Twilight reached back and casually flicked the lock on the door. Science did not like being interrupted, after all. "We'll start with a basic examination. If you would kindly disrobe and lay on one of the tables, we'll begin."
She advanced towards Indie as he sat down nervously. "Don't worry. This will be completely non-invasive."
A knocking on the door interrupted the flow of things and Twilight frowned at it. "What?"
"Twilight?" It was Sunset. "Do you have the new kid?"
Twilight blinked in surprise. How? So fast?! She moved for the door and unlocked it, allowing Sunset in.
"Hey Tw-- Oh! Are you Indie?"
Indie waved at Sunset energetically. "Hello there!"
Sunset wriggled a few fingers and looked back to Twilight. "Why do you have him locked in here?"
Twilight opened her mouth, a dense explanation ready.
"Nevermind. You know the girls are looking for him, right?" Sunset cocked a brow then looked to Indie. "Your friends are wandering the school looking for you."
Indie hurried to the door as if he could spot his friends. "Are they? They're here?!" A pause. "Do they look like us?"
Sunset smiled as she followed after him. "They do, now let's get all three of you back together."
Twilight gave a faint pout as the science was dashed. "Can't I at least perform a basic examination?"
Sunset shook her head. "Why? He's a human, just like the sirens, and Twilight, er, the other Twilight."
Twilight wriggled a few fingers at Indie. "There are countless ways it could vary. Without a thorough examination and a few other tests, we'll never know. Pony-Twilight will never consent to letting me give her the full battery."
Sunset cocked a brow. "So you decided to take advantage of the boy here? Come on, he barely knows where he is."
"Canterlot High?" ventured Indigo. "Can we go to my friends?"
Twilight let a sigh loose. "Fine. Maybe after they're reunited, they'll be amenable to furthering science." She flashed a hopeful smile. "Do you know where they are now, Sunset?"
Sunset pointed one of her wriggly things at the door she entered from. "I had them wait for us in the band room while I had a look around so we wouldn't lose each other. I had a good feeling I'd find you here." She leaned forward. "Science girl."
Twilight flushed a little. "Aren't you curious?"
"Of course I am." Sunset turned to Indigo. "But we have to be good to friends, new and old, before that. Indigo, Indie, right? Sunset. Nice to meet you." She offered her wriggly claws towards him and he raised his, bumping against her. She smirked at the exchange. "Not quite the handshake I was expecting." She took ahold of his and showed how to grip and shake properly. "Now let's get you back to your friends."
Twilight moved to repeat the gesture. "And I'm Twilight, nice to meet you. Please don't be angry at me. I really just wanted to look..."
Indigo didn't have it in him to be upset at the female, uh, whatever she was. "It's alright. Let's get to my friends and we can decide what to do after that."
Smiles were exchanged. Forgiveness was given. Soon they were moving through the hallways and down stairs until they arrived at a room where four more... whatever they weres, were waiting for him. Two of them broke into smiles. One of them had a familiar hat and jewelry in her mane. "Indie!"
"Cherry?" His eyes darted to the female beside her. "Berry?"
"My Indigo!" Berry rushed up and embraced him tightly, forcing the breath from him.
Applejack shook her head a little. "Good to see them back together. Where'd you find him, Sunset?"
Sunset hiked a thumb at Twilight who was just behind her. "He was with Twilight, as you suspected. Miss Science here was ready to do a full exam."
Twilight huffed softly. "I was just looking..."
Suddenly Berry was invading her personal space. "You had better not have hurt my Indie!"
Indie pulled her away. "I'm alright! Miss Twilight didn't do anything bad."
Cherry smiled brightly. "Well we're all together, and nopony got hurt, that's good. I guess we should head back..."
Rainbow rolled a hand. "Before or after you show me some awesome swimming moves?"
Twilight grinned hopefully. "And I get to do a little examination?"
With hesitant noises from Applejack and Sunset on their way, the group ended up visiting the pool-side. Cherry and Berry shed the clothes over their swimsuits and Rainbow clapped her hands in giddy expectation. "Alright! Let's see how you do!"
Applejack rolled her eyes. "One lap, then they can get on back through the portal before something happens."
Rainbow waved it off. "Yeah yeah yeah. There are no world-consuming monsters involved this time, so we can enjoy ourselves. Go on in, the water's fine."
Cherry decided to be the first one in and dove in, slipping into the water like the dolphin-creature she was born as and barely making a splash. She emerged to see the line of them staring at her as if she had grown a second head. "What?" That's when she felt it. She didn't have legs. She had her wonderful, wonderful tail back. She looked down at the tail in the water and giggled with joy, sinking back into the water and darting off with amazing speed.
Berry suddenly jumped in, soon re-tailed and zipping off after Cherry.
Rainbow clapped her hands. "Look at 'em go!"
Applejack shook her head. "Did you know that was going to happen?"
"No, but it's awesome! Wait a second, let me get my suit on and I'll see how I do against them." She dashed off to the locker room.
Twilight looked like she was about to hyperventilate from the possibilities. Sunset rest a hand on Twilight's shoulder. "Take it easy girl."
"Easy!?" She spun to face Sunset while gesturing at the mer-maids in the pool. "Look at them! The implications! Please tell me I can examine them now."
Indie raised a hand cautiously. "You can look at me?"
Rainbow came dashing back, almost slipping on the slick surface before she jumped in the pool to join the other two. "Just because you have flippers doesn't mean you're the fastest!"
Cherry tilted her head at the human. "I think it does."
Berry shrugged. "My rival isn't often right, but she is this time. You don't have a chance."
Twilight pointed down into the waters. "Does it have the same effect on you? Please confirm."
Indie sank beside the pool and reached out with a hand to swish through the water, nothing happened. "Maybe I have to be in the water..."
Applejack shook her head. "We don't have a boys' swimming trunks."
"Alright." Indie stepped into the pool without warning, sinking into the depths even as his legs became a powerful tail. The metal pants became goofy-looking metal legs that held themselves close to his body. He surfaced, tail thrashing gently and holding him in place despite the weight of the metal. "There." His shirt was entirely soaked, as was any other clothing that hadn't absorbed into his changed body. "Now what, Twilight?"
While Twilight giddily began taking notes, Rainbow and the two sea mares lined up on one side of the pol. "One lap," declares Rainbow, pointing to the other side. "There and back. Ready?" Cherry and Berry nodded, then they all took off.
Sunset let out a sigh and turned away, only to see a person she had been hoping not to see, Vice-Principal Luna. "Oh... hi?"
Luna raised a brow. "Please tell me there are no magical... incidents we should be made aware of, and explain why none of you are in class."
Applejack gestured at the others, making scientific notes and racing in the pool. "We done had some visitors, and, uh, they got a little carried away. If it helps, they're pretty friendly."
Luna nodded at that. "I'm glad to hear that, but these are school hours. Say goodbye to your friends and get back to class." Any other student caught playing hookie might have gotten detention, but she couldn't be sure if their presence spared the school from calamity. "Thank you."
Rainbow Dash lost the race, but not for lack of effort, and not without having a grand time in the attempt. She reached the end to be cheered on by the two who proved to be good sports about the whole thing.
Twilight got some notes, even if she didn't get all the notes she wanted, as if there was such a thing as 'enough' notes.
Ultimately, it was time for all the ponies to go home. Once out of the pool, they became 'normal' humans again and could walk back to where the portal waited for them in the statue.
Applejack tipped her head. "You tell Twilight we send our regards, y'hear?"
Cherry bobbed her head. "We will! It was nice meeting you all."
Berry nodded in agreement. "Maybe next time we can visit without the drama in the way." She offered a hand towards Rainbow. "Keep practicing, maybe next time you'll win."
Rainbow smirked, knowing when she was being patronized. She accepted the hand and gave it a firm shake. "Next time, we race on land. See how good you are there."
Twilight bowed to them all. "Thank you for what examination I did manage. Have a safe trip home."
Sunset gently shepherded the seaponies back towards Equestria. "Go on. This isn't your world. But if you do stop by, we'll be here for you, promise."
With a chorus of goodbyes, the three vanished into the portal, sent hurtling back to Equestria. Cherry landed first, standing on all fours a moment before Berry crashed into her and sent them both sliding. Indie came through last and landed upright. "Twilight, there you are. You're much prettier as a pony."
Twilight blinked softly. "I gather you met my double then?" She pulled the lever and turned off the portal. "Is everypony alright?"
Rainbow flashed a wide grin. "Was she half as cool as I am?"
Berry climbed off her rival and rose to her own hooves. "Hey, Rainbow?"
"Yeah?"
"Wanna race?"
Berry and Rainbow took off, apparently meaning to make good on the challenge straight away.
Applejack chuckled softly at the antics. "Well, ah guess nothing too bad happened?"
Cherry nodded as she shook out. "Your friends were very nice to us. That other dry world is a fascinating place. Can we visit again in the future?"
Twilight paled a little at the idea. "Oh, right. Your parts arrived."
That was enough to make Cherry's mind move from the portal entirely as she wandered off to see her train parts.
Indigo was the last seapony in the room. "The other you was very curious about how things work."
Rarity glanced at Twilight. "I suppose some things are true no matter the world."