One of the Cold War’s more striking perversities never made it to public view. To hold their own in the nuclear arms race, both the United States and the Soviet Union built sealed-off cities to harvest plutonium. Brown focuses on the history of the two pioneering examples: the Richland community in eastern Washington State and Ozersk, in the southern Urals. The former was built early in World War II; the latter, toward the war’s end. Brown is a good writer, and she describes with precision the construction of the two sites (a difficult process in the U.S. case, an unbelievably horrid one in the Russian case), the hazardous occupations undertaken by their inhabitants, and the consciously contrived bubbles of socioeconomic inequality both places became. Over their multidecade existence, each pumped into their environs a volume of radioactive isotopes twice as large as that released by the Chernobyl disaster. They ravaged the health of their workers under the half-knowing eyes of superiors. But both cities offered their residents privileges they would not have enjoyed in any normal setting: tellingly, when given a choice to stay or leave, most preferred to stay and keep their material abundance at the expense of worrying about their health and that of their families.