Children of Dune, the third book of Frank Herbert's series, while not one of the best of the series is certainly an interesting continuation of the Dune chronicle. In this book, the twin children of Paul Maud'Dib Atreides, hero of the first two books of the series must contend with the continued upheaval in the galaxy caused by their father's violent ascent to the imperial throne.
The background for this book is complex: The fallout from Paul's takeover is massive. Paul's ascent to the throne, while possibly the least evil course for humanity given the corruption and stagnation in the human race until his takeover, unleashed a bloody jihad on the galaxy. Paul's original followers, the desert-bred and half wild Fremen have become the leaders of the jihad. As army officers, they are still great warriors; however, they have lost much of their mysticism and their wildness. As a result, some of the Fremen have turned against Paul, as originally explored in the previous book, Dune Messiah. On top of this, Paul's death in the previous book has left only his two young children to rule. Given their youth, the galaxy is being run in their name by their increasingly corrupt and insane aunt, the Abomination Alia, possibly in league with their grandmother who may also be a traitor to them and their step-mother Irulan.
As a result of all this, the book focuses on the children's attempts to take control of the empire and save it from those who will destroy the entire galaxy. Furthermore, they must find a way to take control of the empire while avoiding the mistakes of their father, Paul, who unleashed the violent jihad on the galaxy, allowed himself to be set up as a Messiah and became so addicted to the Spice melange which allowed him to see the future that he became unable to act except as dictated by his visions.
The children strike on a horrifying method to take over the galaxy but avoid the temptation of doing so by foreseeing the future exactly. I will not reveal their method because one of the best parts of the book is the way their method unfolds, twisting and turning until the final horror is revealed. The book is worth reading just to have that revelation.
Another interesting aspect of this book is the fact that for the only time in the Dune series, Herbert's main characters are young children. Although they have collected wisdom greater than anyone else in the galaxy, except possibly their aunt Alia due to their parentage, Herbert is still able to deal with them as children. Herbert shows his deftness as an author, not simply as a sci-fi writer.
The only flaw with this book is that it is significantly less mystical than the prior books. Although the result of the path chosen by the children is very mystical, as revealed in the next book, this book primarily deals with plot rather than Herbert's amazing insights into humanity and religion.