Darwin came tantalisingly close to understanding them, 20th-century eugenicists obsessed over them, and with modern science, we are poised to control them as never before. Genes are a constant source of fascination, yet ignorance and misunderstanding plague almost every public discussion of their effects on our health and behaviour. How useful it would be, then, if there was a clear, accurate, and up-to-date pop science book on genetics, a book that recounted the history of genetic science and reflected on its implications for the future of medicine and society.