Cyberpunk guru Sterling's latest (Heavy Weather, 1994, etc.) is set in a 2095 whose pervasive but light-handed government allows everyone to do mostly as he or she pleases--food, shelter, education, health, and transportation are free--although we're given no indication of how this situation came to be, or how it all works. ``Post-humans''--ancient people rejuvenated by advanced techniques--pretty much run things; religious inspiration has been reduced to the effects of specific drugs; and it's illegal to feed vegetables to kids--in California anyway. Ninety-year-old medical economist Mia Ziemann attends the death of a former lover who bequeaths her a virtual-reality palazzo and a talking dog named Plato, whom Mia rejects. She decides to undergo a dramatic new rejuvenation that will turn her into a beautiful 20-year-old woman. But the new Mia also has a rebuilt brain and, calling herself Maya, rips off the medical monitors her doctors have emplaced in order to evaluate her treatment, and disappears. She ends up in Prague, there plunging into a bohemian whirl of sex, philosophers, designer drugs, artists, cliques, programmers, immortals, and young aspirants. And that, plotwise, is about it: We're watching people we don't care about do unsurprising and unedifying things amid interminable pages of chat. Some flashes of wit and some good ideas here and there, though nothing that Sterling hasn't touched on before, but the overall mood's difficult to evaluate: Intended maybe as a sly, wry joke, it's turned out merely earnest, ponderous, and elaborate.