An interesting mix of post-apocalyptic SF and alt-history detective story. This dates from 2004, and isn't quite in Reynolds' normal vein; as a result, it has quite a different feel from his space opera, although there's some overlap in themes with his more recent work (e.g. the Slasher/Thresher tension). A tidy story with an impressively wide scope; recommended.
ISBN 9780575082496.