Century Rain is a space opera/noir/alternative history mash-up that echos Reynolds earlier work in its combination of post-Singularity speculation and end of the world/galaxy/university machinations. The book opens a few hundred years in the future. Earth has been rendered lifeless by a nanotechnology plague. Humanity survives in two factions: the Threshers, who are regular humans who have turned their back on nano-tech and actively avoid research any technology that might lead to it, and the Slashers, who see the destruction of Earth’s habitat (and all the people living there) as a life lesson and embrace nanotech.
The Threshers discover a wormhole to an alternative Earth circa 1959, in which World War II was never fought, and technology is stuck at 1960 levels. The nature of this alternative Earth — is it truly the past? is it a reconstruction? an alternative reality? or something else entirely? — is unknown. An archeologist is sent into this “Earth 2” to learn more about the world … and recover artifacts left behind by her now dead predecessor. But was that fallen archeologist’s death an accident … or something more sinister?
It’s a good read — not nearly as galaxy spanning as his earlier work, but still engaging, with a good mix of mystery and science fiction. My only complaint is that the real mystery — the nature of the alternative Earth, not the murder — is left unanswered. The book was released in 2004, so I doubt a sequel is coming, but I’d happily read it if it answered that question.