Episodic, far-future yarn developed from short stories, from the veteran author of Starfarers (1998), etc. Before Christian Brannock dies, he uploads his own mentality into a computer, thus achieving immortality. Copies of him spread throughout the galaxy. Huge agglomerations of AIs, or nodes, begin the development of a galactic brain. Earth’s future inhabitants find they’re controlled by a node, Gaia, and can’t make war even if they want to. Millions of years later, Gaia severs her ties to the galactic brain. But since the solar system will soon be destroyed, the nearest galactic node, Alpha, wants to know whether it’s worthwhile expending considerable effort to preserve Earth. Alpha sends Wayfarer to investigate. Gaia creates an avatar, Laurinda Ashcroft, for Wayfarer’s avatar, Christian, to interact with while Gaia chats with Wayfarer. Another Wayfarer avatar, Brannock, goes exploring in a robot body. Gaia, however, is concealing things from both Wayfarer and Brannock: She’s been running simulations of alternate pasts and futures, “emulations” that result in great suffering for untold humans. She’s even re-created real humans and set them loose on the real Earth. When Brannock learns of this, Gaia attempts to subdue him. Christian and Laurinda, meanwhile, visit many emulations and become lovers. Lots of vivid vignettes but no discernible whole, with Anderson mostly struggling to define his concepts: “No human could have shaped the thoughts or uttered them.” Quite.