It is the twenty-third century. Herb, a young entrepreneur, returns to the isolated planet on which he has illegally been trying to build a city-and finds it destroyed by a swarming nightmare of self-replicating machinery. Worse, the all-seeing Environment Agency has been watching him the entire time. His punishment? A nearly hopeless battle in the farthest reaches of the universe against enemy machines twice as fast, and twice as deadly, as his own-in the company of a disarmingly confident AI who may not be exactly what he claims…Little does Herb know that this war of machines was set in motion nearly two hundred years ago-by mankind itself. For it was then that a not-quite-chance encounter brought a confused young girl and a nearly omnipotent AI together in one fateful moment that may have changed the course of humanity forever

In this uneven sequel to Ballantyne's Recursion, humans can live on as digital clones or "personality constructs" of themselves, leading multiple lives in the numerous matrices of 23rd-century cyberspace and enjoying equal rights with their physical compatriots. Like the first series entry, this novel interweaves several story lines concerning the dubious existence of an omnipotent artificial intelligence known as the Watcher, who controls the Environmental Agency, the organization in charge of all aspects of the digital and physical worlds. With the help of a geisha-garbed agent (and her numerous digital clones), a woman seeks asylum from a cyberspace killer determined to repeatedly torture and murder her digital incarnations. Meanwhile, on a remote planet in the physical world, a social worker investigates a series of artificial intelligence suicides that may hold apocalyptic implications. Though Ballantyne writes with engaging authority about high-concept technological novelties, the three protagonists often come across as self-parodies, spouting clumsy and predictable exposition that grinds the tale to a halt during what would otherwise have been memorable climaxes. This is a shame, because the inventive plot, which interweaves such staples of the genre as dilemmas of free will, memory and identity, contains enough mind-bending twists and double-crosses to satisfy most cyberpunk fans. After rescue from a trap set at work, Helen is displaced in time. She is now a personality construct, or PC. Her caseworker, Judy, tells her that PCs have the same rights as atomic humans but that for the past 70 years, Helen has been running illegally on the Private Network for the pleasure of customers playing powergames. Helen vows to help Judy hunt down the head of the Private Network. Meanwhile, Justinian, a therapist for troubled PCs, is assigned to an extragalactic world where a several AIs have committed suicide for no apparent reason. It's a strange world of Schroedinger boxes, which become fixed in location only when someone looks at them, and unbreakable black velvet bands, which appear out of nowhere and shrink away to nothing. As Helen and Judy discover Private Network secrets, and Justinian slowly unravels the ever-stranger AI suicides mystery, their stories converge upon a terrifying conspiracy to hide the truth of an outer universe. Ballantyne's pacing and world-building skills make this all engaging and a bit creepy. Regina Schroeder