Marina has just moved to Mermaids Rock and is thrilled to make friends right away. She and her friends soon face a mystery when the coral caves nearby are damaged. But who--or what--could have caused the destruction? Marina is new in Mermaids Rock. She has traveled the world with her scientist dad, and she can't wait to settle down and make friends! She meets some mermaids who love animals and the environment as much as she does. Soon, the group faces...