The books follows one MacGregor Corson Gerswin, a man taken from Earth by the great and ubiquitous galactic Empire. Earth is a ravaged mess, torn by wicked storms and poisoned by centuries of pollution and destruction, and there humans are on the verge of extinction. Gerswin is a "devilkid", an orphaned savage living on the edges of the shambletowns, the last remnants of Earth civilization, gifted with vastly superior reflexes and strength, and cursed with biological immortality. He lives by reflex and instinct, stealth and theft, eking out a living as he has for an undetermined (but long) span of time since his parents were killed by the shambletowners. A scoutship of the Empire arrives and collects him as a specimen; subsequently, he is educated and civilized (somewhat) and placed in training for military service.
For the most part, the book is standard sci-fi action adventure stuff. It details Gerswin's rise through the ranks of the ISS Imperial military structure, and his efforts at operating the Imperial reclamation effort that seeks to restore Old Earth to what it once was, a largely goodwill effort begun due to it's popular appeal. It details his fight against growing Imperial disinterest in continuing the project in the face of the prohibitive cost and relative lack of gains, and his search for alternate answers that in the end lead to various revolutionary biological and ecological technologies that ultimately spell the end of the Empire and bring about it's downfall. As far as all that story goes, it's a good book and one I thoroughly enjoy.
For me, though, the greatest impact comes in the last portion of the final novel. Somewhere along the lines of two centuries or so have passed, and Gerswin's efforts have pretty much succeeded. He has built an enormous financial empire and through it has managed to develop and place in production various techniques for terraforming Old Earth. He has seeded Earth with the various spores and biologicals necessary to start the process, has tied up his various remaining loose ends in the Empire (consequently hastening it's demise) and has landed his ship for the final time on Earth. He has returned home, to a place that is vastly different from the place he left.
He has become a mythical figure, a god almost, to the inhabitants of Earth who recall the Captain of old who battled the landspouts and stone rains to bring about the reclamation. He plays out that almost god-like persona still, possessed with extraordinary abilities and talents which he uses as he can to progress the reclamation of Earth and the establishment of effective and non-oppressive society.
It's hard for me to describe the emotions I feel when I read this final part. My whole life, I've wondered what it would be like to live forever--or at least, for a long time--and this book offers a glimpse of what it might be like. For as time wears on for Gerswin, the weight of so many memories gradually builds. The people he has loved and fought for have all continually slipped into the dust of the past. Friends, lovers, even enemies... one by one, they vanish. He increasingly has trouble holding onto distinct memories; the faces of those he loved blur in his memory and he finds it difficult to separate them. Barriers that he erected as part of his 'civlization' are starting to crumble. Insanity looms.
In this last part of the story, Modesitt skims over perhaps 20 centuries worth of time on Earth, watching as the planet reforms, as society evolves, as once again the scattered remnants of the old Empire rediscover space travel and come to Earth searching for answers about the mythical Captain who figured so prominently in many of their own legends. All the while, Gerswin is there in the middle of it, still looking not a day over 30 years old, his past irretreivably slipping away from him and his mind becoming increasingly fragmented. He is held up and revered as a god, worshipped and secluded, and used by the locals for his strong genetic code and the attributes he can pass on to his children. It gives me a certain feeling of sadness that I really can not explain, to imagine what it must be like to be him, and to be so far removed from the times and places and people that the first 3/4 of the book describe and that you (as the reader) come to know and love.
Consider this as a recommendation. If you've never read this book, I suggest you give it a look. And if you've never read Modesitt at all... then what the hell is wrong with you, you sick bastard? [grin]