The Tleilaxu, led by Hidar Fen Ajidica, took advantage of the suboids desire to not violate the prime commandment of the Orange Catholic Bible against producing Thinking Machines.
For months prior to the Tleilaxu invasion of Ix, designed by Elrood Corrino IX who wanted revenge against Dominic Vernius, the Tleilax secretly stirred up rebellion amongst the suboids.
Eventually, suboids backed up by the Tleilaxu, managed to blow two of the diamond columns, and part of the overhead crust of Vernii collapsed, resulting to serious damage of the city. Leto Atreides I and Rhombur Vernius were escorted by Commander Zhaz who guided them in a secret corridor and a railcar that would lead them to the crust caverns. Another explosion occured which destroyed a walkbridge, sending pedestrians to their doom; comcommand learned that the Tleilaxu were involved, and their engineers had blown the recycling lines and the pipelines that feed heat from the molten core of the planet. During the tumult an explosion occurred in the Guild Embassy Building and S'tina Pilru was killed.
Courier Yuta Brey was transported immediately to Kaitain and notify the Emperor about the problem. She and ambassador Cammar Pilru had an audience with the emperor opposing Mofra Tooy of the Tleilaxu, who claimed that the Ixians violated the Butlerian Jihad. Elrood gave the Tleilaxu two days to "compile the evidence" before stopping the hostilities, backing the Jihad Appendix of the Great Convention. Enraged for the emperor's indifference, Cammar planned to call a Security Council within the Landsraad.
Meanwhile the Ixians did not manage to stand their ground and were herded in smaller and smaller areas. Through well-planned sabotage and carefully arranged bottlenecks, the Tleilaxu managed to control most of the underworld. The suboids who were manipulated by the invaders, vastly outnumbered the Ixians.
When Rhombur and Leto were transferred to a secret security chamber, they were soon visited by Dominic Vernius and Kailea supporting Shando who was injured by a maula pistol trying to protect Kailea. The couple told to the children that their House would go renegade, and Duke Paulus Atreides sent a rescue mission for the three heirs.
This peaked with the full-scale invasion of Ix by the Tleilax, who were helped by the Emperor's Sardaukar troops.