When Emerald and her stepsister, Delphina, sneak out of the palace in search of sea sprites they know it isn't strictly 'perfect mermaid princess' behaviour. But they're about to learn that being a mermaid princess is about more than just following the rules - it's also about following your heart.

When Emerald and her stepsister, Delphina, sneak out of the palace in search of sea sprites they know it isn't strictly 'perfect mermaid princess' behaviour. But they're about to learn that being a mermaid princess is about more than just following the rules - it's also about following your heart.