With all the main events of Frank Herbert's Dune universe now in the bag, all that remains is for his team of successors (Paul of Dune, 2008, etc.) to fill out the corners.
Chronologically, this one picks up immediately following Dune Messiah. The Mentat Emperor and omniscient Kwisatz Haderach Paul Atreides, blinded by an atomic weapon and no longer commanding his oracular vision, has walked off into the sands and is presumed dead. Paul's Bene Gesserit mother Jessica and warrior-troubadour Gurney Halleck return from Caladan to assist 16-year-old regent Alia. Duncan Idaho, the swordmaster ghola, clearly has regained all his former memories and will wed Alia in due course. Alia releases the Corrino princess Irulan, Paul's wife, from a dungeon and orders her to help counteract the propaganda spread by elusive gadfly Bronso of Ix. What Jessica knows, and Alia doesn't, is that Bronso was once Paul's boyhood friend (their story is told in flashback) and that Paul charged Bronso with the very task that Alia now condemns him for. The Dune juggernaut rolls on; pity it didn't occur to Brian and Kevin that the reason Frank didn't write Dune Messiah through Children of Dune as a continuous saga was that little of significance or interest occurs in the interim.
Slim pickings, even for Dune fanatics.