Isadora and her family go on holiday and disaster strikes when Isadora accidentally loses dad's treasured comb. She meets a mermaid called Adelina who knows where it is. So Isadora shapeshifts into a mermaid to search under the sea.
When Isadora is invited to a sleepover at the Mermaid Palace with Princess Delphina she is super excited. They have a wonderful time together but when it's time for bed Isadora starts to feel a little homesick.
Granny and Grandpa Moon are babysitting Isadora and her sister Honeyblossom. Isadora cheekily fibs and assures Granny and Grandpa that they are both allowed loads of fairy nectar on their strawberries. It soon becomes evident they aren't.
It's the spring ritual of "Hunt The Bluebell"- the first to find a bluebell is crowned the winner. But Mirabelle is discovered bending the rules by using magic potion, Isadora is determined to help her cousin Primrose win.
Isadora and Primrose and Aunt Crystal go on a trip to the Land of Snow and Ice to fly on snow dragons and to see the Aurora Borealis. They discover a dragon's egg that needs to be rescued and taken to the mountaintop to hatch.