On one hand, it’s better than Saturn . At least this time around, we spend the entire book around Saturn and Titan, with a bit more exploration into the rings of the former and on the surface of the latter. There are essentially three plotlines: a robotic probe sent to Titan is refusing to phone home, someone has to go back to rings to verify that they’re alive, and it’s election season again–this time with Zero Population Growth as the main issue.
The first–going into the rings to collect samples to prove that they actually found life– doesn’t make the least bit of sense. There are arguments back and forth about who is going to go and how dangerous it is. But… why? Couldn’t they just use a probe? It honestly fills like filler, although there are some hints of something much bigger going on here, since the life in the rings now seems to be alien nanomachines (which: why? couldn’t they just be different?) After the artifact in the asteroid belt plotline doesn’t seem to have gone anywhere, there are at least hints on more of a story to tell.