A worthy conclusion to an amazing trilogy. After the heroic struggle for survival in Red Mars, and the covert war of Green Mars, KSR settles down to the messy business of governing a growing planet. A lot of reviews have criticized this book as a 600 page epilogue, but I thought that the story was all very present, all very live issues. KSR has a better gift for imagining future social and political conflicts than he does the vagaries of ground-to-orbit warfare and civil disobedience (or at least his fictional politics haven't been obsolesced as brutally as the revolutionary stuff). The water-rich, terraformed (seas, canals, Mediterranean villages, storms!) Mars is a delight to visit. The aging cast feel appropriately melancholy, and the new arrivals to the setting are a lot more relatable than the strange Zygotes of Green Mars.

The Mars Trilogy is a massive, ambitious, modern classic of SF.

***UPDATE from December 19, 2012, for HUGO REREAD PROJECT***

If Red Mars was about finding Mars, Green Mars about becoming Martian, Blue Mars is about living with the consequences. Mars is now independent and mostly terraformed, the Martians trying to make their fragile government work, while hoping that a massively overpopulated Earth doesn't take them down with them. The characters are again the First Hundred, now pushing into their second century, and dealing with the consequences of such an unnatural life: memory that no longer works, habits of thought becoming psychological canyons, the ancient feud between 'Green' terraformer Sax Russell and 'Red' aerophile Ann Clayborn and its resolution. This isn't so much a novel as a linked anthology, and many of the stories feel like repeats--same characters, same plots, similar points on ecological responsibility and co-op economics.

The first half of the book is a slog through constitution-writing and a trip to Earth that goes nowhere. Only halfway through does Blue Mars find its pace, with Nirgal catching up with a band of feral hunter-gatherers, who wander the land hunting with thrown weapons and harvesting orchards before brief spurts of shopping and drinking in town. The story then follows the only new character, Zo, daughter of the power-hungry Jackie Boone and a diplomatic enforcer for Mars First trying to unite the scattered minor worlds into an alliance against Earth, and then returns to the aging First Hundred, living relics wondering at the world that they made and their place in it.

The sheer mass and momentum of the Mars Trilogy is impressive, but in the end I feel like it's too didactic, to in love with landscapes and ideas rather than people. KSR ends on the thought that it is better to think that you left your children a new Golden Age, rather than having squandered their birthright (ouch. very ouch), but I was left unsatisfied by both the retrospective and re-creative aspects of this concluding volume.