I’m immune to fire, unburnable, and unaffected by high temperatures, but standing there in my swimsuit on the beach with the six mares still made my face feel really warm. I was the most clothed out of us, no, I was the only one wearing anything and I was the embarrassed one. Logically, I knew I shouldn’t be feeling like this, but I was anyways. I left the Ember Celica back in the hotel room and my wrists felt weird without them.

We were at a secluded beach, called Diver’s Alcove. It was a small beach surrounded by rocky walls that kept it rather secluded. The water was clear and the waves were low, but still made that nice wavy sound. There was a single pegasus lifeguard stationed here, but according to Twilight, he was actually part of the royal guard. Certainly fooled me.

“Alright Yang, we’re going diving” Twilight said. “I’ll give us all oxygen bubbles and I’ll lead the way.”

“It’ll feel kind of weird, Yang” Applejack said. She didn’t have her hat today. “Having air around your head underwater is just strange.”

“Here’s the bubbles.” Twilight lit her horn and nothing appeared to happen aside from a purple flash around our head. Actually, I was starting to feel a bit more energetic. If it was pure oxygen, well, let’s just hope nobody struck a match. After the bubbles were in place, Twilight signaled the royal lifeguard and started walking into the water.

I was the last of us to go into the water. I walked out further than the mares before I had to dive, and even then, I just let myself slip down under the waves. By reflex, I took a breath before going underwater, even though I didn’t have to.

These air bubbles, while indeed useful, felt a little insulting to me. I wanted to show off my aura goggles and that I could stay underwater for a full minute. Maybe later. At least I knew a few things about how to swim.

We went down to a good depth where the sunlight was streaming in and lighting up the sand on the bottom, a few large rocks, and schools of colorful fish. I took a cautious breath and the bubble stayed in place. No water came through.

“We have to go out about three quarters of a mile before we really have to go down, but it will get easier from there” Twilight said. “Until then, we walk.” She started walking along the ocean floor and four of the other mares walked behind her. Rainbow was apparently a fairly natural swimmer, going through the water as easily as if it were air. Me? I was being dragged down in my walking speed because of my upright stature. After the third time the mares stopped for me to catch up, I decided to change my approach and started swimming alongside them.

The oxygen bubble was an odd experience. It was like a ghostly scuba set around my head. Of course, with my hair extending beyond the bubble, some capillary action took place and my head was getting wet. At least I wasn’t drowning.

Eventually, we reached a cliff, and it looked dark down below it. I could occasionally see what looked like a big screen shimmer occasionally as well over the depths. “Yang, this is where the magic happens. Just swim through the barrier and two minutes later, you’ll be even better equipped for the water.”

“Can you be less vague?”

“But that would ruin the surprise, silly.” Pinkie jumped off the edge of the cliff and dove straight down.

“It is just two minutes” Rainbow said. “It feels weird, but you’ll come out fine.”

“I’ll go last” I said.

“Actually, I need to go last” Twilight said. “The barrier messes with my magic, and I doubt you’d want to drown when the bubble gets cut off.”

“Alright, I’ll go before you, Twilight.”

Rainbow, Fluttershy, Rarity, and Applejack took that as their cues to swim over the ledge and out of sight. After taking a breath to focus, I swam forward and went through the shimmering barrier. Apparently, the strange part would be over in two minutes, so all I had to do was stay calm and let it happen.

The change started out fairly simple. It started by adding gills to my neck, an odd feeling, especially when Twilight took the bubble away and I was breathing and seeing underwater just fine. My hands grew some transparent yellow webbing between the fingers and I was glad I didn’t bring the Ember Celica along, especially since there appeared to be visible blood vessels there.

Then the changes came to my legs. When my feet merged into a single yellow fin, I knew I was becoming a mermaid. As my legs merged upwards, brown scales grew on them, matching my swimsuit.

Speaking of the swimsuit, it was when the changes got there that things went wrong. I didn’t know what was going on, but the pain there was immense, unexpected, and mind wracking. “AAAAAAAAAHHHHHHH!!!!!!!!!!!!”

“Yang?” I barely registered Twilight’s voice as she swam down to me with her rear half still becoming fishy. “What’s wron- oh no. Girls! Get back up here! Yang’s losing blood!”

I managed to look down and saw a red cloud forming around my hips, swirling in the small currents around me. My aura has kept me from getting injured since I’ve been in Equestria, so this was the first time I was bleeding. My breathing accelerated when I saw the blood cloud growing.

Twilight’s horn flashed and Fluttershy hugged me, though the hug didn’t help with my breathing.

“We have to get her back to the beach before the sharks get to us” Twilight said. “I’ll explain what’s happening later.”

The mares formed a pod around me and they began swimming at high speed through the water with me in tow. The speed they were going at sent water down my swimsuit, causing me to scream more and weakly thrash in their grasp.

Before I knew it, we were back on the shore and the changes were undoing themselves. I was already starting to feel my legs again as they reformed and split apart. The webbing on my hands withdrew, the gills vanished, and any other changes I didn’t notice undid themselves as well.

I was feeling weak and tired, so I closed my eyes.

“So, what happened, Twilight?” Rainbow asked. “Why would that happen to Yang when it’s never happened to us?”

“The swimsuit is ruined!” Rarity exclaimed. The area around Yang’s hips was dark, stained by her own blood, which was also running down her thighs. “Well, it can be cleaned, and nothing’s torn, but it’s still ruined!”

Twilight returned as the lifeguard flew off. “He’s off to get extra help. So, here’s what’s happened, girls: the magic that turns us into merponies was working just fine on Yang. There was no bad or abnormal reaction there. However, because of the swimsuit, the change couldn’t finish. This left Yang with exposed nerves right on the swimsuit, so every time it moved even a bit, it would hurt her. It also kept her spine from fully connecting, leaving her tail limp and immobile. The exposed spine also contributed to her pain. As for the bleeding, that had two factors, both with the swimsuit: the first was that the swimsuit kept a number of blood vessels from properly forming, leaving them open. The other factor was how the swimsuit draws liquids away from the wearer, including blood. When Yang began panicking, that increased her heart rate and blood loss.”

“Will she be fine?” Fluttershy asked.

Twilight’s horn flashed again. “She has just enough blood to stay alive, and she’s not bleeding anymore.”

“Can’t we just give her some blood?” Rainbow asked.

“No. Her aura would keep the needle from going in, and there’s no human blood we can use anyways. All we can do is get her out of here, clean her up, and watch over her as she recovers. Fluttershy, can you come up with a diet to maximize her blood recovery?”

“I’ll do that” Fluttershy said, a rare steely determination in her voice.

“I’ll help her” Pinkie offered.

“Rainbow, can you go back down there and tell Queen Novo and Princess Skystar what happened?” Twilight asked.

“Flash dry me, and I’ll fly out and dive down” Rainbow said.

“Done.” Twilight’s horn flashed and Rainbow’s fur and feathers were dry.

“I’ll stay down there until I hear back from you. Keep me updated.” Twilight had barely nodded when Rainbow took off and flew over the water before taking a deep breath, closing her eyes, and going down.

“Rarity, you know her clothes better than any of us, so you’re in charge of that.”

“Of course, dear” Rarity said.

“Applejack, can you run support for the rest of us?”

“Ah can do that” Applejack reported with a salute.

“Thanks. Ah, here’s the rescue.”

Four pegasi pulling a long carriage came in fast and landed on the beach. The side of the carriage opened into a ramp and three unicorn doctors came out. “Ah, Princess Twilight. Can you tell us anything about what happened?”

“Yang lost a lot of blood when her swimsuit interfered with a spell. Fortunately, the spell’s been reversed and she’s no longer bleeding, but she’s out cold. Speaking of which.” Twilight cast another spell on Yang and found out what she needed. “Her temperature’s just fine.”

The unicorns levitated Yang up and put her on a gurney. “So what do we need to do?”

“Since she’s not injured, all she really needs is to be cleaned off and checked for anything else.” A flash of purple later and a folder was in Twilight’s levitation. “Here’s the vitals and information I have on her.” Before giving the folder to the paramedic, Twilight made a note about not trying a blood transfusion and why.

“Thank you. We’re taking her to the Los Pegasus hospital and, assuming all she needs is some rest, we’ll be able to discharge her shortly after she wakes up.”

“Thanks.”

After the unicorns got Yang into the carriage with them, they closed it and they took off.

“Before anypony says anything, let me channel my inner Dashie” Pinkie proclaimed before rummaging through her mane. After a moment, she pulled out a wig that looked exactly like Rainbow’s rainbow mane and fit it over her own and cleared her throat. “What are we going to do now? Skystar wants to see Yang, Yang can’t wear a swimsuit down there because it messes with the transformation, and Yang won’t even go outside without any clothes on.”

“Funny you should ask, Dashie” Rarity said. “You see, I actually made a bikini for Yang when I made her swimsuit, and I thought I’d try to talk her into at least trying it on for me while we were here. We can have her wear it down there, and before she goes down, she can take the lower half off. Since the conflicting area appeared to be only in the hips, she should be fine.”

“But what about the piece that’s taken off? What’s going to be done with that? She wouldn’t want to lose it.”

“I can find a cinch pouch she can tie to her arm. Shouldn’t be more than five bits.”

“Alright” Twilight said, happy with the plan that was concocted. “I’ll teleport us to the hotel and we can do our things from there.” In a flash of purple light, the five mares vanished, leaving only the royal lifeguard there. Once the stallion was sure he was alone, he pulled out a scroll to write out what happened so Celestia could know. When he was done with that, he pulled out another scroll and wrote a haiku.

Author's Notes:

Well, that got messy.