I think that Gregory Maguire has saved his best for last. His fourth and final book in the Wicked Years saga, Out of Oz may be my favorite. Pitched against the backdrop of war, Maguire brings back many favorites to conclude the series. The story centers around Elphaba’s granddaughter as she matures and faces the consequences of her ancestors’ actions. Even Dorothy make a return visit to Oz.
Out of Oz is not nearly as edgy as Wicked, but may be a better tale and I often found myself glued to its pages. While I think you could enjoy the book even if you hadn’t read the others, it would be a much richer experience if you have the others as background. It would also benefit you to have seen The Wizard of Oz movie a few times as Maguire sneaks many references to the classic movie.