There are some of us who feel that Frank Herbert should never have written a sequel to "Dune," much less three of them. "Dune," given Mr. Herbert's talents and limitations, was just about a perfect science fiction, as well as a lecture on ecology. The desert planet, the giant sand worms, the blue-eyed Fremen, the water suits, the narcotic spice, the God-making, the witches, the telepathy and the prescience—how could they have been improved upon? And they haven't been, not in "Dune Messiah," in "Children of Dune" or in "God Emperor of Dune."

Some of us, however, are outnumbered by hundreds of thousands of readers who insist on a "Dune" redux every five years or so…. Mr. Herbert is the prisoner of a cult, his own Leto. I suspect he would prefer to branch out and risk something else, as he did in "The Green Brain," "Whipping...