The Dark Forest

Readers who haven’t read (or haven’t recently reread) 2014’s The Three-Body Problem will feel disoriented at the outset of this sprawling hard SF novel. In the prologue, an ant and a spider overhear Dr. Ye Wenjie, an astrophysicist, suggest to astronomer-turned-sociologist Luo Ji that there are “axioms of cosmic civilization,” a neat variation on Asimov’s psychohistory. This scene epitomizes the book’s biggest flaw: clever ideas lost in often didactic prose. Before the notion of a cosmic sociology can be further developed, Liu shifts gears to present a dialogue between an alien intelligence, the Trisolaris, and the leader of the Earth-Trisolaris Organization, about the distinction between thought and speech. The Trisolarians pose a significant threat to humankind, which triggers very different responses on Earth, ranging from the Escapists, who believe that flight is the only option, to the formation of a Planetary Defense Council. The upbeat ending sets up the concluding volume, but not everyone will have the patience needed to get that far. (Aug.)