It is eighty-three years after the last of the thinking machines were destroyed in the Battle of Corrin, after Faykan Butler took the name of Corrino and established himself as the first Emperor of a new Imperium. Great changes are brewing that will shape and twist all of humankind. The war hero Vorian Atreides has turned his back on politics and Salusa Secundus. The descendants of Abulurd Harkonnen Griffen and Valya have sworn vengeance against Vor, blaming him for the downfall of their fortunes. Raquella Berto-Anirul has formed the Bene Gesserit School on the jungle planet Rossak as the first Reverend Mother. The descendants of Aurelius Venport and Norma Cenva have built Venport Holdings, using mutated, spice-saturated Navigators who fly precursors of Heighliners. Gilbertus Albans, the ward of the hated Erasmus, is teaching humans to become Mentats…and hiding an unbelievable secret. The Butlerian movement, rabidly opposed to all forms of “dangerous technology,” is led by Manford Torondo and his devoted Swordmaster, Anari Idaho. And it is this group, so many decades after the defeat of the thinking machines, which begins to sweep across the known universe in mobs, millions strong, destroying everything in its path. Every one of these characters, and all of these groups, will become enmeshed in the contest between Reason and Faith. All of them will be forced to choose sides in the inevitable crusade that could destroy humankind forever….

In Brian Herbert and Kevin J. Anderson's Mentats of Dune, the thinking machines have been defeated but the struggle for humanity's future continues. Gilbertus Albans has founded the Mentat School, a place where humans can learn the efficient techniques of thinking machines. But Gilbertus walks an uneasy line between his own convictions and compromises in order to survive the Butlerian fanatics, led by the madman Manford Torondo and his Swordmaster Anari Idaho. Mother Superior Raquella attempts to rebuild her Sisterhood School on Wallach IX, with her most talented and ambitious student, Valya Harkonnen, who also has another goal—to exact revenge on Vorian Atreides, the legendary hero of the Jihad, whom she blames for her family's downfall. Meanwhile, Josef Venport conducts his own war against the Butlerians. VenHold Spacing Fleet controls nearly all commerce thanks to the superior mutated Navigators that Venport has created, and he places a ruthless embargo on any planet that accepts Manford Torondo's anti-technology pledge, hoping to starve them into submission. But fanatics rarely surrender easily . . . The Mentats, the Navigators, and the Sisterhood all strive to improve the human race, but each group knows that as Butlerian fanaticism grows stronger, the battle will be to choose the path of humanity's future—whether to embrace civilization, or to plunge into an endless dark age.