By Frank Herbert
I don't recall how long it's been since I last read Frank Herbert's dune books and that suggests that it's been a while. Since the last read-through I'd formed the notion that God Emperor of Dune was the best of the bunch. Now that I've read it again I'd like to revise that notion and suggest the Children of Dune is the best of them.
God Emperor of Dune finds Leto, son of Paul Atreides, about 3,000 years into his reign as the God Emperor, a creature who is a combination of man and sandworm. Which is an interesting enough concept but what it means in this volume is that the all-knowing, all-seeing Leto is basically rather bored with existence. The downside for the reader is that he tends to pontificate at rather great length, perhaps in an attempt to transmit that boredom to us. It worked.
Actually, that comes off as a little more harsh of a critique than circumstances warrant. There are some fairly interesting plot threads that find the usual Dune factions scheming and conniving and hoping that they'll be able to knock of the old worm. Which is no small feat and I won't say how it turns out except to say that things pick up quite a bit at the end and Herbert winds things up in a fairly interesting manner.
It's worth a look but only after you've read Dune and Children of Dune. And Dune Messiah, if you're keen to, though you wouldn't be missing much if you skipped that one.