Julie Czerneda is not an author whom I follow regularly. But she has been on my radar ever since reading A Thousand Words for Stranger several many years ago. I read Survival, the first book in the Species Imperative series, when it came out and enjoyed it well enough. By the time Migration, book two, came along, I was reading other things and never found the time or inclination to continue. Recently, DAW issued the entire series in this omnibus volume, offered by the Science Fiction Book Club, and – the stars being favorable – I decided to complete my reading.
A brief summary: Sometime in the future, Earth has become a member of the Interspecies Union, a galaxy-wide association of aliens held together by the Sinzi, who control the transect technology that makes FTL travel possible. While interspecies relations are never easy, the situation appears stable and there are no threats on the horizon. In the Solar system, heavy industries and much of the population have moved off Earth, allowing the planet to begin recovering from the ravages of the Industrial Age.
Things are never so simple, of course; otherwise we wouldn’t have a novel. Along one of the transects that pass through the Solar system, there is a region of space called the Chasm, where every potentially life-bearing world has been scoured of all organic life. No current space-faring species knows who, why or how this occurred but recently similar scourings have been happening on worlds along the transect.