Twin sisters Ellie and Clare discover the secret of a lifetime... That their royal bloodlined mermaids, hidden from them for 15 years, to top it all off they are the mermaids of a 200 year old prophecy. Having a whole year to learn everything they were supposed to be taught as merlings, while trying to save the world. And being hunted by mermaid bounty hunters, Zeena a fellow bounty hunter taking them. Yet she helps them not wanting anything to do with her family and their job, Zeena knowing that if she does this she'll never be accepted into her family or bounty hunter lifestyle. While on this journey we meet a merman which is the last thing Ellie needs, having a previous history with him just to complicate things. Their grammy having to be thrust back into this society and mer lifestyle for a second time, something she purposely let go of.
3 parts