The machine evermind Omnius is continuing with its plans to eradicate all humans in the universe. After first being suggested by the traitor Yorek Thurr, an RNA
retrovirus is designed by the captured
Tlulaxa Rekur Van and the independent robot
Erasmus. Omnius then launches capsules containing the retrovirus to infect the planets inhabited by the hapless humans. With a 43% direct-mortality rate, the virus succeeds in effectively crippling the
League of Nobles, leaving them vulnerable to attack. It is discovered that consumption of the spice
melange has the effect of both bolstering immunity to the retrovirus and stopping its progression in some of those already infected. Omnius, unaware that the virus has been effectively stopped, prepares for the second phase of its attack. Gathering the bulk of the machine armies stationed at the different synchronized planets, the evermind launches the massive fleet towards the League capital
Salusa Secundus. After learning of the imminent destruction headed their way in the form of the machine fleet,
Vorian Atreides formulates a plan whereby the humans can launch pulse-atomic attacks on all of the undefended
Synchronized Worlds, ridding the universe of Omnius altogether. However, this plan called for the use of the still unreliable space-folding technology in order to carry out the attacks before the machines have a chance to recall the fleet en route to Salusa. The Great Purge is successful in destroying Omnius on all but one planet, albeit with an appalling cost in human lives because each planet was turned into slag, and while all the machines were obliterated, all the captured humans and slaves on these planets were also killed. Each time the human armies fold space to a new location there is a 10% attrition rate due to the undependable space-folders because of the uncertainty principle. In all, it amounted to billions of lives lost. The humans are also unable to destroy Omnius on the primary synchronized world,
Corrin. While the other Evermind incarnations are being attacked, the cogitor Vidad travels to Corrin and warns Corrin-Omnius of the human counter-offensive. The machine fleet is recalled to defend their last remaining stronghold. Despite this,
Serena Butler's Jihad is declared over. The Great Purge ended with an impasse between humans and thinking machines on the planet Corrin. While unable to destroy the machines, the human army is able to trap them on Corrin by surrounding the planet with a net of scrambler satellites, so that any thinking machine attempting to leave would have its gelcircuitry mind destroyed. This situation continues for almost 20 years with the machines unable to escape, and most humans unwilling to enter another battle. Omnius, again at the suggestion of Thurr, sends machines with primitive minds that can evade the scrambler network to attack Salusa Secundus and
Rossak. These attacks have a limited effect, but are enough to remind the humans that the machines are still a threat. Touting his victory over the
Titans (see
below), Vorian Atreides convinces the League to attack Corrin. Facing robots using human shields and unable to use their main tactical weapons due to treachery by Abulurd Harkonnen, the Army of Humanity is bogged down around Corrin. They are forced to use most of their atomics to destroy the robot defenders. There is a ground offensive by
Ginaz mercenaries that finally destroys Omnius, but not before he sends out an unknown radio message into space. Following the Battle of Corrin, Viceroy Faykan Butler renames himself Faykan Corrino in commemoration.
The Cult of Serena Having seen her parents succumb to the Machine ("demon") Scourge, and barely surviving herself,
Rayna Butler begins her personal crusade against the thinking machines. Claiming to have had a vision of Serena Butler herself (possibly a hallucination caused by her illness), Rayna begins smashing anything resembling thinking machines, including even innocuous devices, and desperately needed medical equipment. A new group known as the Martyrists who worship The Three Martyrs: Serena Butler,
Manion the Innocent, and
Iblis Ginjo, are instantly taken up by Rayna's mission. Led by Rayna, the
Cult of Serena causes even more mayhem for humans. Despite inherent hypocrisy (such as the destruction of some technology, but the continuous use of spaceships) within the group, the cult's legacy endures. The primary commandment in the
Orange Catholic Bible, "thou shall not make a machine in the likeness of a human mind" is attributed directly to Rayna Butler. Furthermore, the group is responsible for the strict laws banning all thinking machines under pain of death (and sometimes torture).
Destruction of the Titans During the 20-year impasse the three remaining Titans,
Agamemnon,
Juno and
Dante, are struggling to rebuild their
cymek empire. While surveying
Wallach IX, which has been devastated during the Great Purge, for possible survivors in need of aid, Primero
Quentin Butler (Faykan and Abulurd Harkonnen's father) is captured by cymeks, and taken to the Titan stronghold on Hessra. There he is tortured and converted into a cymek himself. After learning about this, Vorian Atreides feigns retirement and travels to Hessra. Once there he regains his father Agamemnon's trust. In a final coup, Vorian and Quentin successfully kill the Titans and their cymek underlings, but at the cost of Quentin's life. ==Legacy==