There is a powerful tropical storm, and giant waves are crashing onto Mystic Island in the middle of the sea. A large ship is torn apart by the huge storm, and items from the ship start washing up on the beach of the magical island. Mystic the mermaid lives on the island along with three other mermaids. After the storm, Mystic finds and rescues a little baby girl from the sea. She names the baby girl Ava and raises her on the island. Mystic Island is very beautiful and full of all different kinds of tropical fruit trees, birds and animals. There are more mermaids that live on a nearby island called Sea Snake Island. A large volcano that has not been active for over a hundred years starts rumbling on Sea Snake Island. Take a deep breath, and go on a fun and exciting underwater adventure in the middle of the sea. Children learn all about the awesome creatures of the sea. There are some activity games at the end of the book.