Century Rain
by Alastair Reynolds

Twenty-third-century Earth is an uninhabitable wasteland overrun by rogue nanotechnology. When archaeologist Verity Auger, studying the relics of twentieth- and twenty-first-century Earth, is accused of reckless endangerment after a child in her care nearly dies, shadowy government forces within her department offer her an out in the form of a mission to retrieve information from somewhere where her knowledge of the mid-twentieth century will be useful. Not until she is well underway do they inpart that her destination is an ALS (anomalous large structure) at the end of a wormhole in which 1950s Earth, slightly changed, is preserved. At that other end of the wormhole, Wendell Floyd is a Parisian PI working a case that gets stranger and more dangerous as he and partner Custine uncover the evidence, which is precisely the information Verity must fetch. The threads come together in a race to save both Earths from extremists, in which Verity and Floyd frantically search for the significance and location of three metal spheres. Reynolds blends noirish sleuthing and hard sf remarkably well.

Other Books by Alastair Reynolds

Absolution Gap

Redemption Ark