Sequel, as predicted, to Kress’s wonderful alien-contact yarn Probability Moon (2000). Humanity is at war with the ruthless, xenophobic, uncommunicative alien Fallers. Planet World’s furry, intelligent humanoids somehow “share reality”: they think and react alike, or suffer the consequence of blinding head pain. Also on World reposes an ancient artifact, a relic of some vanished race, that can generate a shield impenetrable to directed-energy weapons. On another setting, the artifact causes heavy radioactive elements to explode. And, by manipulating probability, the artifact gives rise to the Worlders’ shared reality. A second expedition to World, led by the masterfully diplomatic Colonel Lyle Kaufman, includes genius physicist Thomas Capelo—he’ll study the artifact—and gene-modified Marbet Grant, supernaturally capable of interpreting body language and involuntary cues, to interrogate a captured Faller. Though the Fallers already possess the shield against energy beams, Capelo makes no progress toward understanding the physics behind the device. Marbet makes little headway in communicating with her captive. The artifact, Capelo learns, might protect the Solar System against Faller attack—but if they remove the artifact from World, the inhabitants’ shared reality will collapse, along with their civilization. Then Marbet shows her Faller a model of the artifact, for which treasonous act she’s arrested and thrown into the brig—leaving all Lyle’s plans in ruins.
Kress’s always-excellent characters wrestle with a splendid array of puzzles and problems, human, alien, and scientific: another resounding success for this talented, sure-footed writer.