It's the school holidays, but the fashion fairy princesses are feeling glum. They're missing Rosa, who has gone to stay with her cousin Princess Honey on Shimmer Island. Then a hummingbird flies through the castle window carrying an important message. The fashion fairy princesses have been invited to join Rosa and Honey for a holiday! They excitedly pack their suitcases with the perfect summer outfits, and then board the palace's royal butterflies to make the journey. From high above the clouds they get their first glimpse of Shimmer Island, a crescent-moon-shaped slice of paradise. The fashion fairies princesses are happy to be reunited, and Honey takes them on a tour of the island, pointing out her family's majestic sand castle, the enchanted waterfall and finally the pool, where they relax on lily pads. Then it's time for the welcome party which the islanders are throwing for the princesses. They wear flower garlands around their necks and dance to the music of the shell drums. The next day the fairies wake to find the island in uproar. The reserve bottles of sunshine that are stored behind the waterfall are missing! The fairies are determined to find the culprit, and soon trace the stolen sunlight to a grumpy old sand fairy. Can they cheer her up and get the sunshine back?