Heretics of Dune is set 1,500 years after the events of God-Emperor of Dune. The death of the God-Emperor led to a famine times in the Old Imperium. Spice and other commodities became scarce in the aftermath and humanity, free from the grip of Leto's control, spread out into the Scattering. In the present time, the Bene Gesserit are the main organizing force in the Old Imperium, forced out of the shadows and into governing directly. The Tleilaxu are the other major power in the Imperium, now with the capability of making artificial Spice and with enhanced Face Dancers capable of capturing their victim's persona as well as stealing their likeness. The Spacing Guild has mainly been side-lined with the advent of Ixian navigation machines.
Creeping back into the old Imperium from the outskirts of the Scattering are the Honored Matres, a hyper-sexual sisterhood that dominates through sex and violence. They greatly outnumber the Bene Gesserit and begin to storm the old Imperium. Mainwhile on Rakis (formerly Arrakis aka Dune) a girl has been discovered that can control the sandworms. The Bene Gesserit have engaged in an ambitious project to utilize the girl, Sheeana, to their own ends. To aid their efforts to control Sheeana, the sisterhood has commissioned a new Duncan Idaho ghola from the Tleilaxu, though the Tleilaxu are playing their own game. Training Duncan for his role are Reverend Mother Lucilla and retired Supreme Bashar Miles Teg, the former commander of the Bene Gesserit military. Reverend Mother Superior Taraza meanwhile coordinates the events, with Reverend Mother Darwi Odrade as her representative on Rakis.
Which of the major powers will survive? Will the new Honored Matre sisterhood come to dominate the old Imperium? How does Sheeana control the worms and what role does she play in humanity's future?
Dune contains examples of:
- Authority Equals Asskicking: Miles Teg and how! Supreme Bashar of Badass.
- Badass Army: Tegs Bene Gesserit military
- Badass Bookworm: Teg again, the Mentat-Bashar
- Big Bad: The Honored Matres
- Big Eater: Miles Teg in Heretics of Dune undergoes a transformation that unlocks his Super Speed powers, and as a consequence, has to consume many, many normal human portions to satisfy his hunger. Justified as his metabolism is accelerated to compensate for the increased energy demands. This is commented upon with amazement by the people who observe him eat.
- Bizarre Sexual Dimorphism: There are no female Tleilaxu. This is because the axlotl tanks are their females, having been engineered into being just gigantic wombs on life support.
- By the Eyes of the Blind: Inverted. Siona and her descendants cannot be detected by prescience.
- Came Back Strong: Miles Teg after the T-Probe
- Cat Girl: The Futars are the creation of Lost Tleilaxu returning from the Scattering. They're basically humanoid cat-people, and are kept as pets and feral weapons by the Honored Matres, despite being designed originally as weapons against them.
- The Chessmaster: Taraza/Odrade (Dar & Tar) and Teg.
- The Chosen One/Messianic Archetype: Sheeana in the final two books, though she doesn't get to fulfill that role, being instead set up for it as a decoy to get the Honored Matres to destroy Arrakis. Her ability to command sandworms is still useful, though and there was some hint there may still be a role for her in that direction.
- Combat Clairvoyance: After his transformation under the T-probe, Miles Teg has this ability cranked Up to Eleven, to the point where he can see the positions of the normally undetectable no-ships.
- Crazy-Prepared: Miles Teg is so prepared, he puts a lot of the Reverend Mothers he deals with to shame.
- Dragon with an Agenda: Logno manages to slip poison into Dama's drink in order to assume the role of Great Honored Matre. Not that it does her much good.
- Emotions vs. Stoicism: The Bene Gesserit stress emotional control at all times as both proof of humanity and a basic survival tool with the Litany Against Fear. Unlike Vulcans, they're more than happy to use emotion as a tool to manipulate others — their emphasis is control, not denial. And it later turns out to be a weakness that Odrade (and Murbella) must reverse.
- Eye Scream: "Tormsa's eyes exploded in blood."
- Faster-Than-Light Travel: Foldspace
- Follow the Leader: The Bene Tleilax finally manage to create synthetic Spice in their tanks by Heretics of Dune.
- Identical Grandson: The Atreides "look", which is so distinctive that Miles Teg looks like his ancestor Duke Leto I, 5,000 years later. Teg was bred by the Bene Gesserit to look like Leto I in order to help a certain someone regain their memories. Keep in mind that the Bene Gesserit plan actions far, far, far in advance.
- Invisibility Cloak: No-Chambers and No-Ships. Not your average cloaking device; even prescient scryers cannot find you. Except Miles Teg.
- Manchurian Agent: Duncan Idaho once again has a little surprise built-in by the Tleilaxu in hopes of countering the Bene Gesserits plans. However, he ends up snaring Murbella of the Honored Matres instead.
- Meaningful Name: "Patrin" or "pattaran" means a path-marker in Romani. Patrin showed Teg the way to the Harkonnen no-globe.
- New Powers as the Plot Demands: Miles Teg's exposure to a T-Probe gives him Super Speed just in time to save his life, though the T-Probe was meant to kill him.
- No Woman's Land: Tleilax
- The Plan: Tarazas plan to lure the Honored Matres into destroying Rakis.
- The Bene Tleilax again, Up to Eleven, since they've spent millennia constructing the image of evil stupidity to hide the fact that they're secret Zensufis (not to be mistaken for Zensunnis, from whom the Fremen descend — Heretics is most explicit about this).
- Super Speed: In Heretics of Dune, Miles Teg gets this power as a result of a botched interrogation — implied to be a result of the unique mechanics of the interrogation device unlocking a latent genetic talent. His speed also includes accelerated reflexes, slowed time perception, a form of Super Senses (explained as an amplification of his Mentat training), and massive boosts to his metabolic rate and the oxygen storage capacity of his blood to handle the increased energy demands. The effect also turns him into a Big Eater, which is played for both drama and laughs. Fortunately, he can turn the ability on or off at will.
- Take That! with this passage:As far back as the Old Empire there had been a pejorative label for the small rich and Families Minor arising from the knowledge of a rare wood's value. 'He's a three P-O,' they said, meaning that such a person surrounded himself with cheap copies made from declasse substances.
- Time Skip: 1,500 years since God-Emperor of Dune
- To Win Without Fighting: In the Back Story Miles Teg was a famous Bene Gesserit military commander.Teg's reputation was an almost universal thing throughout human society of this age. At the Battle of Markon, it had been enough for the enemy to know that Teg was there opposite them in person. They sued for terms.
- You Can See Me?: The Honored Matres get a nasty surprise when Miles Teg pinpoints and eliminates all their supposedly undetectable no-ships in the final battle.