"What's a fairy to do? Jack Frost has stolen three enchanted pearls that control the magic of the oceans. Now the tides are all wrong, the sea creatures are confused, and even daytime and nighttime have gotten mixed up! When Shannon the Ocean Fairy asks Rachel and Kirsty for help, they set off on a magical adventure to an underwater world. But will they find the pearls in time ... or will the girls be lost at sea?"--p.  of cover.