In the background of what looks like a Panglossian techno-optimist novel, horrible things are happening. Most of humanity is wiped out, then arbitrarily resurrected in mutilated form by the Vile Offspring. Capitalism eats everything then the logic of competition pushes it so far that merely human entities can no longer compete; we're a fat, slow-moving, tasty resource – like the dodo. Our narrative perspective, Aineko, is not a talking cat: it's a vastly superintelligent AI, coolly calculating, that has worked out that human beings are more easily manipulated if they think they're dealing with a furry toy. The cat body is a sock puppet wielded by an abusive monster.

The planets of the Solar System are dismantled over time to form a Matrioshka brain, a vast solar-powered computational device inhabited by minds inconceivably more advanced and complex than naturally evolved intelligences such as human beings. This proves to be a normal stage in the life-cycle of an inhabited solar system; the galaxies are revealed to be filled with such Matrioshka brains. Intelligent consciousnesses outside of Matrioshka brains may communicate via wormhole networks.

https://en.m.wikipedia.org/wiki/Accelerando