While it is far from the worst book in the Oz canon, the Road to Oz might have the most banal plot out of all of them. Dorothy, Toto and assorted companions end up on a magic road so they can go to Ozma's birthday party, with Ozma keeping an eye on them the whole time.
Don't be me wrong. The book is a fun read. It introduces several important characters to the series. And, for me personally, inspired me to read other books by Baum. But every other book has some kind of crisis going on while the Road to Oz is just an invitation to a party.
Let me spoil the plot for you.
After meeting the Shaggy Man, who is basically a slightly insane homeless man with a magical artifact, Dorothy and Toto find themselves somehow warped from Kansas to a road that passes through various magical kingdoms. Quite a change from a cyclone!
I have to say, reading this book as an adult and as a parent, the Shaggy Man actually starts off pretty creepy. He shoved Toto in his pocket when the dog growls at him before he meets Dorothy. Then, he insists Dorothy go off alone with him to show him which way to go. Seriously, if this wasn't a happy, innocent Oz book, we'd be talking hardcore stranger danger material. Fortunately, it is an Oz book and the Shaggy Man turns out it to be a capital fellow.
They basically just run into Button Bright, a simple boy from Philadelphia, and Polychrome, the rainbow's daughter, who round out the group. To be fair, Dorothy usually does just randomly run into people who will become staunch friends.
They pass through a town of talking foxes and then one of talking donkeys. Unlike Dorothy and the Wizard of Oz, where Dorothy can't find a place where people aren't trying to kill her, the talking animals are all friendly. Button Bright does get cursed with a fox's head and the Shaggy Man with a donkey's head but the animals thought they were doing them a favor!
After a brief encounter with the Musicker, who is an annoying living accordion, Dorothy and her friends the Scoodlers, the one dangerous thing in the entire book. They can take their heads off to throw them at people and they intend to eat the party. The Shaggy Man ultimately thwarts them by catching their heads baseball style and throwing them down a gulley.
At last, Dorothy and her friends reach the deadly desert that surrounds Oz, whose sand will kill you with a touch. So the Shaggy Man summons up his friend, Johnny Doit, who has to be the godfather of steam punk, who builds them a sand boat to cross the desert and get to Oz.
Once there, a magical pool restores the heads of Button Bright and the Shaggy Man. Then, they go to Ozma's fabulous birthday party, which includes guests from several of Baum's other books. At the end, everyone gets to go safely home, except for the Shaggy Man who stays in Oz.
The Shaggy Man is an interesting character to me in many ways. In addition to the whole stranger danger bit in the first chapter, he's a homeless American with a magical artifact, the love magnet, who can summon up a powerful buddy in the form of Johnny Doit. For a guy whose schtick is ragged clothing, he's pretty powerful.
The Shaggy Man was apparently one of Baum's favorite characters and he does show up a lot in later books. He's never quite as powerful but he never loses his optimistic outlook.
Both Button Bright and Polychrome also show up in a lot of later books. In fact, they are at their most helpless in the Road to Oz. They are both allowed to grow up a bit and have character development. In fact, I'd say the Road to Oz doesn't even hint to how cool they get to become.
The next time they show up, it's in a non-Oz book, Sky Island. Which is one of my favorite Baum books. In it, Button Bright is a much more capable adventurer and Polychrome is practically a walking deux ex machina. Fun times.
In addition, there are appearances from a bunch of Baum's non-Oz books at Ozma's birthday party. Characters from Dot and Trot of Merryland, the Life and Times of Santa Claus, John Dough and the Cherub, and Queen Zixi of Ix all show up.
This is significant for me personally since I decided that I needed to actually read all those books, plus the rest of Baum's fantasy books.
The Road to Oz isn't the most dramatic or significant book but it does seem like Baum had fun writing it and I did have fun reading it.