Eve and the Mermaid's Tears: Keeper of the Crystals #3

Eve and Oscar find themselves in a world where cut throat pirates rule the waves and where the language of the sea is the only tongue spoken. Its the mermaids who need help. Theyre being captured so that their tears can be sold as treasure. But if these protectors of the ocean disappear then the balance of the ocean is upset and all marine life is under threat. Can Eve and Oscar find their sea legs and help the mermaids?