John Carter of Mars

The final book in Edgar Rice Burroughs's career-spanning Barsoom saga is a slender volume containing two unrelated novellas. John Carter and the Giant of Mars: A mysterious figure named Pew Mogel kidnaps Dejah Thoris and offers to release her in exchange for control over Helium's iron works. The Skeleton Men of Jupiter: The ruling race of Jupiter, the skeletal Morgors, plot an invasion of the Red Planet with Helium as their first target.