Octavia Butler's premature and sudden death in 2006 has been very widely lamented, unhappily confirming her influence as a vital African-American and female pioneer in SF. Xenogenesis (retitled Lilith's Brood in 2000) is one of Butler's most important works, and comprises the novels Dawn (1987), Adulthood Rites (1988), and Imago (1989). The Notes cover Octavia Butler's life and work; the background and structure of the trilogy; (Black) SF in relation to race and gender; the tradition of dystopias; and the work in genetics that is central to the plot. The Annotations pay special attention to the feminist and racial critique of human behaviour, and to the scientific and religious themes that develop throughout the trilogy. Each of the three novels is dealt with book-by-book and chapter-by-chapter. An Essay, called 'The Strange Determination of Octavia Butler', considers the trilogy's two very different umbrella-titles and Butler's unusual use of genetic science, especially the discovery of mitochondrial DNA, to critique racial essentialism. It also argues for her use of cellular organelles as an metaphor for the African Diaspora driven by slavery. The Bibliography provides a complete listing of works by Octavia Butler, including short stories and work published on-line. It also has sections detailing works about 'Octavia Butler and SF' and 'Useful Reference Works'.