Echo's Lucky Charm (Dolphin School #2)

Pearl and her friends Echo, Splash, and Flip are preparing for their first test at dolphin school! It's in Magic class, which is Echo's best subject, so she's helping them study. But then Echo loses her lucky shell necklace. She's very upset -- and, even worse, she's barely able to do any magic! Can Pearl and her friends help Echo find her necklace and regain her skills before their big test?