Rose Collins (Cariba Heine) has had the world pulled out from under her feet after losing her mother and younger brother. For six years all she wants to do is scowl and ignore everyone. She wants nothing to do with life. Her attitude is seriously starting to bug her older sister Lily (Claire Holt) and her friend Lewis Williams (Angus McLaren). Rose has no idea what Lily and Lewis have given up for her in order to see just the smallest bit of progress. They don't of course, and Rose remains oblivous. Still, life goes on.
Till James Wood (Burgess Abernathy) comes to town. James is the opposite of the quiet world Rose inhabbits and Rose has to admit that even if his is constantly leaving red roses around and annoying her, she might just have the smallest crush on him.
But James has a secret. It seems that everyone does, as Lily and Rose are mermaids, Lewis and Lily know something Rose doesn't, James's sister Constance (Phoebe Tonkin) is far to shy to be his sister--and who is this guy who calls himself "Ash" but looks like that guy from "Legend of the Seeker?" And why does Lewis hate him so much just because he's dating Lily? It turns out Ash has a secret he doesn't want Rose to know also. And why does James freak out when Rose borrows something from Lily? Rose doesn't know who to trust anymore and with her head spining at about a thousand miles and hour she'll have to confront her sister, attend a vampire ball, and much more before she really starts to see the big picture.
Another average day in the life of a teenage mermaid.