The Search For WondLa is a combination of fantasy and science fiction. This book is huge -- over 450 pages -- so it might seem inappropriate for middle grade kids. However many of the pages are illustrations by the author and, like the Harry Potter books, it carries the readers into a fantastic world they won't want to leave. The characters and situations are extremely creative and different from the standard sci-fi or fantasy ones.
The story is about a girl, Eva Nine, who has grown up under the care of a robot and has never seen another living being. (It's interesting that her name is similar to the first woman in the Bible.) She's flung into an exciting adventure in a world filled with fantastic creatures, both good and evil. More than anything she wants to know where she came from and to meet other human beings - assuming she can survive long enough to do that. I cared about Eva and was eager to find out what happened to her.
Many series books leave the reader hanging at the end and they must read the next book, and the next, etc. to find out what happens. Personally, I consider that dishonest and never read a second book by an author who writes like that. However Diterlizzi is honest. The plot of this book is resolved in a satisfactory way, but the reader is left wanting to know more. I can't wait to read the next book in this series.