The book is a collection of two short John Carter stories.
John Carter and the Giant of Mars
John Carter must battle Pew Mogel who was a protégé of Ras Thavas. He wants to conquer the world like every typical madman. He has an army of white apes that he transplanted the brains of men into. He also has created a fifty foot giant named Joog. John Carter rallies the forces of Helium and his friend Tars Tarkas to defeat the huge but slow witted Joog.
Skeleton Men of Jupiter
John Carter and Dejah Thoris are kidnapped by the Morgors. The Morgors are a race of men that rule the planet Sasoom(Jupiter). The Morgors have very tight skin which make them look like skeletons. They hope to gain information for there planned conquest of Barsoom. Carter, Dejah and some other captives escape and make it to an island still free of the Morgors.
Well the final Martian book is somewhat of a mixed bag. The Giant of Mars is actually written by Burrough’s son Jack Burroughs. It is quite obvious that Burroughs didn’t write this story. The story is also not very good.
The Skeleton Men of Jupiter on the other hand is an excellent story. Burroughs creates a whole new exciting world in Jupiter. Unfortunately he died before subsequent stories could be written and the plot is left hanging.
My final thoughts on the Martian series. I think they were the best of the worlds that Burroughs created. It really took me to an exciting world when I was a teenager. I don’t think there was a single book in the series that I didn’t enjoy.