Near-future biological thriller, very much in the vein of Bear’s previous outing, Darwin’s Radio (1999). Researcher Hal Cousins, close to achieving human immortality, studies primitive bacteria and DNA, and embarks on a dive in a bathysphere to capture the organisms he needs. During the dive, his companion, Dave, inexplicably turns homicidal, obliging Hal to knock him unconscious. When the sphere surfaces, Dave struggles out of the hatch and vanishes into the sea. Aboard the mothership, too, there's murder and mayhem; later, when Dave's body is recovered, Hal comes under suspicion of murder. His wealthy backer dumps him, and his twin brother Rob, also a biology researcher, turns up dead. Then, the mysterious Rudy Banning brings a package of information from Rob. Hal learns that Soviet genius microbiologist Maxim Golokhov discovered back in the 1930s how to use bacteria to control human behavior. His program, Silk, apparently rejected by post-Stalin leaders, came secretly to America and spread its means of control all around the world. Banning, a historian, ran afoul of Silk and was sabotaged by them—but is that all he is? Rob's ex-wife, Lissa, shows up—but is she a Silk operative? Is Golokhov still alive? Why is Silk preventing Hal and others from perfecting the immortality treatments?
Bear whips up a marvelous froth of doom and paranoia; his ideas are frighteningly plausible, and the whole thing clatters along at a smart pace. But where it's all going not even the author seems to know, and the upshot is both baffling and inconclusive.