Welcome to Lady Sealia Foam’s Mermaid School! Here you will learn siren songs, proper care of sea creatures and how to not fall off your seahorse.

It is Marnie Blue's very first day at Lady Sealia Foam’s Mermaid School, and she's terrified. What if she can't make any new friends, or if she's asked to ride a seahorse? What's more, her famous diva aunt Christabel was a notorious rebel at the same school, and got up to all sorts of naughtiness. Marnie is soon branded a troublemaker by her grumpy octopus music teacher and wants nothing more than to clam up. But when a fellow pupil finds herself in danger, it's up to Marnie to show that daring runs in the family and swim to the rescue.