Joan Slonczewski is both a microbiologist (she is co-author of one of the standard textbooks in the field) and a science fiction writer. Her latest sf novel, MINDS IN TRANSIT, is a sequel to her previous novel BRAIN PLAGUE (2000), and overall the fifth novel in her Elysium Cycle (to which most of her novels belong). It would probably help to have read BRAIN PLAGUE before tackingly MINDS IN TRANSIT. We have a pair of planets with future technologies, the most important of which is that microbes are sentient, along with many artificial entities and systems. So the people in this world are continually negotiating both with one another and with the million microbes who inhabit them. There are evil microbes who take over their human inhabitants by manipulating their pleasure and pain systems, but most people get along with the microbes that inhabit them in a more or less symbiotic fashion. For instance, the main character Chrys is an artist, and her visual works are collaborations with the microbes within her. The novel mostly consists in all sorts of social and political interactions among the characters, including the microbial ones, and there is no clear line separating social interactions from political power moves. This may sound cynical, but the novel really is not so. The science fictional novum of intelligent microbes is really a way to dramatize how all life involves interactions among multiple life forms, all of which shape and are shaped by the physical environment as well as by one another. Interactions can exist anywhere along the spectrum from complete symbiotic mutualism to one-sided parasitic exploitation. And in fact, IRL our lives are profoundly shaped by such interactions, even if many of the partners (like the microbes that actually do live within our bodies) are not in actuality capable of language and conscious reflection. Slonczewski powerfully illustrates how the mutual web of life really works, through the extrapolative tactic of extended sentience. The plot, such as it is, is quite convoluted, but this makes total sense, given the ways that the book is depicting and making visible the sorts of connections and disconnections that all living beings are involved in. We are all — people, animals, plants, fungi, and microbes alike — involved with one another in multiple ways, involving both unit integrity and interconnections that mean that no unit is actually self-enclosed.