OK, spoilers time as I give a quick summary of the plot.
Dorothy, on her way back from Australia, is visiting some relatives in California. And earthquake opens up the world beneath her feet. Okay, under the buggy she is riding in. Dorothy, her cousin Zeb, the horse Jim and Dorothy's kitten Eureka all end up falling into the magical kingdoms under the Earth.
Shortly thereafter, the wizard shows up in a balloon that had ALSO fallen through a crack in the Earth from ANOTHER Earthquake. Seriously, coincidence in the eyes books is more reliable than gravity. Lightning doesn't just strike twice, you could set your a clock by it.
At this point, our heroic little band ends up visiting a series of magical kingdom's, practically turning into a road trip movie. However, unlike some of the later books, there is some thematic progression in their travels, with each one more dangerous than the last.
They start off in a glass city of the heartless vegetable people. They passed through a beautiful valley filled with ferocious, invisible bears.
After a breather scene where they meet the silly Braided Man, our heroes end up in the silent, wooden kingdom of the gargoyles. The gargoyles might actually be one of Baum's most disturbing creations, not the least because they completely silent and relentless.
The gargoyles are followed up by a nest of baby dragons who really, really want to eat our heroes.However, they do have some amusing dialogue so they're not nearly as creepy as the gargoyles.
Once our heroes get past baby dragons, they come to the end of their line and are well and truly trapped. Fortunately, Ozma regularly checks on Dorothy magically and uses the power of the Nome King's magic belt to transport the mole safely to us. As I mentioned in Ozma of Oz, that belt is the ultimate deuce ex mechana of the books.
After that, everyone has some fun times in Oz. It is worth noting that Jim and Zeb and Eureka actually all decide they don't want to stay in Oz. The wizard, of course, does decide to stay. And Dorothy goes back home as well.
After the first three books in the series have such different tones, the fact that Dorothy and the Wizard in Oz is written in the same tone as Ozma of Oz actually makes it harder for me to say anything that is trying to be deep about the series.
As I already mentioned, the book is really serious with episodes, with the heroes passing through different magical kingdoms. This is something that happens a lot in the Oz books.
However, Dorothy and the Wizard in Oz actually has a bit more of a framework to its road movie feel. For one thing, unlike most of the books, virtually every place that they visit wants to kill them. With the exception of their visit to the Braided an, every place is actively out to get them. And, as they go farther and farther under the Earth, each place becomes progressively more dangerous.
I am also going to go out on a limb and say that this book has some of the most violent scenes in the entire series. The first book in the series is also pretty violent but I found the violence in this book more striking. And the wizard is central to almost all of the violence.
His duel with the vegetable wizard, which begins with parlor tricks, rapidly degenerates to the two of them trying to kill each other. The wizard comes out ahead by pulling out a sword and. Cutting. Him. In. Half. Really, that is some rough stuff.
The wizard also kills one of the invisible bears with his sword and, when they get to the land of the gargoyles, pulls out a pair of revolvers from his magical trick bag to fight off the gargoyles.
Seriously, for his magic tricks at the fair, the wizard is carrying around a fully functional sword and two loaded pistols. What, in the name of organized crime, kind of carnival was he working at?
The development of the wizard throughout the early books is a fairly interesting one. Of course, in the original wonderful Wizard of Oz, he is a harmless and lovable trickster. However, in the stage play, he is the big bad guy and that gets reflected in the Land of Oz, where he had a hand in kidnapping and transforming of Ozma.
But all of the children who just read the books really liked the lovable old humbug and wanted him back. So with this book, we completely forget about him aiding and abetting in the kidnapping of a small child. Although, if that bugs you too much, Mombi could have been lying about how complicit he was with the kidnapping.
From here on out, the wizard is going to be a regular character in the books and he is going to be practically a surrogate father figure for all the small children who end up living in Oz.
Unusually enough, almost none of the new characters who get introduced this book really go on play a major role or even just hanging out in the background of Ozma's court. Jim and Zeb are never mentioned ever again. And, while Eureka the kitten does eventually make it back to Oz, she never returns to any degree of prominence. The glass cat who is introduced a few books later is the definitive cat character in Baum's Oz.
And, quite frankly, the pet piglets of the wizard makes such a small impression that I haven't even bothered to mention them up until this point.
While I liked Ozma of Oz better, Dorothy in the Wizard of Oz is still a strong part of the canon. The characters are constantly in dire danger and that keeps the story driving forward.
It is a book that I would recommend reading yourself before you would read it to a small child because some of the scenes of violence are pretty shocking compared to what leads up to them. While they aren't graphics or glory, I still think they are startling. And you wouldn't have to change the gargoyles at all to make them at home in a horror movie.
Still, if you have decided to read the first three books, you won't be disappointed with the fourth.