Amy calls her mom up to tell her that she's going for a quick swim in the ocean. Shortly after she dives in, a thunderstorm begins, and she takes shelter in a cave. As she worries about how she'll get home, she's abruptly trapped under a waterfall.
Now asleep on her couch, Amy is woken up by her phone ringing. Still bleary, she goes to get herself a drink, but spills water on herself. Trying to dry herself off with a damp towel, she abruptly transforms into a mermaid. Alarmed, she declares herself a "mer-freak."