"...The test ends when you open that door."

Princess Luna sighed as the door shot open, before she had even finished the last word of the sentence. She looked down at the young colt who had done so with a look of barely concealed annoyance. The colt in question was a brown unicorn with a black mane, and she had to admit, he was as cute as the button on a teddy bear's nose. He looked up at her with an expression that contained all the joy and enthusiasm of a puppy who had just fetched a stick... and quite possibly with as much guile or intelligence.

She was being unfair. It wasn't his fault, of course. All he'd done was what he had thought she had asked. Every last colt and filly who had walked into this room had done the same, with the only difference being how quickly the door had opened. And that was the problem, in a nutshell...

Admittedly, this particular colt had swung the door open so swiftly and so powerfully that it had nearly been ripped off of its hinges, through pure magical might and the youngster's enthusiasm. He certainly might have a future at her sister's academy for gifted unicorns, but not for what Luna needed.

Looking over at the guard stationed at the opposite side of the room, the princess said, "Take this young fellow out, and give him an endorsement for my sister's school. I'm afraid he hasn't passed the test, but he might have a future elsewhere. Then, send the next one in."

The guard nodded, and escorted the colt out, doing his best to mollify the colt's exclamations of 'What did I do wrong?' as they left the room. It was a familiar refrain by now: Every unicorn who had entered the room had sung a similar tune at the end. They came in, Princess Luna told them what the test was, they opened the door, and upon hearing that they had failed to pass the test, they were, all of them, simply shocked. Hadn't they done as the princess had directed? And the statement, on the surface, was so simple. They did exactly what they thought she had said, but not a single one of them understood what she had meant.

She'd even taken the additional step of having one of the younger member's of the palace staff masquerade as one of the participants, and had that one come in first, open the door loudly enough that every pony in the hall could hear it, then be escorted out, looking dejected. All of that should have rung warning bells in the heads of the youngsters, that this test was more complex than it seemed on the surface. But instead, each participant repeated the same mistake.

Maybe it was too simple a test? Or maybe too complex? If nopony actually passed today, Luna supposed that she'd have to take into account the age of the ponies participating, and adjust the test accordingly. These were ponies used to being told what to do by their parents, after all...

There had to be an easier way to find a student.

Celestia's student, now a princess, Twilight Sparkle, was doing well in her duties, and while Luna had expected her elder sister to begin taking on a new student shortly after Twilight's ascension, the princess of the sun had deferred taking on a new protege.

The conversation had been short and simple...

"Luna, I'd be happy to take on a new student, now that Twilight has begun stepping fully into her new role as a princess," Celestia had said, smiling cheerfully. "But I've been teaching students for a thousand years now, with varying levels of success. I'd like to see how a student you've trained would turn out: I think I could learn a great deal by observing how you interact with your student. I'll wait until you've gotten your own protege, and then I'll start looking for mine."

Luna had been surprised by the idea, but had practically jumped at the chance. Equestria was filled with eager young ponies who would be happy to learn under a princess, any princess. However, after some thought, the younger princess had realized that, unlike her sister, a loyal student was the last thing that she needed...

Shaking her head to break herself from her reverie, Luna looked around the 'testing chamber', as she had come to think of it as the day went on, and checked to make sure that everything was in order, shutting the 'testing door' as she did so. Plain grey stone walls, an uncarpeted floor of polished marble, and lit only by a glowstone lamp in the ceiling. There were no distractions, and the only thing breaking the monotany of the room was the entrance, and the door behind her. To think, last week this was just a store room for old furniture. With but a single command, the room had been cleared, cleaned, and readied, and the heavy furniture moved across the palace to another storeroom by the cleaning staff. An arduous task, but it had been done without question.

There were so many things a princess could do with just a single command... and some of those things could be quite terrible...

"Your highness, there's only one left," the guard said, sticking his head in through the door. "And, um...." He hesitated, seeming unsure as to how to phrase his next sentence.

The guard in question, Captain Thunderclap, was a decorated veteran of several campaigns, and one of the few members of the guard to come out of the changeling invasion with something like glory, having rallied his comrades and led them in an assault to retake the palace, while most of the officers of the guard had been too surprised to react to the sudden invasion. This was not a stallion who was prone to hesitation or lacking in self-assurance.

"And what, captain?" Luna asked, an eyebrow raised.

The guard gulped, then said, "She's an earth pony, your highness."

An earth pony? That was most definitely unexpected. Luna thought back to the flyer that she'd had circulated around Canterlot, and had posted across the various towns, cities, and villages all across Equestria. Those announcements, stating that Luna was looking for a new student, had gone literally everywhere. Even Cloudsdale had received a dozen copies, in spite of there being practically no unicorns in the floating city of pegasai.

It was mostly for the sake of political correctness, of course. Likewise, the flyer had announced that anyone was welcome to try. That was 'anyone', not 'anypony': There were plenty of creatures in the world that could use magic that were in no way equine, and Luna certainly would not turn away a potential candidate just because he or she wasn't a pony.

An earth pony, though. Certainly an unusual turn of events. But also, potentially, an interesting one...

"Show her in, captain," Luna said with a nod.

Thunderclap pulled his head back into the hallway beyond quickly, and a moment later, walked in, escorting the earth pony filly in question. As the captain took his position by the exit, Luna studied the latest applicant. Admittedly, she was a cute little thing, if a little on the skinny side. That in itself was a bit unusual: Barring a few unique examples, most colts and fillies either sat right at the ideal body weight for their age, or were somewhere above it, and almost never below it.

She had a pink coat, a purple mane, and clear blue eyes, and if a bit dirty, she definitely seemed eager. Bright eyed and bushy-tailed, so to speak. The fact that she was slightly dirty also raised a flag in Luna's mind: Every other applicant had been scrubbed clean to the point that Luna had expected them to gleam and glisten. The fact that this youngster hadn't apparently taken the time to wash was curious indeed. Why hadn't her parents at least had her bathe before coming to the palace?

After the test was over, Luna had a number of questions that she'd need to ask.

First things first, though...

"And what might your name be, young lady?" Luna asked, smiling down at the young filly.

"Morning Glory, your highness," the filly in question responded instantly.

Luna nodded, and asked, "So, Morning Glory, you're here to take the test for becoming my student?"

Glory nodded and said, "Yes, your highness."

"Before we begin, may I ask why?" the princess asked, curious.

"I want to learn magic," the filly answered without hesitation.

"You do?" A note of disbelief colored Luna's tone, in spite of herself.

Rolling her eyes, the filly said, "Yes, I do. Yes, I know I'm an earth pony, not a unicorn. Yes, I know that every other applicant is a unicorn. And yes, I know that earth ponies aren't known for being able to do magic." The way she recited that implied that she'd been giving those answers all day, likely since the moment that she'd first shown up.

Clearing her throat, the filly said, "But I love magic. I can't give you a reason why, I just do. I've read every book that I can on magical theory and application, as small a supply of books like that as there are in Cloudsdale. It's all unicorn magic, though, and it doesn't really tell me anything I can use. If I want to learn magic, I need a teacher, and if there's anyone who might be able to teach an earth pony how to use magic, it would be you or your sister... your highness."

An earth pony filly... from Cloudsdale? Curiouser and curiouser. The number of earth ponies in the flying city couldn't be higher than a dozen, since most earth ponies preferred to keep their hooves on solid ground...

Nodding, after a moment's thought, Luna said, "Very well. I will give you the same test that I have given every other applicant. If you pass it, then we will discuss your future as my student. If not, well, we'll see what else might be done." An unusual filly like this one shouldn't be turned away out of hoof, and even if she didn't pass the test, perhaps Celestia would be interested in educating the young filly. The novelty of a non-unicorn student, after a millennium of teaching unicorns exclusively, might appeal to the elder princess.

The young filly nodded. "I'm ready when you are," Morning Glory stated, her expression almost comically serious.

Smiling, Luna said, "Very well. I will warn you, not a single applicant has managed to pass this test to my satisfaction. Do you think you can succeed where dozens have failed today?"

"I don't know if I can, but I'll do my best," Morning Glory answered immediately. If the possibility of failure daunted her, she didn't show it.

"Good," Luna said, and then, with a more formal tone, she asked, "Do you see the door behind me?"

The filly made a show of looking at the door. It wasn't special looking in any way, shape, or form, except perhaps that it was an old door that had seen better days, and might need a little mending where the hinges were concerned. After a moment, Glory looked back at Luna and said, "I see it, your highness."

Luna gave a regal nod, and announced, "The test ends when you open that door."

The look of confusion on Morning Glory's face nearly caused Luna to burst out laughing. After a moment, the filly tilted her head to the left, and asked, "Seriously?"

Luna nodded, and said, "Seriously." 'And congratulations,' the princess thought to herself, 'with that one question, you've managed to do better than every other applicant, combined.'

The little filly paused, then narrowed her eyes in suspicion and asked, "You're not going easy on me just because I'm an earth pony, are you?"

Luna immediately shook her head, and said, "I assure you, I am giving you the exact same test that I have given every other applicant."

"And they all failed the test?" Morning Glory asked, an eyebrow raised.

"Every last one," Luna stated bluntly.

"Right," Morning Glory said, then a small smile crossed her face. "'The test ends when you open that door.'" She pondered that a moment, then asked, "If I try to open the door, will you do anything to stop me?"

"Not at all," the princess of the moon answered, "not at all."

"Is the door locked in any way, magically or otherwise?" Morning Glory asked, studying the door again.

"No," Luna answered, a small smile forming on her face.

Morning Glory gave this a moment of thought, then inquired, "Is there some sort of monster that tries to eat me if I try to open the door, or tries to stop me from opening it in any way?"

"A guardian? No," Luna answered, then chuckled at the thought. A guardian creature? On that door? Just the idea of it was absurd...

The filly turned her head to the right, and asked, "What IS on the other side of that door?"

"It's a broom closet," the alicorn stated immediately. "If you like, I could show you."

"I... don't think that will be necessary," Morning Glory said after a moment's thought. Then added, "Would I pass the test, or fail the test, if you opened the door for me?"

"Neither," Luna answered, then added, "The test ends when you open that door. Not when I open the door."

Morning Glory gave this some thought, then asked, "But opening the door doesn't necessarily mean I pass the test?"

"True," Luna said, and then gave another small chuckle. Not a single applicant had considered what the princess was saying. They had only heard what she had said, without giving any thought to the actual meaning...

"If I opened the door right now," Glory began, "would I pass or fail the test?"

Good question. "I wouldn't say you'd pass, exactly," the princess admitted, "but you'd come a great deal closer than all the other applicants have."

"Fair enough," the filly said, then asked, "May I ask the guard a few questions?"

"Feel free," Luna responded, after a moment's thought. She saw no harm in it, really.

Morning Glory turned to Captain Thunderclap, and asked, "This is the same test she gave all the other colts and fillies?"

The captain nodded immediately. He'd been present for every test today, so of course he'd know.

"You promise?" the filly asked, with the sort of absurd seriousness that only a five-year-old filly can manage.

"If I lie to you here and now," the captain announced with the formality one might normally reserve for a blood oath, "may my wings fly off without me, and never return."

That seemed to satisfy her. "Okay," Morning Glory said, then rubbed her chin. "Do you know how to pass the test?"

"No," Thunderclap admitted, "but I can tell you how all of the other applicants failed, if you like."

The filly, an eyebrow raised, asked, "How?"

"They opened the door," the captain stated, a slow smile crossing his face. Luna only barely managed to stifle an unladylike guffaw of laughter at that. Funny though it was, it would likely hurt the youngster's feelings to hear the princess laughing at a joke at another's expense.

"Thank you for your help," Morning Glory said, a hint of sarcasm in her voice.

"My pleasure," Thunderclap replied without a trace of irony.

Turning back to Princess Luna, the youngster asked the one question that Luna had been hoping somepony would ask her at some point today...

"Just what is the purpose of this test?"

Luna smiled, and said, "After the test is over, I'll explain it to you, pass or fail."

"Promise?" Morning Glory asked, her expression the very picture of skepticism.

"Cross my heart, hope to fly, stick a cupcake in my eye," Luna immediately answered.
--------------------------------

Meanwhile, in Ponyville, Pinkie Pie suddenly went very still for a moment. If words could be put to the feeling that had run through the pink pony's body, it was as if there had been a great disturbance in the force, as if someone very powerful had made a Pinkie Pie swear, but it had not yet been kept. After a moment, the feeling passed, and the party pony went about her business, although every so often, she'd look in the direction of Canterlot with a suspicious glare, as if daring someone to try and do something...
----------------------------------

"Okay," Morning Glory said, after a moment. "So, is there a special way of opening the door that will guarantee that I pass?"

"No," Princess Luna answered immediately.

"Any sort of secret knock or password?" Glory asked, tilting her head to one side again.

"No," came the alicorn's prompt response.

Tilting her head the other way, the filly asked, "And if I open the door, right now, I'll still fail the test?"

"Yes," Luna said, then paused, and said, "Although you're a lot closer to passing the test than you were before."

Morning Glory sat, and her face scrunched up as she thought. For three or four minutes, she sat there, not moving, just thinking.

Finally, the filly blew a breath through her lips, with a distinctive 'Pbpbpbpbpbpb' sound, and then threw up her hooves in frustration and admitted, "I don't get it: Just what is the point of this test? I mean, you're asking me to do something any pony could do. I mean, even you could do it, and a lot easier than I could! You're taller than me, so you wouldn't even need to stretch to reach the knob, and you wouldn't have to strain to open it, even if you didn't use magic!" Finally, an expression of frustration clear upon her face, Morning Glory asked, "How am I supposed to pass the test?!"

Smiling, Luna said, "By asking how you're supposed to pass the test, and then opening the door." At the filly's flabbergasted expression, the princess added, "Congratulations, by the way. If you will kindly open the door, we'll begin discussing your future as my student."
------------------------------------------

"It has to do, in part, with how the words of a princess can be... misunderstood," Luna explained over a late lunch (And in Ponyville, Pinkie Pie breathed a sigh of relief, thankful that she wouldn't have to try and force an alicorn to keep a Pinkie Pie swear...). "There was a king, long ages ago, who sought to expand his power in both the political arena, as well as in other areas, but was hindered at every turn by a sage who was well-loved and respected by his subjects, and by many others in foreign lands. The king and the sage were in conflict for many years, but things never went beyond raised voices. Then, one day, after a serious political defeat, the king was heard to exclaim, 'Can no one rid me of that meddlesome sage?' A few of the king's vassals interpreted that as a command, and..."

Luna paused, and considered her words carefully. This was a filly of five, after all. "I'll spare you the details, but those vassals did as they thought the king commanded, and 'that meddlesome sage' was no longer a problem for the king, or at least not directly. However, in doing so, those vassals ended up causing their king a great deal more frustration than the sage ever had. The king lost a great deal of power and influence, both at home and abroad, and ended up being hated by many. All because his subjects misinterpreted what he had said."

"And that was what the test was about," Morning Glory said, as she swallowed a mouthful of biscuit. "You wanted somepony who took the time to try and understand what it was you meant, not blindly trying to do whatever they thought that you said."

"Exactly," Luna said with a smile. "I've been... away for one thousand years, and so much has changed: Technology, culture, traditions, and perhaps most importantly, our language. Words mean different things than they meant back before my banishment, and sentences were structured differently as well. It would be very easy for me to say something that could be interpreted incorrectly, simply because I accidentally spoke in a way that sounded as if I was using a metaphor or euphemism that is common in modern society, but was non-existent a thousand years ago, or vice versa. The young colts and fillies before you were so eager to please that they immediately jumped into action, and failed the test, because they thought they knew what I was asking of them. It never occurred to any of them that when I said that the test ends when they opened the door, I was speaking of how they might fail the test, rather than pass it. You actually stopped, asked questions, and thought. That is what I need most in a student: Somepony who will stop, listen, ask questions, and above all else, think. I'm sorry to say that, as today has proven, ponies who do so are much more rare today than they were a thousand years ago."

'And,' she added silently, 'I wanted a student who didn't reflexively obey my every word because, if I ever become Nightmare Moon again, I don't want to drag my student down with me because she was slavishly following my every utterance without considering whether what I was doing was right or wrong...'

"So," the princess announced formally, a bright smile still on her face, "you have succeeded in passing the test. I cannot say if I can teach you magic, but I am certainly willing to try. If it proves impossible, well..." she paused, then said, "there are many other things, asides from magic, that I can teach you. I'll just need to discuss your boarding arrangements with your parents, since having you commute every day from Cloudsdale to the palace and back again would be a little excessive."

Morning Glory, who'd been munching on an apple just slightly smaller than her head, froze, then gulped loudly, and then said, "Yeah... about that..."
---------------------------------

Princess Luna had made great strides in controlling the volume of her voice. Truly she had. The Royal Canterlot Voice was rarely heard these days, save in situations of extreme duress and shock, and even then, the voice was usually many decibels lower than it once was. That volume control was something she was very proud of, as well as the self-control that kept her, most times, from defaulting to that tone in the first place.

Which was probably why she had not accidentally blasted Morning Glory's head off through an unintentionally weaponized version of the legendary formal mode of address.

Her voice carefully controlled, Luna asked, "...So let me see if I've got this straight: You're an orphan, who was raised in the Cloudsdale orphanage. When you heard that I was looking for a student, you ran away from home, and journeyed, on hoof, all the way here? Over the course of a week?" This was followed by a glare that might have etched steel, if it did not sublimate the metal into a vapor first.

Morning Glory, seeming to be mute from fear, only nodded.

Princess Luna was quiet for a moment, and then her glare turned icy as she said, "While your resolve, drive, and determination are admirable, I trust that you will not take such unnecessarily reckless actions in the future... yes?"

Morning Glory nodded once more.

"Very good." Luna took a breath, and called out over her shoulder, "Captain Thunderclap!"

The captain entered the dining room, and saluted.

"How quickly can you arrange an honor guard to escort me to Cloudsdale?" the princess asked without preamble.

"Less than an hour, your highness," Thunderclap answered immediately.

"Good," Luna said with a nod. "I'll need you to escort this young lady and I there." At the worried look on Glory's face, the princess added, "If I am going to take on the role of this filly's legal guardian, I imagine there will be a few forms to fill out at the Cloudsdale orphanage. We'll need to pick up a few of her things as well, along with a few other trifling tasks." With a smile, she added, "While I suppose that such things could be done via the mail, I've always felt a personal touch helps to smooth things over more swiftly." The captain promptly nodded, and marched off to make the arrangements.

As Morning Glory began to smile, Luna couldn't help but to mirror it herself. In for an acorn, in for an oak, as they say. The princess had decided to become a mentor to the youngster anyway. Being a parent to her as well couldn't be that much harder... could it?

Author's Notes:

Thomas Becket, who was killed because a king couldn't keep his mouth shut. Be careful what you wish for, or you'll be the man who goes down in history for ordering the assassination of a saint.