*But what if you didn't? What if you Dive into the Pond instead?

Before going through the waterfall, you want to be sure to check everything, So you decide to dive into the pond, to see if there's a hidden switch or passage on the bottom.

You inhale, and dive into the pond. As you're about to reach the bottom however, you realize the pond is deeper than you expected, and you're already running out of air. Panicking, you abandon the search, and begin returning to the surface. Unfortunately, your lungs give out, and you take in a large inhale of water.

You begin to panic even more, afraid of drowning, but as you swim upwards, still a distance from the surface, you realize something. You can breathe! You don't know how, but you can. As you continue swimming to the surface, your legs cramp, as they seem to be pushing together by some unknown ****. Not knowing what's going on, you continue your swim to the surface, and as you do, something long and flowing covers your face, but you pay it no mind, as you know you're close to the surface, and you can figure it out when you're on dry land. You don't even stop when you begin to feel a tingling on your chest and face.

Finally, you breach the surface, and swim over to the pathway you neglected to use before. Once there, you lift yourself onto the shore, and discover something Surprising!

https://www.deviantart.com/sorawolf7/art/PrimarinAsh-643159490

You've Turned into a Mermaid! (Well, Humanoid Primarina)

Epilogue: You Try to stand, but quickly realize that your legs (or you guess Tail would be the more Accurate term now) can't support your weight, and you can't exactly crawl everywhere, so you reluctantly return to the pond, where you spend the rest of your life, swimming and singing for the entertainment of your captors. Over time, you get used to, and even begin to enjoy, this new life of yours, but you can't help but miss your old life, and friends.