With the intended close of the Oz series in 1910, L. Frank Baum really wanted to try his hand at other stories. I've already written that I see this period as a time when Baum was trying to reinvent himself as an author.
The first book-length fantasy he released was The Sea Fairies. Baum tries to change his style by not jumping into the adventure right away (whenever an earlier Oz book had required someone to come to Oz or a bordering country from the Great Outside World, the transportation usually happened in the first chapter, or, in the case of The Emerald City of Oz, when it happened in the same chapter Dorothy first appears in), he took his time to introduce the characters. However, he did not bore the reader by following a few days in the life of Trot and Cap'n Bill, the protagonists, and instead gets the adventure started in the second chapter.
The book began with Trot and Cap'n Bill talking by the ocean about mermaids. Cap'n Bill swears that no one has seen a mermaid who has lived to tell the tale, as they will pull careless admirers overboard, where they will drown. The curious Trot is not sure that mermaids are so cruel, and wonders that if no one who ever lived has seen a mermaid, how do we know what they're like? She suggests to Cap'n Bill that maybe someone found a photograph, though that does raise the question of how someone could photograph a mermaid without seeing them.
The next day, Trot and Cap'n Bill go boating, and decide to visit Giant's Cave, a cave in the sea. Inside, they are greeted by mermaids who make them an offer: to prove Cap'n Bill is wrong about the mermaids, they will let the two visit them undersea.
Trot eagerly takes them up on the offer, diving into the water and emerging with a mermaid's tail. Cap'n Bill is a little more reluctant, but eventually follows.
As they make their way to the home of the mermaids, Trot and Cap'n Bill ask many questions of the mermaids they are accompanying, who are named Clia and Merla. Among these, Baum sets up some rules of how life underwater would work. Instead of having gills, there is a tiny space of air around the mermaids and their visitors that allows them to breathe, the oxygen being replenished from the water. The visitors later deduce that the same air space keeps the pressure from being so far underwater from harming them.
They reach the palace where they meet Queen Aquareine, who introduces them to a soon-arriving visitor, King Anko. Anko is a sea serpent, and one of the three rulers of the three oceans. We are left to assume he is the King of the Pacific Ocean. Given that the book is connected to the Oz mythos, it is safe for us to assume that the sea serpents answer to Bo, the Master Mariner of the World, introduced in The Life & Adventures of Santa Claus.
The Queen puts Trot's mother (still on land) in an enchanted sleep, where she will awaken when Trot returns. While Trot's mother reappears in Sky Island, she is oddly absent from The Scarecrow of Oz and never reappears.
Trot and Cap'n Bill are treated royally while they are guests in Aquareine's palace. Later, they get to meet the amusing sea life, including aristocratic codfish, mackerels who claim that those who get caught go "to glory!," an octopus who is sad because of his reputation, and a sea horse.
The sea horse I found to be a little interesting, as a sea horse was part of the signature of W.W. Denslow, Baum's former illustrator. Denslow was even nicknamed "Hippocampus Den," "hippocampus" being the name of the sea horse genus. While speaking to the octopus, he says that the sea horse "used to be a merry and cheerful fellow, but "since they named him 'hippocampus' he hasn't smiled once." Was Baum possibly taking a stab at his former friend? It'd be interesting to explain why, but something tells me he wasn't.
The visitors, Aquareine, and Clia set out to visit an island near the Arctic Circle, and then to visit King Anko. Magic Circles are drawn around Trot and Cap'n Bill to keep them from harm, especially from the devil fish, who are the servants of Zog, who, in traditional Baum fashion, has not been introduced until now. Zog is part man, part beast, part fish, part reptile, and part bird, and he lives in a castle that has been hidden away.
On their way to Anko's palace, the four are trapped by the devil fish and are forced to enter Zog's domain. Zog promises that he will find a way to kill them, but he will not do so immediately, as he gets joy from torturing and killing, not dead things. Since he cannot kill King Anko, who imprisoned him in the palace, he will annoy Anko by killing his friends.
The prisoners are given comfortable rooms, and are fed well, but Cap'n Bill reflects that pagan peope (like the Aztecs) would treat their human sacrifices royally before killing them. However, they discover Zog's slaves are people he decided to save from drowning in shipwrecks. By giving them gills (it's not explained how they defy the pressure of the water), Zog equipped them for living under the sea. Among them is a prince named Sacho and Cap'n Bill's brother Joe, who is practically his twin, down to the wooden leg.
I wonder if Baum had legends of the lost island of Atlantis in mind in this story, with some telling of fish-men who live underwater.
Zog tries to torture his prisoners with a gigantic crab-like monster called the Yell-Maker, by freezing the water in their rooms, and making the water boiling hot. However, each time Queen Aquareine comes to the rescue.
The Queen asks a goldsmith to make a sword for her to use so they can escape, and in return, Cap'n Bill parts with many items in his pockets. The four leave the palace, and fight through the top of the Great Dome, but Zog himself comes after them, showing his body, similar to a sea-serpent. He destroys Aquareine's golden sword and makes her lose her fairy wand, but before he can do any more, King Anko arrives and squeezes Zog into a shapeless gelatinous mess, continuing Baum's last-minute rescues. However, Baum managed to write the escape, pursuit and victory so well that it becomes a real page-turner.
Anko takes the four to his home, where he shows them the entire length of his body (so long they can't see the end of it) and commands them that Trot and Cap'n Bill must be returned home.
On their way back, the four check in on Zog's servants, who have decided to make Cap'n Joe their king. Then, back to Giant's Cave, where Trot is given a ring that she can use to summon the mermaids. When they return to the boat, Trot and Cap'n Bill resume their human form, and are happy to realize that they have seen mermaids and have lived to tell the tale.
Although The Sea Fairies was not a financial success for Baum, I must admit that it is not one of his worst books. He did seem to lose it, with more than one chapter dedicated to tours of the ocean that don't add to the plot, and the villain, who didn't have much of a reason to attack the protagonists, being defeated a bit too suddenly.
I could easily see the book being adapted for a film. I read that an independent producer had taken it up as a possible project when Disney was preparing to release Return to Oz, but it seems the project was shelved. Trot and Cap'n Bill were replaced with the Oz Kids (minus a few of them) and the story was re-located to a lake in Oz for the Oz Kids animated video Journey Beneath The Sea.