Cristane was an important Bene Gesserit sister and commando during the events of the Prelude to Dune series. She discovered the nature of the Amal Project, but was unable to transmit her report to the Sisterhood due to her capture by the Tleilaxu and her death at hands of Count Hasimir Fenring.
Sister Cristane was from planet Hagal, where she suffered abuse from her step-father. When the Sisterhood discovered her, they healed her psycological wounds with training, and made her one of the best commandos of the Bene Gesserit. Cristane received the delegation from Giedi Prime to Wallach IX, headed by Baron Vladimir Harkonnen, who was looking for retaliation against the disease he had acquired due to Gaius Helen Mohiam's revenge for being raped by him. Cristane and her sister used their mental tricks and skill to confuse the Baron, who runned away in fear from the Bene Gesserit homeworld.
Later, Cristane was the only sister (not Reverend Mother) who was present at the Council of Mother Superior Harishka, to deal with the pregnancy of the Lady Jessica and the requirement of Duke Leto Atreides to receive the no-ship that Count Glossu Rabban Harkonnen had crashed in the atmosphere of Wallach IX. Cristane recognized the noble duke' values, but affirmed that the no-ship was a dangerous weapon to handle it over to any member of the Landsraad, and that, moreover, Duke Leto was just a pawn in the Breeding Program of the Sisterhood.
When Count Hasimir Fenring introduced with the help of the Face Dancer Zoal a portion of synthetic spice (Amal) on a Guild Heighliner, it caused that the Navigator was poisened as soon as he received the synthetic spice gas and lost control of the ship, while the ship crashed the defensive atmosphere of the Bene Gesserit homeworld of Wallach IX. Cristane was sent by Mother Superior Harishka to inspect the disaster, that took place in a remote zone of the planet, while the Mother Superior redacted an urgent message to the Spacing Guild headquarters at Junction. The Guild informed Emperor Shaddam IV that two accidents had occured and that the contamined spice came from planet Beakkal, a selvatic homeworld. When Cristane asked with the powers of The Voice to a Guild worker what had happened, the man had no clear answers, but affimed that the ship was a Dominic Class one, made on the last days of House Vernius on Ix, and an excellent model.
Lady Anirul, Bene Gesserit consort to the Emperor and Kwisatz Mother, informed to the Sisterhood of the Amal project and its relation with the Spice and House Corrino, the Mother Superior sent Cristane to Ix, in order to investigate more about the origin of the Amal, and warned her that the Bene Gesserit had already lost an spy there, Miral Alechem, who had sent several reports of missing Ixian women, kidnapped by the Tleilaxu masters. Before reaching the planet, Cristane was disguised as a man, due to the fact that Tleilaxu woman weren't known, and because of her androgynous appearance. As soon as she reached the city of Vernii, she was discovered by the Ixian rebel C'tair Pilru, a Vernius loyalist, who took Cristane to his headquarters, and both worked as saboteurs in the city. During weeks they worked together, developing a sincere friendship, and killing Tleilaxu servants after questioning them. Cristane and C'tair even shared a kiss, but he had in his mind all the moments he shared with Miral, his lover and partner.
Finally, Cristane, obeying the orders of the Sisterhood, decided to enter in the Tleilaxu Laboratory to look for Miral Alechem and the secrets of the Amal. C'tair disguised her as a Tleilaxu servant, and her Bene Gesserit powers let her confuse the scanner in the entrance of the building, just for some minutes. She discovered in the laboratory that Miral Alechem had been turned into an Axlotl tank, and that many other women suffered the same horrible conditions. Cristane put an explosive disc on Miral's tank and while she tried to escape, she was discovered by Sardaukar guards, who pursued her while she was throwing explosive disc at them. Finally, a shot hit her spine and paralyzed her. The Tleilaxu Master Hidar Fen Ajidica recognized the make-up used by Cristane, and when the guards tore her cloths, they discoverd Cristane's slim figure. Then, the explosive discs activated, and all the pavillion of experiments was completely burned. The furious Ajidica ordered that Cristane shall be questioned and then turned in an Axlotl tank, replacing Miral's place.
While still conscious, Cristane ordered her body the analyze the substance in the Laboratory, and discovered a similar smell to the Spice, but definitely it wasn't Spice, but other thing, and then, she discovered the diabolical Tleilaxu system, which she wish she had never discovered.
When Count Hasimir Fenring appeared on Ix to affirm Ajidica that his Amal was a failure, and that the project shall be canceled. Ajidica showed the Count his new Axlotl Tank, the Bene Gesserit Cristane. Fenring realized that behind the Bene Gesserit investigations on Ix was the hand of Lady Anirul, and then was threantened by Ajidica that the project shall continue normally.
During the Second Battle of Ix, Count Fenring provoked a fire that burned a big part of the Laboratory, included the bodies of several Axlotl Tanks, among them Cristane. At the end of the Vernius-Atreides reconquest of Ix, C'tair Pilru discovered that her two Bene Gesserit partners had been used for the project of the Synthetic Melange, which provoked the fury and rage of Prince Rhombur Vernius against House Corrino, who had hunted his family just because they wanted to break the Guild's control, and re-order the social organization of the Empire at their way.