Cutting edge research on human reproductive biology in the hothouse atmosphere of Silicon Valley is the focus of this last installment in Carl Djerassi's pioneering "science-in-fiction" tetralogy. Renu Krishnan is an Indian-born, American-educated scientist who discovers how "No" (nitric oxide) can help men with erectile dysfunction, which describes the research behind Viagra. At the same time, her husband, Israeli scientist Jephtah Cohn, develops a new approach to ovulation prediction, which again is based on current medical research. Djerassi brings back many characters from his three earlier novels for a satisfying conclusion in the high-stakes world of biotechnology.