Ghost of a flea

In recent years, Herbert’s son, Brian, and Kevin J. Anderson have collaborated on their own series of “Dune” novels, in which the authors fill in the back stories of the franchise’s central characters without hitching their sandworms to Frank Herbert’s unfinished opus. (The dust jacket to one such prequel, “Dune: House Corrino,” announces it is “The Triumphant Conclusion to the Blockbuster Trilogy That Made Science Fiction History!”) But the legend of “Dune” still wasn’t finished: while researching their books, Anderson and Herbert the younger say, they discovered a set of safe-deposit boxes containing printed notes and “two old-style computer disks,” on which their predecessor had left detailed plans for a seventh “Dune” novel that would begin where “Chapterhouse” left off. After determining that this newly unearthed material would, in fact, require two books to relate in its entirety (and perhaps filing the anecdote away for use in a future novel, “The Frank Herbert Code” ), the authors set to work on “Hunters of Dune” and the forthcoming “Sandworms of Dune.” Oh, and also a companion volume, “The Road to Dune.”