I put out a hoof in front of the others. "Let me see what's going on, first."

Aiko frowned and reached past me for the door. "You don't even know how to talk to a doctor, besides, they're doctors. Don't act like you're in some kind of action movie." She pushed in the door and stepped inside quickly. "Hello? Sorry for bothering, are you open?"

It was a little dim inside, but I could see light coming from further in. Emerging from there came a lean man with black hair. Most Japanese people seemed to have black manes. I couldn't even imagine trying to live with an entire country that looked like me! He had a fancy badge on his shoulder, and even a stick and some hoofcuffs. Was he a guard?

"Sorry, but the clinic is closed right now, and everyone's being urged to stay inside. You really should go home right--" He trailed off as he got a good look at me. Even with my mask on, a straight look could see my bright pink fur, to say nothing of my exposed forehooves. "W-what?"

Aiko stepped in front of me and pointed at herself. "We need help! We're turning into horses!"

Emma moved aside Aiko. "Calm down. They don't need hysterical girls to deal with."

"I have pretty good reason to freak out," she argued with a frown.

The guard shook his head as he backed up. "Look, I'm going to have to ask you all to stay where you are. This contagion is extremely transmittable, and the doctor's don't know how, yet." He fished out a face mask and got it on super quick.

A voice came from the back, "Are they infected?" A new face poked free, younger, with a messy mane. "We could use one that isn't uncooperative."

Aiko took a quick step back. "I'm not a test subject!"

Emma, on the other hoof, stepped forward. "If it helps make things better. This is alright, right, Pinkie?" She looked at me for permission. Why was she asking me for permission? It was kind of flattering that she trusted me so much. I gave her a hooves up with a bright smile. If we could help, we should.

The guard turned to look over his shoulder at the other person. "One of them is... I think you should see this."

The man stepped into full view, wearing doctor's stuff. He even had a stethoscope dangling around his neck. I noticed he had a smiling human female drawn brightly on his upper right chest? Was that a badge of the doctors of this office? Strange, but cute. He looked between the three of us before settling on me. "Excuse me, ma'am, but could you take off your mask?"

Well, there wasn't much of a reason to hide from these people, I supposed. I quickly had the mask off and tucked it away in time for them to gasp in surprise. "You really are a little horse!"

I pointed at myself. "Born and raised. My name's Pinkie Pie, nice to meet you." I offered a hoof at them, but neither advanced to take it.

The guard shook his head. "As I said, we don't know what transmits this, so please keep your distance. This is a very serious matter."

Aiko glanced at me, then the others. "Wait, is this a disease?!"

Thump! All eyes turned to the front doors, where someone had bumped against it. They scrambled at it with misshapen hooves and made low noises that had no words in it. It almost looked like they wanted to come in, but couldn't figure out to push the bar properly. They bumped against the door once more time before staggering off, moaning the entire way.

The doctor let out a small breath when the quasi-pony left. "That's happened once in a while. That's why we're excited to have you, coherent and conscious. Most people seem to become almost catatonic, at least in terms of thinking ability. Others become dangerously manic. In either event, they're dangerous."

Aiko looked around the dimly-lit office slowly. "Is that why the lights are turned down? And are you two the only ones here?"

The guard hiked a thumb into the back. "Doctor Sato is working."

The other doctor pinched the bridge of his nose. "Doctor Sato is always working, and I'm not sure how much progress he's making. Anyway, I'm Doctor Kazuki Kudo." The same magic that translated them slipped the first and last names around for me without my even realizing it at first. He had said Kudo first. "Please, if you would be willing to work with us, we could really use some practical study." He paused. "Did you say born and raised?"

I perked an ear at him. "Yepperoni. I've been a pony since I was a wee little filly."

The guard threw a hand towards me. "Is that possible?"

Doctor Kazuki smiled. "Well, it means one of two things. You're suffering from a mental breakdown like many of the other victims, or... We just found patient zero." He dropped down to a crouch, becoming face-to-face, if still across the room, from me. "Tell me about your past."

Oh wow! That was a big question! "Well, you see, I was born on a rock farm..." I began to give my life story. To my surprise, he didn't cut me off. Ponies usually asked me to stop by the time I got to my third birthday, but he kept making a 'go on' motion once in a while, so I kept going on. He was a great listener!

Aiko ended up being the interruptor. "Why are we drilling her about her childhood? I'm turning into a horse! She suddenly moved towards the doctor. He scrambled to his feet and the guard stepped in to grab Aiko. He got her by the wrist, but she was really worked up and swung her other hand around, slapping the guard across the face. "Let me go! He's the doctor, he should be helping me instead of interviewing an alien!"

The guard managed to get her other hand and spun her around. He shoved her roughly against a counter and cuffed her on the spot, but he didn't do any real harm to her. "I'm sorry, but you were asked to stay away."

She kicked and thrashed around. "This is a violation of my rights! I didn't do anything illegal! Let me go this instant!"

Emma shrank back to my side and whispered, "Is there anything we can do?"

I looked up at Emma, then I smiled at Aiko. "It'll be OK, Aiko. We're here to get help. Relax."

Aiko went calm for a moment, nodding placidly before her rage returned and she suddenly pushed back, knocking the guard off balance. She spun around, still cuffed.

Huh, now I may not be the fastest pony at times, but it was pretty obvious my words had an effect on Aiko and Emma. Emma seemed to accept it, while Aiko fought against it as hard as she could. "Aiko, they can't help you if you're being a big scary meanie face at them."

Doctor Kazuki moved towards a cabinet full of little glass jars and pulled out a needle. "You're obviously very worked up. You need to calm down right now, miss. You don't want to become like another of the victim's outside, do you?"

Aiko's eyes widened at the sight of the needle and she backed away from it. The guard reached for her and she shrieked. She had two options left to fight, and went for a bite. She got him on the arm and he howled in pain as she clamped down harder and harder. I couldn't just stand there! I raced across the room and ran into her, knocking her off of him and to the ground in a heap. I jumped onto Aiko and held her to the ground. "This is your fault! This is all your fault!" Aiko screamed and struggled until Kazuki stepped over carefully and gave her a poke with that needle. Her struggles started to slacken and fade, until she was asleep beneath me.

I pulled out a pillow and set it under her head, then hopped off of her. "Phew. Sorry about all that."

The guard was holding his new injury with his other hand. Doctor Kazuki inspected the bite with a thoughtful frown. "Her teeth were unusually blunt, but she still managed to break the skin."

"Am I infected?" He asked with a haunted face.

Kazuki shrugged softly. "You may be. We won't know until symptoms appear, or not. I'm sorry."

The guard took a slow breath. "Right, fine. I signed on to serve my community. This doesn't change anything." He turned to look at me. "She may not be wrong, you know. If you are the first little horse, then this probably is your fault."

Emma slid in front of me. "Pinkie didn't do anything wrong. She's tried to help out every way she can."

Kazuki smiled broadly. "You're both right. I'm more convinced than ever that you're patient zero. But you are here to help us?" I nodded quickly. "I thought so. Now, to explain, I think there is some way that you've caused this infection, Miss Pinkie."

Oh, shoot. I didn't reverse my names like he had. "Pinkie's my first name, Pie's my family name."

"Ah, sorry. Miss Pie. Have you bitten anyone?"

My eyes widened a little. "What? No! That'd be awful."

Kazuki nodded. "Have you had any other direct fluid contact?"

Direct fluid? Well... "There were two stallions, human stallions." He raised a brow at me. Fine, he wanted details. "They were back where Emma came from."

"America," provided Emma without prompting.

"One was in her apartment building. I found him on the balcony and we played and... Do you really want every detail?" Kazuki nodded. "I sucked him like a lollipop until he gave me his creamy filling, but then I had to go." Emma looked flushed, and even the guard looked a bit amused. "So, uh, then there were this nice stallion at the airport. I liked him, and we kinda... I lifted my tail for him in the bathroom and he said yes and we had fun." A bit of that suddenly came to me. It... It all made sense. "While he was... doing it... his human willie became a pony willie. I didn't know why at the time. Then I left him. Oh Celestia, it really is my fault." I sank down to my belly a moment, then threw out my forehooves wide. "Nooooooo!"

Kazuki frowned. "Are those the only two? That doesn't explain everything. They were both in America, but I can assure you, there are cases right here." He pointed a pen at the unconscious Aiko, then Emma. "Did you do anything with them?"

Emma flushed brightly. "S-she asked to, before, but I said no."

I nodded with Emma. "I didn't do anything with either of them."

"Then what did you do?" Kazuki leaned in a little. "This is critically important. I'm not here to blame you, but something caused this, and knowing what it is is vital."

I thought really hard about the past few days. "Let's see. I made some cupcakes?"

"Cupcakes?" Kazuki raised a brow. "What were the ingredients."

Emma suddenly gasped. "I did it!" All eyes turned on her. "Back in America, I hurt Pinkie, on accident. Her nose bled a little and I cleaned her up."

Kazuki pointed at her with a smile, looking quite happy about the news. "Ah, blood contact, that's good. I assume Aiko here didn't have that, however?"

"Nope, just cupcakes." I looked over to Aiko. Poor girl. I mean, not that being a pony was all that awful, but it's not like anypony asked her ahead of time. I began pulling out my spare supplies, setting out a container of sugar, spices, and baking powder.

"H-how?" Kazuki knelt down to look over the things. "How were you holding all of that in your mane?"

I shrugged a little. "Always could. I know better than to question it."

Kazuki waved a finger at the three ingredients. "Did you get this from a local store?"

"Oh, no. They're from Equestria." Then it struck me. "Shoot."

"Shoot is right," grunted the guard. "You infected your friends with your cupcakes."

I raised a hoof. "I shared a cupcake with a guy before I reached Aiko's."

Kazuki rose back to his feet. "Did you give anything else from your home away?"

"Well..." I tapped my chin a few times. "I sold my bits, for yen." He looked at me oddly. "Bits? Gold coins."

He sighed softly. "Alright, I have a good enough picture of how this began."

A new woman emerged from the back. "I'm quite busy, as you are well aware. What is all this noise out here?" She paused and peered at Emma and I, with Emma's ears on display and my pony face. "Is there a good, a very good, reason for this?"

The guard tipped his hat towards the lady. "Doctor Sato, we think we found patient zero."

Kazuki clapped his hands together. "No think about it, I'd bet my license on it! Meet Miss Pinkie Pie." I could feel the magic twisting the order around. Wow, Japanese people really must value families. That was nice. "She's volunteered to help us figure this all out, and she's already been a font of useful information."

This new doctor, Doctor Sato, was dressed similarly to Kazuki, had her mane done up in a bun, and no little colorful badge on her doctor's jacket at all, just clean white. "I see." Her eyes fell on me again. "So you're the first infected?"

I shook my head. "Nuh uh. I was already a pony from the start." She looked doubtful. "What? It's true! The only part of me that changed was getting a wing-wang."

Kazuki coughed softly. "Wing-Wang, you say?"

Emma started going red quickly, but I had the idea they weren't going to be happy until they saw it. It was like being with a couple of Twilight Sparkles. They always have to see everything, write it all down, and claim they're geniuses afterwards. They'd be kind of annoying if they weren't usually cute while they did it, and Kazuki was a nice guy, I thought.

I pulled off my trenchcoat and stuffed it away, revealing my entire body to their prying eyes, which included my dangling balls and sleeping shaft. I wasn't feeling specifically frisky, so it was tucked away in its sheath, warm and safe. "See?"

Emma put a hand on my shoulder and squeezed softly. Was she trying to be supportive? That was super nice of her and I smiled up at her.

Sato made a twirling motion with a finger. "Are you transgender, or hermaphroditic? Hermaphroditism cannot work for a variety of reasons, at least as a reproductively viable organism much more complicated than a flatworm."

I didn't understand half the words she said, but I turned around for her and raised my tail, showing off I was still a mare down there too. "What do you mean by that?"

Kazuki dismissively waved. "Not important right now. We're not here to measure fertility. Pinkie-chan, is it alright if I take a blood sample?"

That sounded kind of scary, but Emma squeezed me again and she looked confident, so, what the hay! "Sure, I guess. Go ahead."

He fetched a new needle. "This will sting a moment, but it won't be too bad, and it'll be over in a moment. Just stay still for me." I looked away and he poked me with what felt like a big ole' pinch. A few seconds later he pulled it out and stepped away. "Emma? Could you clean your friend?" Huh? I looked down at my arm to see there was some blood in the fur of my right foreleg where he had poked me, and I realized why he hadn't cleaned me. He didn't want to touch the blood and maybe become a pony too. I guess I couldn't blame that on him.

Emma got some wet wipes and cleaned me up diligently. Just as she finished, she brushed my snout with a few fingers. I turned to her and she kissed me, lips to lips. "Whatever happens, we'll make it through, together." I didn't feel as romantic as she did. I couldn't even tell how much of that was 'her' and how much of it was my weird mind-control stuff. Did she love me because I wanted her to like me? Was she a slave to my every whim? Did I kill who Emma used to be? The thoughts jumbled around in my head almost painfully.

"Emma..." She perked her ears at me. "Emma, do you really like me? Why? I ruined your trip, and hurt your friend, and you. You're becoming a pony, like me, and you're being very accepting of that."

Emma seemed to consider that a moment. "Aiko hurt herself when she decided that being loud and aggressive was more important than being civil."

Kazuki chuckled. "I feel ashamed, to hear an American say that about a Japanese person. Truly these are the end times." Emma looked at him with a shocked expression and he held up his hands. "Sorry, just a bad joke on my part. Doctor Sato, shall we?"

Sato nodded towards the syringe full of my blood. "Let's. The sooner we examine it, the sooner we can verify, or debunk, this wild notion." They went off into the back, discussing little technical details about things I knew nothing about.

The guard let out a loud sigh. "Anyone want some water?"

That sounded really good! "Yes please!"

He fetched some cups from a drawer and filled them up with tap water for us all. As we all sat around and drank, he suddenly grimaced and fished into his cup with two fingers. He came out with a tooth. "Shit."

Emma reached for his shoulder, petting it gently. "I'm sorry."

He threw the tooth aside and grunted, looking annoyed, but it wasn't clear what he was annoyed at most. "I should have been able to subdue her without being bit. I was in poor form, and this is the result."

Emma shrugged softly. "You're only a security guard, right?"

He looked confused then. "No? What gave you that idea? I'm a police officer."

Emma gestured down at his hips. "Where's your gun?"

"Japanese police officers don't use guns." He raised a brow. "We take care of things in a civil fashion, and with even heads, unlike Americans. Do you watch your own news? It's terrible."

I didn't know what they were talking about at all. "What's a gun?"

Emma glanced at me. "I mean, sure... I... A gun is a weapon. A very deadly one."

I frowned. "Why would he have that? He's a good guy."

The police officer, who wasn't a guard after all? Is that what humans called their guards? He chuckled at me. "See, she has the right idea. We're the good guys, so we have to enforce the law without causing more harm than we're fixing. If I had a gun, what would you have suggested, shooting your friend? That might have worked, but then you wouldn't have a friend anymore."

Emma looked embarrassed and drank from her water before replying, "I guess..."

He looked to me. "So, how is it?"

"How's what?"

He reached over and tweaked one of my ears, making me squeak. "Being a horse. You seem to be doing alright with it?"

I clopped my forehooves together. "Well I think it's great, but I'm maybe a little biased on that? Emma?"

Emma twitched her ears at me. "Huh? Oh! Well, these ears aren't bad for hearing things." She reached up and brushed her blue ears gently. "Does this mean I'm going to be a blue horse? Are all you horses crazy colors?"

I flashed a smile at her. "Most of us. Nice bright colors. And that's pony, not horse."

He shrugged. "A pony is just a small horse. I never introduced myself, Sasaki Hiro." The names didn't switch themselves. Was the magic testing me? I wouldn't be tripped up that easily!

"Nice to meet you, mister Sasaki."

He smiled. "Just Hiro will work for now. We're in an awkward situation, the least we can do is treat each other kindly." Aw, I decided he really was a good guy.

"Impossible!" called a female voice from the back. We all looked towards it as a quieter male voice spoke with her and their conversation died down. They were talking, but we couldn't make it out from so far away.

Emma shook her head. "I'm guessing they just proved you're an alien."

Hiro looked me over slowly. "How did you get here, on a flying saucer?"

I pictured flying around on a tea saucer and began to giggle at how ridiculous that was. "I flew on a plane, remember?"

Hiro frowned just a little. "Before that. Before you met Emma. How did you get here, to Earth, not just America or Japan?"

I thought back to that fateful moment. "Well, you see, there was this big problem, and I thought I could stop it from ever happening, so I hopped out and caught the big ball of pony energy and tried to throw it away, but it didn't go away, it just got sent backwards in time a little, and I fell after it, and then I woke up in Emma's apartment."

Emma raised a finger, let it fall, then shook her head. "That made less than zero sense, Pinkie."

Kazuki walked out at a brisk pace. "Miss Pie? Could we borrow you a moment?" I hopped to my hooves and trotted over to him. "Right this way. We have a few questions for you."

Sato was there, seated in a comfy looking chair. "Now, Miss Pie, do you know what a chromosome pair is?"

"Nope." I looked up at one of those magic screens they had, which showed this kinda circular thing with little things inside of it. I wasn't sure what it was.

Kazuki sat in another chair. "All things have a genetic code. Things of the same species have the same amount of 'pairs', basically the number of sections of this code. This code describes how to make that thing. It's the programming language of life."

I still didn't get most of that. "Uh huh?"

Sato pointed at the screen. "Humans have twenty-three pairs. Your blood shows twenty-six."

I pointed at myself. "Well I'm not a human, so that makes sense, right?"

Kazuki grinned triumphantly. "That's what I said."

Sato slapped a hand down on one of the arms of her chair. "This is not a joke! Your blood chemistry is also off. Anything that was comfortable inside you should die in our own systems, and vice versa, and yet here we are, with a pathogen that crosses this racial divide without a concern." She leaned forward and steepled her fingers. "There is one vital piece missing. The others are becoming more like you, are they not?"

I nodded quickly. "Do you think they'll get twenty-six chromo-whatevers?"

Kazuki nodded. "That is the theory. If they are fully being converted to your species, in every way, genetics may be involved, or not. If not, then this is a superficial change, which could result in a variety of long term health issues, since the body would be unable to construct the hormones it needed or maintain homeostasis on its own. If they are, and it doesn't kill them along the way, then they would be horses, entirely. They might even be able to breed!"

Sato frowned at Kazuki lightly. "Try not to sound quite so enthusiastic about that idea."

I put a hoof behind my head. "That all sounds interesting, but what part of that helps my friends stop being sick? I don't want them turning into ponies if they don't want to be ponies." Even if the idea of breeding Emma sounded really good right then. All fat with foal, our foals. She'd be so happy and plump... As I daydreamed, I grew swiftly erect in front of the two scientists.

Sato pointed back out to the hallway. "You can go now, Miss Pie. Thank you."

I snapped back into the present and slunk away. She wasn't much fun at all. I got the idea she was more disgusted than anything else by my display. I didn't mean to show that off to them!

Author's Notes:

So we ended up a 4.5k words, how'd that work out? We need more choices!

1: Pinkie decides to try to bring Aiko over to the happy team and enlists Emma to snug, hug, and possibly much more intimate things with her until she loosens up.

2: Pinkie hurries home to get Homer. Poor dog's locked in their apartment! Surely no trouble will come up in that short distance. She leaves her friends behind for the brief jaunt.

3: Pinkie wants to learn more about the newest pony-to-be. That Hiro guy seems nice enough. Ponies should stick together, right?

4: Perhaps Pinkie's expertise would be best suited helping the scientists. She's seen Twilight do it. How hard could it be?

Vote for your favorite! 2 days to get in your votes, then I get to writing.