Born on the planet Arrakis eight months after her father's death, she possesses the full powers of an adult Bene Gesserit Reverend Mother.

"[6] An adult Alia is described by Herbert in Dune Messiah: Her features lay exposed—blue-in-blue "spice eyes," her mother's oval face beneath a cap of bronze hair, small nose, mouth wide and generous.

[8] William Touponce explains, "Alia is the archetypal virgin-harlot, a Reverend Mother without motherhood, virgin priestess, witch, and object of fearful veneration for the superstitious masses".

[9] In Dune (1965), Alia is born a full Reverend Mother when she is exposed to the Water of Life (the bile of a drowned sandworm) in the womb as Lady Jessica undergoes the spice agony.

Jessica, despite her awareness of this likelihood, brings her baby to term, and Alia slowly learns to control the powers she has been granted as Reverend Mother and sister of the Kwisatz Haderach.

Mature far beyond her four years, Alia escapes during the final battle of Arrakeen, but not before pricking her grandfather, Baron Harkonnen, with a deadly, poisoned gom jabbar, also revealing her direct lineage to him in the process.

Afterwards, she wanders the battlefield of Arrakeen killing fallen Sardaukar and Harkonnen soldiers with a crysknife, earning her the holy epithet "St. Alia of the Knife.

"[4] Alia uses her limited prescience in a unique way, projecting thoughts and images into the mind of the horrified Imperial Truthsayer, Gaius Helen Mohiam.

"[11] The character is further explored in 1969's Dune Messiah through her relationship with the ghola Hayt, who is Paul's teacher, Duncan Idaho, brought back from the dead by Tleilaxu means.

[7] Alia gives the order to Fremen leader Stilgar to execute the Reverend Mother Mohiam and Spacing Guild Navigator Edric after the failure of their conspiracy (with the Tleilaxu Face Dancer Scytale and the Princess Irulan of House Corrino) to seize the throne from Paul.

[7] Touponce notes that "Alia will come to sexual maturity in [Dune Messiah] and discover an ascendant desire for a mate and political power.

Falling under the influence of the persona of her deceased grandfather, the Baron Harkonnen, Alia abuses her powers as Regent and becomes a ruthless tyrant.

[6] In the Brian Herbert/Kevin J. Anderson novel Hunters of Dune (2006), the Face Dancer Khrone manages to restore the memories of the Baron Vladimir Harkonnen ghola.

The Baron is displeased to note that Alia's voice haunts him in his head, somehow in a reversal of the influence he had over her while she was in the throes of Abomination in Children of Dune.

[20] The casting of Anya Taylor-Joy in Dune: Part Two as an adult Alia in a cameo appearance was kept secret until the February 2024 film premiere in London.

In a moment of exact parallel between her child self in the Dune miniseries, Alia reaches up to touch her mother's tears, tastes them, then whispers, "I want my brother," before joining him in death.