The ninth book in the series.

Publication year: 1940
Format: ebook from Gutenberg
Page count: 192
The incomparable Dejah Thoris has been in a flier accident and was injured terribly. Helium’s best doctors can keep her alive but not cure her; only one man can do that: Ras Thavas, the Master Mind of Mars. But he has disappeared and John Carter leaves Helium to search for him. His friends and family (clearly remembering previous times…) plead him not to go alone and he takes with him one man from his guard: young warrior called Vor Daj. Together, they fly towards Ptarth where Ras Thavas’ erstwhile apprentice lives because they hope that he has some clues to the great surgeons’ whereabouts. However, (and extremely fortunately for our heroes) their miraculous compass is just a bit off and the flier takes them near the Toonolian Marshes which is rumored to be full of savages. Strange creatures take John and Vor Daj captive and transport them on the backs of huge birds to the city of Morbus.
The strange creatures are hormads and live in Morbus. They are vat grown red men (and indeed all seem to be male) who are grotesque and hideous in appearance. They’re also slow-witted. The most intelligent of them have formed the Council of Jeds and have imprisoned Ras Thavas and forced him to work for them. The hormad jeds intend to conquer whole Mars with their rapidly grown synthetic men. They aren’t good with the sword but because they can’t be killed, the jeds intend to just grow so many of them that they will take down everyone else with sheer numbers.
This time the narrator is Vor Daj. Early on, he sees a beautiful girl and falls in love with her. The girl, Janai, is also imprisoned in Morbus and Vor Daj wants to free her. In order to do that, he realizes that he has to put his brain into a body of a hormad so that he can be near her and protect her until he and John figure out a way to escape. So, he asks Ras Thavas to do that and the great surgeon agrees. So, Vor Daj’s body is hidden while he starts his adventures in a horribly deformed body. Of course, things go wrong and soon Vor Daj is in danger of losing his real body. He also keeps his real identity a secret from Janai, fearing that she will forever see him as a hormad.
The hormads are an interesting invention. Their bodies and faces are usually twisted; one might not have legs and another might have an ear growing in the middle of his face. Yet, they’re unkillable; parts just go on moving and a new body can be grown to a head. They can only be destroyed with fire.
Vor Daj meets another new culture which is a described as a group of primitive savages. They are not tharks nor red men but marsupial Martians who hop around with their tails and hind legs. In contrast to the other Barsoomians, they don’t show bravery in war but instead only attack when they have overwhelming numbers on their side.
The hormads are imaginative and quite horrible in their desires. The most intelligent ones want red men bodies and force Ras Thavas put their brains into the bodies of captured red men. So, it’s not possible to know who is who. The book even has a little philosophy about it.
Unfortunately, there are some sloppy errors in the book. The worst of them is perhaps the mix up with two characters but the ending is also less satisfactory than the other Barsoom books because we don’t know the fates of the major antagonists. They can be assumed but we don’t see them.
Also, even though the Martians spring fully grown from eggs, which we are told in this very book, there is a slave boy in this book.
Still, this is a very imaginative book and worth reading if you’ve enjoyed the previous books.