JOHN CARTER OF MARS

Four Square paperback, June 1968. Cover artist is Josh Kirby
(thanks, Mark).

"Here is the eleventh, and final, book in Edgar Rice Burroughs' best-selling Martian Series. John Carter is pitted against the infamous Pew Mogel, who has kidnapped his beloved wife, Dejah Thoris. The famous Warlord of Barsoom is lured to a deserted city on the shores of the dread sea of Korvas. But instead of his wife, he finds a huge synthetic giant and hordes of great, white apes into each of which the brain of a man has been grafted. It takes all the skill of Carter's famous fighting arm and extraordinary agility to preserve his life - and meanwhile the sands of time are running out for Dejah Thoris!"