The Xenogenesis trilogy is a one-volume novel entitled, "Lilith's Brood," in 2000 written by Octavia Butler (1989). It is composed of "Dawn," published in 1987; "Adulthood Rites," published in 1988; and "Imago," published in 1989. The trilogy is about an alien species, called Oankali, which come in three sexes, namely, male, female and the ooloi. The ooloi is a third gender that mixes and manipulates the genetic material and constitution of the male and the female. The first novel is about Lilith Iyapo, an African American woman, who is restored to life by the Oankali after a nuclear war that brings near extinction to humanity on earth. The aliens want to colonize the earth and fill it with Oankali-human creature hybrids. The second novel is about Lilith's half-human and half-Oankali son, Akin, who is kidnapped by the resisting and sterile human remnants. The third and last novel is about Lilith's full ooloi child, Jodahs, who integrates human and alien societies (Butler).
             Akin is an offspring, called construct, of five parents: a human mother, a human father, an Oankali father, an Oankali mother and a sexless ooloi (Butler 1989). On the outside, Akin looks like a normal human boy. The aliens rescue the rest of humanity at a very high price of a genetic merging of the human species with other races, which will alter all of them in the process. The new race emerges but there remain pure humans who resist the merger and the "salvation" offered by the aliens. The oolois sterilize these resisters so that they cannot reproduce the genetic defect, which drives human beings to destroy themselves. The resisters kidnap Akin, the most "human among Oankali children, and the Oankali allow this and allow Akin to decide if the resisters should regain their fertility and freedom, despite the risk and likelihood of their eventually destroying themselves again (Butler).
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