Fluttershy, Twilight and Rarity reached the part of the bay where Rainbow Dash escaped. Much to their horror, they saw that Rainbow Dash had already propagated the mermaid curse. Twilight was thinking fast, she knew everything was her fault because she mingled the portal in first place. She had wanted to alter the species-adaptive properties of the portal between Equestria and Earth, to allow her to explore Earth in her alicorn form, and her friends explore Equestria in their human forms, and also allow to find her friends and open portals on demand, not bound to the statue at Canterlot High. It all ended up malfunctioning. The portal made Twilight appear not on Canterlot city, but thousands of kilometers to the south, where her friends were vacationing. At least the spatial-following function worked. The magic still worked as intended originally, adapting the user’s body to the best suitable biology compatible with the environment of the destination. It turned out that the portal opened beneath the water, and so Twilight was transformed into a mermaid. But, instead of making the change stable and permanent (just like Sunset Shimmer’s human form is permanent and stable while living in the human world) the magic of the portal was now lingering and becoming contagious by touch. Twilight accidentally transformed Pinkie Pie into a mermaid, who then touched Rainbow Dash and became one in turn, then Rarity was transformed by Rainbow Dash, then Applejack… then Fluttershy… now, the chain of propagation of the mermaid curse reached Trixie, whom was transformed by Rainbow Dash. Trixie was now happily in the process of turning her friends Lavender Lace and Fuchsia Blush into mermaids. Lavender was already transformed and was frolickingly swimming and testing her new tail, while Fuchsia was all too happy, about to touch Trixie and receive the “gift”.

“Trixie! Stop it right there!” yelled Twilight Sparkle, as she came to a stop, together with Fluttershy and Rarity, who were assuming now their best “mean-girl-absolutely serious” poses. They looked adorkable more than serious, though.
“Rainbow Dash! Come here this instant!” said Fluttershy, as she put on her best “Flutter-Stare™” expression.
“You all need to stop this madness!” said Rarity, pointing a finger at the trio of girls. “And Rainbow… you… owe me…” continued the fashionista-turned-mermaid.
“Yeah? Why? The Great and Powerful Trixie finally has access to bona-fide Equestrian Magic! Trixie nor her friends will lose the chance to be truly magical! You have all been so greedy, keeping all this power to yourselves! Playing super-hero and Magical-Madoka-Girl-Squad, while Trixie had to buy new illusionism books!” said Trixie, her friend Fuchsia mere centimeters from touching her.
“Yes! We now all feel so good! It is wonderful to feel the magic… to breath underwater…. I feel…. unique and free!” said Lavender, all to excited with her species change, swimming around and floating in reverse

“Yeah, I bet… it is all fun and games until you know that this could be PERMANENT! I truly hope you apes enjoy sleeping with the fishes, because not even I know exactly how this happened!” affirmed Twilight, crossing her arms, conveying seriousness and a bit of disdain. No matter which universe she was, Trixie only understood rough, she thought.

“I see…” said Trixie, her expression becoming funny as Fuchsia closed her hand around her blue wrist.
Maybe she was fulfilling her childhood fantasy, maybe she wanted to leave her boring life behind, maybe she wanted to have a little fun for a long time, the fact is that Fuchsia took the decision to join the ocean ladies. Her expression became funny, too, as she felt the electrifying magic flood her body and execute changes into her respiratory system.