Richard Powers’ latest novel, Playground (2024), foregrounds two realms of scientific issues in the public sphere—the oceans and AI. In that sense, it looks in large part like a follow-up to two of his previous works: The Overstory (2018), an analogous treatment of the environment as represented by forests, and Galatea 2.2 (1995), which describes the creation of a very early version of an AI. Here, the focus appears to be an elaborate scheme to fill the South Pacific with floating cities, to allow wealthy people to escape the tribulations of the real world, with the development of a Facebook-like app as a secondary theme. The exposition proceeds via three narrative streams: the stories of a software engineer, a pioneering deep ocean explorer, and a tiny Polynesian island designated as the home base for the floating cities project. As the plotlines evolve, the reader is led to anticipate how the pieces will connect up—until a totally unexpected plot reversal near the end forces a drastic reappraisal of what the book is primarily about, suggesting that despite the elaborate portrayal of risks to the oceans, AI may, in fact, well prove to be the greater threat.