The Lost Tleilaxu are a fictional organization from the Dune universe created by Frank Herbert. Descendants of the Tleilaxu, they are first mentioned in Herbert's Heretics of Dune (1984); however, the group is not referred to explicitly as "Lost Tleilaxu" until the 2006 Brian Herbert/Kevin J. Anderson sequel to the original series, Hunters of Dune.
As described to Heretics of Dune, when the 3,500 year reign of God Emperor Leto II comes to an end with his death at the end of God Emperor of Dune (1981), humanity is thrown into chaos. The breakdown of Leto's empire, severe famine on many worlds and the introduction of Ixian navigation machines causes billions of people to leave the settled worlds, striking off into unknown space in a diaspora known as The Scattering. The people who had gone out into The Scattering are often referred to as the "Lost Ones."
In Heretics of Dune, the descendants and "creations" of these Lost Ones have begun to return to the Old Empire, including the fierce Honored Matres and a new breed of Tleilaxu. Tleilaxu Master Waff notes:
Descendants of Tleilaxu from the Scattering had told him all they could about [the Honored Matres] ... He did not fully trust the returned Tleilaxu descendants, either. Their accents were strange, their manners even stranger and their observances of the rituals questionable. How could they be readmitted to the Great Kehl? What possible rite of ghufran could cleanse them after all these centuries? It was beyond belief that they had kept the Tleilaxu secret down the generations ... They were no longer malik-brothers and yet they were the only source of information the Tleilaxu possessed about these returning Lost Ones. And the revelations they had brought! Revelations that had been incorporated in the Duncan Idaho gholas — that was worth all of the risks of contamination by powindah evil.
In Chapterhouse: Dune, the last Tleilaxu Master Scytale tells the Bene Gesserit leader Darwi Odrade that "Descendants of people we sent into the Scattering returned with captive Futars. A mingling of human and cat, as you doubtless know. But they did not reproduce in our tanks. And before we could determine why, the ones brought to us died." Both Odrade and Scytale realize this was a ploy of the descendant Tleilaxu to gain the confidence of the Masters and yet not divulge their secrets.
In this sequel to the original series, the descendant Tleilaxu, now called the "Lost Tleilaxu," are at odds with their forebears. Ruled by a council of Elders, the Lost Tleilaxu have at their disposal a subgroup of advanced Face Dancers who cannot be detected by even the Bene Gesserit. The highest-level Face Dancer is Khrone, who is trusted to execute the most important tasks of the Elders. To further their goals for domination of the universe, the Lost Tleilaxu ally with the Honored Matres to obliterate nearly all Tleilaxu planets. Despite having the technology to create gholas, the Lost Tleilaxu do not know how to manufacture melange in axlotl tanks (as the "original" Tleilaxu do) because that process was developed after their line of Tleilaxu departed the Old Empire. Their immediate goal is to rediscover this secret to break the Bene Gesserit monopoly on the all-important spice.
Ultimately Tleilax is invaded by the Honored Matres, killing all of the "original" Tleilaxu, except for Scytale, now prisoner of the Bene Gesserit. This leaves the "Lost Tleilaxu" as effectively their replacement in galactic politics, utilizing their advanced genetic technologies to further several clandestine goals.
It is revealed that the Lost Tleilaxu leadership has been infiltrated and overtaken by the Face Dancers; believing it is no longer necessary to pretend to be inferior to the Elders, Face Dancer leader Khrone kills the last true Elder, Burah. The Face Dancers have also secretly gained control of many similar power bases across the Old Empire. Under the leadership of Khrone, the Lost Tleilaxu's new primary goal is to find the Ithaca, the no-ship that escaped Chapterhouse. A minion of Daniel and Marty, Khrone believes their "infallible" projections that the Ithaca contains something or someone important to them, the necessary fulcrum to influence Kralizec, the "battle at the end of the universe."[1]
Second-rank Lost Tleilaxu Uxtal had served Elder Burah, transcribing meetings and disseminating the information to other Elders. After Burah's murder, Khrone sends Uxtal to the Tleilaxu capital, Bandalong — now ruled by renegade Honored Matre leader Hellica — to pacify Hellica by having Uxtal produce (under threat of death and using axlotl technology) the orange adrenaline-enhancing drug used by the Honored Matres.
Khrone implements a parallel plan to the pursuit of the Ithaca, purportedly to create other weapons for Daniel and Marty's conquest of the universe. He tasks Uxtal to create a ghola of Baron Vladimir Harkonnen from genetic material found in a damaged nullentropy tube (from the charred corpse of a Tleilaxu Master) in Bandalong. This ghola is to be used to condition the subsequently-grown ghola of Paul Atreides, called Paolo, himself created from blood found on an artifact from Caladan. Though Daniel and Marty lose interest in the project, Khrone continues; the Face Dancer has his own agenda for domination of the universe, and believes that, like the Tleilaxu, Daniel and Marty can be fooled.
The Guild Navigator Edrik comes to Tleilax seeking Uxtal's knowledge of axlotl tanks; the Navigator fears his kind's obsolescence when the new Ixian navigation technology (secretly masterminded by Khrone) becomes available. He seeks an alternate source of spice to break the Bene Gesserit monopoly, but even Uxtal believes that secret has died with the Tleilaxu Masters murdered by the Honored Matres. Eventually he is able to access the genetic material of deceased Master Waff, and through an accelerated process creates several (ultimately flawed) Waff gholas, hoping to unlock the secret of producing melange in the tanks. The entire universe is unaware that in the events of Chapterhouse Dune, Scytale had been forced to give the passengers of the Ithaca the secret, and it was in use on the no-ship as their primary source of spice.
Murbella, leader of the Bene Gesserit New Sisterhood, conquers Tleilax, discovering that Matre Superior Hellica and several of her elite guard are also Face Dancer duplicates. Uxtal is devoured by hungry sligs, and the sole remaining Waff ghola escapes. He finds refuge with the Spacing Guild, offering Edrik something better than artificial melange — the genetic knowledge for the Guild to create their own, optimized sandworms, the natural origin of the spice cycle.
Finally, it is revealed that the force behind the plot against humanity is in fact mankind's ancient enemy, the thinking machines; Daniel and Marty are in fact new incarnations of machine leader Omnius and his second-in-command Erasmus, introduced in the Legends of Dune prequel trilogy by Brian Herbert and Kevin. J Anderson.