Since the Introdus in the twenty-first century, humanity has reconfigured itself drastically. Most chose immortality, joining the polises to become conscious software. Others opted for gleisners: disposable, renewable robotic bodies that remain in contact with the physical world of force and friction. Many of these have left the solar system forever in fusion-drive starships.
And there are the holdouts: the fleshers left behind in the muck and jungle of Earth-some devolved into dream apes, others cavorting in the seas or the air-while the statics and bridgers try to shape out a roughly human destiny.
But the complacency of the citizens is shattered when an unforeseen disaster ravages the fleshers and reveals the possibility that the polises themselves might be at risk from bizarre astrophysical processes that seem to violate fundamental laws of nature. The orphan Yatima, a digital being grown from a mind seed, joins a group of citizens and flesher refugees in a search for the knowledge that will guarantee their safety-a search that puts them on the trail of the ancient and elusive Transmuters, who have the power to reshape subatomic particles, and to cross into the macrocosmos, where the universe we know is nothing but a speck in the higher-dimensional vacuum.
By the year 2975, humanity has wandered down several widely divergent evolutionary paths. "Flesher" life is that which resides in a basically human body, though genetically engineered mutations have created communication problems throughout the species. In the "polises," meanwhile, disembodied but self-aware artificial intelligences procreate, interact, make art and attempt to solve life's mathematical mysteries. Then there are the "gleisners," which are conscious, flesher-shaped robots run by self-aware software that is linked directly to the physical world through hardware. Throughout, Egan (Distress) follows the progress of Yatima, an orphan spontaneously generated by the non-sentient software of the Konishi polis. Yatima gains self-awareness, meets with Earthly fleshers and, when tragedy strikes, becomes personally involved in the greatest search for species survival ever undertaken. Though the novel often reads like a series of tenuously connected graduate theses and lacks the robust drama and characterizations of good fiction, fans of hard SF that incorporates higher mathematics and provocative hypotheses about future evolution are sure to be fascinated by Egan's speculations.