The Honoured Matres have nearly conquered the Bene Gesserit.  Arrakis, or Dune as we know it, is merely a smoking cinder, one of many on which the Maters left nothing or nobody alive.  It is Darwi Odrade's task to let the Bene Gesserit survive, even if that asks horrible sacrifices.  Even the planet they live on is sacrificed, as sand-trout is released to turn the green world they chose as their home into a new desert planet, mile after hot mile.

Many years now Duncan Idaho and his lover Murbella, the former Honoured Mater who is now being prepared for the Bene Gesserit's plans, live hidden in a non-ship, together with the last survivor of the Tleilaxu, the ever-grousing Scytale.  Miles Teg, a ghola made by the Bene Gesserit with technology taken from teh Bene Tleilax, needs training and education, and Idaho takes a large part of that upon him.  And while Darwi Odrade sends out some of her sisters into a new Scattering without knowing if they'll ever see them or their descendants again, she carefully prepares for the ultimate confrontation with the Honoured Matres...

Though this is the last Dune-book written by Frank Herbert, it feels as if this was not supposed to be the last, but unfortunatly Herbert died the year after Chapterhouse Dune was published.  The first three books could be the Paul Atreides trilogy, in the middle there's God Emperor of Dune, and the final three could have been planned as the Golden Path trilogy, with Chapterhouse Dune as the middle one of that trilogy.  That could explain about the only flaw this book has: its ending.  Just like in Heretics of Dune there are quite some story-threads, but this time the ending doesn't bring them together.  In stead plans are made for a battle, lots of fighting, then it's over, and then the Bene Gesserit turn out to be the victors - and that's it.  It leaves the reader a bit dazzled, as if there is more to come but there isn't.

Except for the ending Chapterhouse Dune is an excellent read, just like any other book in the Dune saga.  It has strong sympathetic characters, a bit overserious and often with hidden meanings everywhere, but very credible.  The few pages we spend in the company of the Honoured Matres gave just enough and concealed just enough to leave the reader hungry for more, and one felt for poor Duncan who felt his lover slip away like sand through his fingers as she is more and more embedded into the Bene Gesserit.  Overall I liked it a lot - even despite the sort of abrupt ending.