Ace Double Novel: King of the Fourth Planet by Robert Moore Williams

King of the Fourth Planet (1962), a novel by Robert Moore Williams

At left: Paperback (New York: Ace Books, 1962), 126 p., #F-149, 40¢. Cover art by Ed Emshwiller. An Ace double novel, bound with Charles V. De Vet and Katherine MacLean’s Cosmic Checkmate.

Here’s the blurb from inside the front cover:

“John Rolf fled his own guilt when he abandoned the corruption of Earth for a life of meditation on the many levels of Mars’ mountain, ruled as tradition had it by a king with amazing powers. In this serene climate, Rolf perfected an invention that would explore the human mind -- and thereby unearthed a menace that threatened to annihilate the ancient Martian culture. The discovery confronted Rolf with the crisis of his loyalty and his past. To defy Earth, to save Mars? Yet only the King of the Fourth Planet would have the power to do so -- and everyone believed the king to be a myth.”

Williams' work was reviewed by critic Rich Horton. According to Google Book Search, SF author Lin Carter once called King of the Fourth Planet “a very forgettable novel.” Surprisingly, the book was included in a 2002 science fiction exhibit sponsored by the San Diego State University Library.

Robert Moore Williams is also the author of the collection When Two Worlds Meet: Stories of Men on Mars (1970).