A group of people “preadapted” to danger and stress have been recruited to run a power station at the bottom of the Pacific, their bodies altered through surgery and chemistry and implants to let them swim and breathe water at deep pressure. The first sign that something is wrong is that some of them go missing, while others turn to violence. But that much was predictable. What management didn’t expect was that they would be so dramatically changed by their environment that their own humanity would come into question. Or that other inhuman creatures were lurking. Watts’ propensity for creating apocalyptic scenarios is unparalleled, and this is no exception. The book moves in short, almost jittery chapters that—combined with the deeply disturbing paths the characters follow—makes for a discomfiting read. But I couldn’t put it down.