Aziza is excitedly packing her suitcase ready to go on holiday when she finds sand and seashells from the fairy door all over her room! Before long, she is stepping through the door and out onto Shimmerton’s beach, where naughty fairies, the Gigglers, are causing havoc by accidentally awakening an ancient shell-walker who has been asleep for many years under the sand.

Everyone scatters as the shell-walker grows bigger and bigger. What can be done? Aziza’s new mermaid friend might just know someone who could help.