You start with the origins of a post-human tele-kinetic society, jumping forwards through its history in the second book, interrupted in the third by the arrival of a super-evolved inerstellar contagion which turns those it infects into a new and virulent species intent on infecting and converting all life it encounters. The last book is set in the far future as the two groups - alien hybrids and post-humans - struggle for supremacy.

As with all of Butler's work, I was acutely aware of her position as a pioneer, the first black woman to break through in a genre dominated by white men. For me she is a teacher as well as a storyteller. But her stories are confronting. There is murder, there is slavery, there is patriarchy, and these disturbing traits are not defeated in a feelgood happy-ever-after resolution. That is not the reality of a black woman in America in the 60s and 70s. The strength of Butler's work is in how her own reality is revealed in these very far-out science fiction and fantasy stories. They are set on earth, in part contemporaneous with our own history, but the real world is hardly mentioned, as the human society we know becomes a lesser species compared to the entities which replace it. But always I feel the author's presence, her voice telling a story which her white male contemporaries could never come up with.

You could read the "Patternist" books in the order in which Butler wrote them, but in this collection, the four novels are presented in chronological order based on the events described. It is at times uncomfortable reading, but compelling throughout.