how wealthy are you?"

Pinkie tapped her chin in thought. "Well, I guess it all started when I was pretty young. I'd just moved to Ponyville, and was taking a trip to Canterlot when I accidentally wandered in here. Then I used the bits I had on me to enter something called the Stock Market."

"How?"

"Beats me, I thought I was buying a train ticket. Anyway, I get a letter from the office saying the thing I invested in was worth more, which means I had more bits, which I could use to invest in more stuff! So I came back, picked more companies, got more bits, and uh, yeah. Kinds plays out from there. Eventually I had more money than I knew what to do with, so Short Sell offered to take care of it for me. And I'm glad, too! Those were some really big numbers!"

"Ms. Pie is our most treasured client," Short Sell stated.

Moon Dancer looked at Pinkie skeptically. "So...how do you know which companies to invest in?"

"I dunno. I just pick at random."

"At random?!"

"Well, not always. Sometimes, if the choice is really tough, I ask Gummy!"

She petted the alligator on the tip of her tail. "Who's a little tycoon? You are!"

"But, that's not the only thing. Sometimes I do currency exchanges, bank takeovers, buyouts, colonial ventures, all that. But the result's always the same!"

Twilight stepped in. "Okay, second question. How much money do you actually have?"

Pinkie frowned. "Uh oh. You asked The Question."

"The Question?"

"Short Sell doesn't like it when I ask The Question. Says it wastes too much good paper."

"Huh?"

Pinkie turned to Short Sell. "Hey, I know you don't like it, but could I see how much I have right now?"

The unicorn sighed, hopping down from her desk. She walked over to the door, unlocked it, and peeked her head outside. Sucking in a gulp of air, she yelled to the entire room.

"NET WORTH!"

The other employees sprang up, several of them also calling out "NET WORTH!" before scrambling around the room. The dreary atmosphere of the room instantly evaporated, ponies running every which-way as they began to hurriedly scan scrolls, count bits, and even pull down an entire printing press from the ceiling on a pulley system.

After several minutes of yelling and the printing press going full tilt, it finally spat out a series of pages that were quickly stuffed into a thick folder by one of the staff. The printing press was hoisted back up to the ceiling and every pony suddenly returned to their workstations, the room quickly becoming quiet and professional once more.

The last active staff walked over, giving the folder to Short Sell standing at the door. She thanked him, then shut the door, walking back to her desk.

She opened the folder. "Ms. Pie, are you absolutely sure you're fine with non-clients viewing your finances?"

"Yep!"

Short Sell rolled her eyes. "Very well. Princess Sparkle, Ms. Dancer, you may view Ms. Pie's net worth."

She lifted to the folder over to them. Twilight took the folder from Short Sell's magical aura, levitating the folder in front of them as she reviewed the papers inside. Pinkie looked over their shoulders.

"I—" Twilight stammered, flipping one of the pages. "This is...you could buy every plot of land in Equestria ten times over!"

"Yep!"

Moon Dancer was also impressed. "She could buy out every bank, empty their vaults, and fill them back up again."

"Uh-huh!"

"Pinkie!" Twilight snapped, "Do you not know what you have here?!"

"...Stuff?"

"Stuff for what?"

"Wealth?"

"Do you think just amassing wealth is a game? What kind of game do you think this is?!"

"I dunno, but I'm pretty sure I'm winning."

Twilight hastily plopped the folder back on the desk, and grabbed Pinkie by her shoulders. "Pinkie. If those numbers are right, you are the richest person to ever live. Ever. No dragon has, or ever will have, as much wealth as you do. And you don't even know what to do with it?!"

Pinkie arched a brow. "What am I supposed to do with it? I thought the rules were I could only invest in stuff and make the big number go up."

"Anything! Solve poverty! Unlimited party supplies! Keep the Sugarcube Corner in business forever!"

"But I think that's cheating."

Twilight sunk back into her chair. "We're getting nowhere. Pinkie, do you mind if I tell Celestia and Luna about this?"

"I dunno. Short Sell said you wouldn't tell anypony else. She gets really mad at me whenever I say something. Maybe until next month?"

"I—fine. C'mon Moon Dancer, we gotta get back to Canterlot."

"Don't tell the princesses, though!"

"We won't. We just need to...discuss this."

Twilight jumped down from their seats and walked out the door. When they had been gone for a few moments, Pinkie turned back to Short Sell.

"So, I think I want to invest 25% in every single cake shop in Manehattan, hat factories, war bonds, Orihalcum mining, and dump the rest on whatever business is at these random coordinates I made up."

She slid a dirty napkin onto Short Sell's desk. The unicorn reviewed the chicken scratch it for a moment before tucking it under the pile of papers.

"For the orihalcum mining. Should I also invest in orihalcum refining?"

Pinkie pondered the question for a moment. "Hmmm, that's a toughie."

She turned to Gummy, still clinging to her tail. "What do you think, Gummy?"

The alligator made a raspy grunt.

Turning back to Short Sell, she nodded. "Yeah, refining too!"

"Very good, Ms. Pie. Anything else?"

"Yeah, one more thing..." she muttered, walking over to one of the pull-down screens. She yanked it, pulling down a map of Equestria.

She talked as she looked up at the detailed map. "I didn't know I could actually use all this stuff for something. Tell everypony here to start making massive bulk purchases from every party supplier in Equestria. If they run out, use some bits to start some party supply companies."

Short Sell leaned forward. "What are you planning, Ms. Pie?"

"With all this money, I could throw a party. A big party."

She turned back to Short Sell, her grin stretching from ear to ear. "The Ultimate Party."