"Well, there is an entire ocean for us to explore." Millie answered. "Maybe you could show us around?"
"That sounds like an idea!" Corey says enthusiastically.
"A wonderful idea." Lorelei said.
"We'll even show you some hidden wonders only we mermaids know of." Nina added.
"Oooh, I can't wait!" Corey squealed. With that, the mermaids dove down beneath the water, followed by the two temporary mermaids, who took a deep breath before diving after the others.
Kelly met them and observed the rather awkward way they flailed their tails around. In a voice that possessed an ethereal echo, possibly from how sound carries in water, she said. "No, no. Watch me." She slowly swam back and forth, undulating her tail before stopping before them. "See? These aren't fused legs, it's a tail; an extension of your spine." She saw the two girls' puffed cheeks. "Oh, by the way..." She clapped her hands on their cheeks, forcing bubbles out of their mouths. "...your mermaids, for now. There's no need to worry about drowning."
Millie and Corey gave each other a look, then spat out the air they've stored at Kelly, who giggled as she swatted the bubbles away. They then took a deep breath, the seawater filled their lungs completely before they slowly exhaled. "Oh, wow!" They said simultaneously. "Your voice!" they said to each other, noticing that theirs, too, possessed an ethereal tone.
"C'mon; time's a-wastin'!" Polly shouted. Milley and Corey, now better able to use their tails, followed Kelly to the rest of the mermaids.
Polly's comment made Corey wonder. "How long will we remain mermaids, anyway?" She asked.
"The spell lasts about a day," Barbara answered, "Or, if you climb onto land and your tail dries out; whichever comes first."
"It won't be sudden, though." Loreli said. "If you're underwater as the spell wanes, then your tail will start to feel stiff and water will become harder to breathe." That will be our cue to return you to the surface.
"Sounds good to me!" Millie said.
"I don't plan on losing this tail any sooner than I have to." Corey commented.
As the mermaids swam along, Millie snuck glances of Corey, who was completely enthralled with her temporary form. Millie herself was quite taken with her new state as well, but somehow, Corey seemed somehow more intriguing than she used to be; how the filtered moonlight shone off her tail, the echo of her voice as she laughed, it somehow made her think of the kiss Lorelei gave her, but with Corey in Lorelei's place.
Corey suddenly looked over at Millie. She immediately turned to face forward, blushing. Her heart pounded in her chest.