It was a typical Summer day when the stranger appeared.
For Ponyville, a typical Summer day meant perfect weather: a few clouds for decoration, enough sunlight to raise the air slightly above room temperature, and a light breeze to tickle your feathers. Days like these generally made Fluttershy nervous, because they were the only kind of days on which monster attacks would occur.
On this particular day, Fluttershy awoke just before dawn. In addition to the scheduled weather, a note on her calendar indicated that Ponyville was nearly a week overdue for a major disaster. After living in Ponyville for many years, Fluttershy had learned to prepare for these sorts of contingencies. Just to be on the safe side, she intended to get her shopping done early. This would help her to avoid the potential hassle of something like Ponyville's dam bursting or perhaps a giant rampaging muffin.
So Fluttershy left her home at the crack of dawn, when most other ponies remained snug beneath their quilts. When she arrived at Ponyville Square, the vendors were still setting up shop.
"Morning, Fluttershy!" said Roseluck, from where she was putting her flower stall together. "Lovely day, isn't it?"
"Oh, good morning Rose," replied Fluttershy, with a smile. "It certainly is lovely, thanks to ponies like you."
Roseluck blushed, even though Fluttershy hadn't intended it as a compliment.
Crafty Crate's stand was already set up. Crafty was a no-nonsense sort of pony who preferred business to socializing, and on occasion Fluttershy found him to be intimidating. Crafty didn't like ponies dilly-dallying around his wares, so she had learned not to approach his stand until she was ready to purchase. However, today Fluttershy was only looking for one product. That made things much easier.
"Hello, Crafty," said Fluttershy as she walked up to the fruit vendor's stand.
"Heya, Shy. Lookin' for any fruit today?" the large pegasus asked her. Crafty cleared his throat, then unceremoniously spit a cherry pit out of his mouth and onto a nearby patch of grass.
She glanced at his wares and sighed with relief. There were plenty of cherries available, which meant there was no lesson for her to learn at the moment. Fluttershy didn't mind her lessons, of course, but surprises tended to make her feel a little anxious.
"Yes, please. How much for a dozen cherries?" she asked.
"Two bits," said Crafty Crate.
Fluttershy removed her coin purse from her saddlebags and set it down on the stand before opening it. She upended the purse, and out fell exactly two bits. There had been no need to check her money before leaving for market, of course. Little details like that took care of themselves.
As Fluttershy took her cherries in wing and placed them in her saddlebags, she turned around just in time to see something very unusual. An earth pony with a coral pelt and dirty mane winked into existence right in front of her, without even a magical flash of light! It happened so silently and suddenly that Fluttershy initially wondered if her eyes were playing tricks on her. Nopony else seemed to notice, so Fluttershy assumed she was the only witness.
Fluttershy was tempted to ignore the stranger, but something like this would never happen without a reason. So, she steeled her courage and walked up to the mystery pony.
"H-hello there?" asked Fluttershy, her voice barely above a whisper.
"Fluttershy?" the stranger gasped, and her face paled. Then the poor thing tripped over her own hooves and landed face-down in a muddy puddle.
The pathetic nature of the stranger helped Fluttershy resist the urge to run. The other pony was female, but it took her a moment to be sure. While the other pony's muzzle was small like a mare's, it was oddly crooked. Something about her jaw seemed out of place, and her ears weren't perfectly even. Her mane was a tangled mess, and she very much needed a bath—even before falling into the mud. She wore no clothing, so at least that was normal.
The odd pony seemed to be in a state of shock. She closed her eyes and continued to lie quietly in the mud.
"Are you okay?" asked Fluttershy, crouching to speak face to face. She wondered how the mare knew her name. She was certain she'd have remembered meeting such an unusual pony.
Then again, even though Fluttershy didn't like thinking about it, she was resigned to the fact that she was now a celebrity. When Twilight Sparkle became an alicorn, her ascension broke Princess Celestia's anti-fame enchantment. Celestia had been using magic to keep Twilight and her friends free from the trappings of high status, but even alicorn magic wasn't strong enough to block fame from embracing an actual princess. Now everypony in Equestria knew that Fluttershy and her friends were the Bearers of the Elements, that they'd saved Equestria on numerous occasions, that Rainbow Dash had performed the legendary Sonic Rainboom several times, and so on. Fluttershy didn't care for being famous, but it seemed to make Rarity and Rainbow Dash happy, and that was nice.
Fluttershy shook her head to derail that train of thought and refocus her attention on the stranger. The mare had tucked her tail up between her legs and beneath her barrel, getting mud all over her haunches in the process. She had no cutie mark to speak of, and her pelt was oddly-textured. Her eyes were clamped shut and she hugged the ground defensively.
It was rare for Fluttershy to encounter a pony more fearful than she was, and it seemed obvious that this mare had a friendship problem. Fluttershy knelt down in the mud next to the stranger and gently stroked at her knotted mane. "It's okay, I won't hurt you. What's your name?"
The stranger coughed a few times, then said in a horse and raspy voice, "It's... I don't have one." She kept her eyes shut, and the muscles in her back tensed up as Fluttershy touched her.
"Oh my goodness! You don't have a name?" said Fluttershy, her voice filled with wonder. "That won't do at all. Let me see if I can draw it out."
Fluttershy reached out and grasped the pony's forehead, right where the horn would be if she were a unicorn. Then she paused for a moment in thought, focusing her mind on the Name of the stranger. After several seconds of intense concentration, the mare's Name still wasn't coming to her. Nomenmancy never failed on ponies or donkeys, so this was yet another oddity. Perhaps this was a lost changeling, thought Fluttershy.
"That's strange, I can't seem to pull out your Name. But we must call you something. I suppose I'll have to think up a name for you myself," said Fluttershy, and then she smiled. "I know! I'll call you Mercy. That's one of my favorite words."
Mercy shuddered at the sound of the word, but said nothing. Her ears lay flat back against the tangles in her mane, and her breaths were short and quick. She shivered, even though the air was balmy.
"You sound awfully thirsty, Mercy. Let me get you some water," Fluttershy suggested, very gently.
"No, it's fine," said Mercy, her eyes still closed. "Can... can I just lay here for a while?"
Fluttershy thought that was an awfully strange request. "You're not in the way, so I suppose so. But lying here in the middle of the market can't be much fun," said Fluttershy. "Why don't you come with me, and I can get you cleaned up?"
The stranger opened her eyes just a little. "If I can wait here until dark, I'll be on my way. Then you won't have to worry about me anymore."
"Hmm. I think I should go get Twilight," said Fluttershy.
"No!" yelped Mercy, her eyelids snapping open. "I mean, um, there's no need to bother her." She awkwardly shifted her legs in the mud.
Fluttershy was considering getting Twilight Sparkle anyway, when she looked up and saw Rarity within shouting distance. "Wait here for just a moment, Mercy. I'll be right back, I promise," she said.
Mercy sighed. "Of course you will," she said.
Fluttershy stood up. Since the mud had only touched her briefly and she had no lesson to learn from it, simple physics caused it to slide smoothly off, leaving her legs perfectly clean. She cantered up to Rarity.
"Rarity, I'm so glad to see you!" said Fluttershy. "I'm in the middle of a friendship problem, and it's a tricky one. I think I might be in over my head."
Rarity looked over Fluttershy's shoulder and saw the strange pony sitting in the mud.
"The disaster in the mud?" said Rarity. "That poor dear. We need to get her cleaned up immediately."
"That's what I said, but she doesn't want to move. She said something about lying there until it gets dark? And she didn't know her Name! I couldn't pull it out, so I've been calling her Mercy," said Fluttershy.
"My Heavens! Sounds like she's lost her mind. Perhaps she wandered out of Ponyville General?" said Rarity.
"I can hear you," Mercy called out.
Rarity walked up to the strange mare and studied her closely. "Darling, listen here. My name is Rarity. You are going to allow Fluttershy and I to help clean you up, and that is simply all there is to it."
Mercy groaned and planted her face in the mud, then awkwardly wiped sludge from her eyes with a hoof. "Buck," she mumbled under her breath. "I mean, buck. Wait, what did I just say? Horse apples!"
"Such language!" said Rarity, aghast. "Though in your given state, I suppose it's understandable."
"What are you talking about, Mercy?" asked Fluttershy.
Mercy shook her head. "It was a slip of the tongue. Look, if I tell you everything I know, will you leave me alone?"
"Certainly not," said Rarity.
"Oh, let's give her a chance," urged Fluttershy, kneeling down once again in the mud. "Go on, Mercy. You can tell us."
Mercy took a deep breath and cleared her throat. Her voice remained low, but lost some of the raspy quality. "I'm a secret agent on a mission to save Equestria."
"Mhmm. Of course you are," said Rarity, as flatly as possible.
Mercy turned her head away. "I don't expect you to believe me, but I need to get to the edge of the Everfree Forest so I can complete my mission."
"Well, then why don't we walk you there?" asked Rarity, pointing toward the forest. "It's about a mile in that direction; you can't miss it."
"Rarity!" admonished Fluttershy. "I'm sorry, Mercy, but you really don't want to go there. The outskirts of the Everfree is a very dangerous place, even during the daytime."
"I know, and I accept the risk," said Mercy. "This is a life-or-death mission. The fate of Equestria hinges on my success."
"Hmm. Well, if you really do have a quest in the Everfree, I believe our friends can help you," offered Rarity.
"No. I have to complete the mission alone. It's the only way," said Mercy.
"Can you tell us what the quest is, at least?" asked Fluttershy.
Mercy shook her head. "It's top secret. And I would walk there, but I'm unsteady on my... on my hooves, right now. And I don't want anypony to see me..."
"I'm afraid it's a bit late for that, darling," said Rarity, raising a brow.
Mercy blushed and winced. "I mean, I don't want them to see me naked," she whispered.
"See you naked? But why not?" said Fluttershy.
"Fluttershy, that is a very personal question," said Rarity. "Mercy, please allow me to speak with my friend in private for a moment."
Rarity pulled Fluttershy several hooves away and whispered to her. "Fluttershy, this pony is completely insane."
Fluttershy pursed her lips in thought. "If she's crazy, then this is almost certainly a friendship lesson, not an adventure quest. I'm not sure a friendship lesson makes sense, though. What would the lesson be?"
"You have a point," said Rarity. "And her story certainly sounds like an adventure quest. Still, my bits are on friendship problem, even if the lesson isn't clear yet."
"But what if she really is on a mission to save Equestria?" asked Fluttershy. "We might need to hurry."
"You're right. We need to get Twilight," said Rarity. "We should just take her to the castle and clean her up. If only she weren't so mule-stubborn about it!"
"Why do you think she needs clothing?" asked Fluttershy. "If anypony could guess, you could."
"Well, she must be embarrassed by her body. She doesn't have a cutie mark, for one," Rarity pointed out. "Her muzzle looks a bit crooked, too. Imperfect plastic surgery, or else she had it broken during some unusually valuable lesson."
"You know, for a moment I thought she was a hinny. But her body proportions say pony," said Fluttershy.
"Yes, definitely some breed of pony. No amount of nip and tuck can give a person the natural leg-to-barrel proportions of a pony," said Rarity.
"But her Name won't come out, Rarity," said Fluttershy. "Do you think she might be a changeling?"
"Now that would be the saddest example of a changeling I've ever seen," said Rarity. "I suppose it could explain the lack of a true Name, but then her appearance makes no sense. Why would a changeling want to look like such a terrible mess, let alone request clothing? Let's face it, Fluttershy, we simply don't know what we're dealing with yet."
Rarity turned back toward Mercy and put on a large, less-than-genuine smile. "Alright then, dear. What will it take to get you up and moving?"
"Maybe... a cape? Anything that can tie about the neck and belly," said Mercy. "A tarp would be fine. Or, maybe just a box with a hole in one side."
Rarity gasped. "Heavens no! That would be an insult against fashion itself!"
"I'm not trying to star in a fashion show. I just need to get to the forest. Then I can give the box back to you," said Mercy.
"We should really clean you up first," said Fluttershy.
"How about a robe. Would that do?" asked Rarity.
"If it's long enough to cover my... my rump," said Mercy. "Like, my tail and legs too. I don't want to ruin a robe if a tarp will do, though."
"Well, just so you know, darling, nopony can see anything back there right now, even if they were rude enough to look," said Rarity. "Your haunches might be mostly visible, but your backside is completely covered in mud. Be that as it may, I'll go ahead and fetch you a long robe."
As Rarity trotted off, Fluttershy knelt beside Mercy. "Everything's going to be just fine, you'll see," she said, wearing a bright smile.
"That's what I'm afraid of," said Mercy, and she tucked her chin back into the mud.