The book consists of two completely different plotlines that kind of converge in the end with "kind of" being the key word. Plotline 1:
Dorothy finally realized it would be a good idea to bring her aunt and uncle to the Land of Oz. She was made a princess of that land several books ago, but waited for a while before realizing it might
be a good idea to bring her only living relatives to the magic place. Actually she waited until her uncle's health became so bad he could not work on his farm anymore. For this reason I would call Dorothy to be a little slow in the mental department, even considering her age.
This part was amusing at times and the new creatures encountered by Dorothy and her adoptive parents were highly imaginative and amusing. Dorothy's favorite pastime is to get lost and end up in the Land of Oz and here is no exception. This time she manage to get lost in Oz itself.
By the way it might look cute, but the episode where she ended up hungry in a country of living gingerbread and insisted to eat some of its inhabitants stroke me as very disturbing.Plotline 2:
The Nome King who was put to shame in front of his subjects by Dorothy and Co. in one of the previous books decided to take his revenge upon the inhabitants of the land of Oz. He enlisted some evil creatures to aid him and found the way to cross the impassable desert which separates Oz from the rest of the world.
This one had so much potential, all wasted in the end. The beloved rules of Oz, princess Ozma did not even try to resist the invaders knowing in advance they would kill her mortal subjects and make slaves out of the immortal ones. Nice care for the people who adore her, by the way.
This part was resolved by a heavy use of a typical Deux Ex Machina in the very end.
L. Frank Baum wanted to finish the series with this book and it is very clearly shows here; we all know that he changed his mind later and wrote many more of the books of the series. The only reason I rated this one with 3 stars instead of more deserved 2 is the fact that I read the book twice. I did my reread to refresh my memory for the review and for the next book (I only read first six the first time around).