This is about the adventures of one Freya Nakamichi-47, a class D escort developed by Nakamichi Heavy Industries, trained by PeopleSoft to the specifications of Hentai Animatics. In short, she's a femme-bot - and obsolete since mankind (and most of the biosphere) went extinct.
While mankind is extinct, the civilization rolls on thanks to the synthetic servants of mankind. They've gone to accomplish some of the dreams of humanity - building cities on Luna, Mars and beyond, an orbital beanstalk on Mars, mining the asteroid belt, beaming power from Mercury and vast STL starships.
The major problem is that the androids that succeeded mankind think and feel and are bound by conditioning and programs. Another is that the governments still exist (or at least their bureaucracies) and haven't recognized the situation and consider the androids to still be property - they can only be people (and own themselves) as limited liability corporation. And the situation is unlikely to change because no humans exist to create some sort of quorum and modify the laws. Thus an android can own another android, especially if the second went bankrupt or didn't keep up its filings.
This has lead to massive class differences. A small minority of aristocrats that own (or otherwise control) almost everything and everyone. The slaves that the aristos own and a very small minority of androids that own themselves.
Add in that since mankind has gone extinct fashionable body plans have shifted to the slightly inhuman among the aristos. Oh, they're still humanoid, but either bishojo (think anime with big eyes, small mouths and weird hair colors) or chibi (dwarf with the above features and an oversize head). The first is dominant because they were the secretaries, carers and the like that got power of attorney and took advantage of the situation. The second are the same, but optimized for space exploration and human interaction (the cube square law drives here). Those that are indistinguishable from humans (like Freya) are deeply unfashionable.
And that's just the Inner System.
Into this, we introduce Freya. After an incident with an aristocrat on Venus, she needs to travel and is off on an adventure that takes her to Mercury, then Mars, the moons of Jupiter and the deep outer system.
Along the way, we readers get a cynical view of the political system (if you can diginify it with that name), space travel and its attendant difficulties (its deeply unpleasant even for folks that can enter hibernation or a slowed time rate at a flip of a switch), espionage and the basics of how thoughtful, empathic androids like her were created (answer: brain simulation, emulation and then modification) and then trained into compliance (you really don't want to know, but I'll say that the 11th birthday of Freya's template matriarch is really important), soul chips (memories that can be salvaged and shared from robots in a lineage) and soul dumps (experiencing said soul chips).
All in all, its pretty darn good. Like a lot of SF, the setting outshines the character, if only because Freya occasionally comes across a bit whiny. Beware - there is at least one stinker of a pun in there.
The book is a tribute to Robert A. Heinlein's Friday, as well as Isaac Asimov's robot stories, as well as golden age space operas set in the Solar System. But the tributes are suitably modern.
This is the story of a sex-robot turned espionage agent in a solar system where essentially all life has become extinct. It's an interesting idea --- such a robot has certainly become an obsolete item in such a place...
Stross' conceit for granting self-awareness and intelligence to such robots is the more-or-less direct copying of human neural networks onto non-organic brains, making these robots extremely human in their emotions and reactions. It's a fascinating look at how such artificial intelligences might one day interact.
But at the same time, I never really got into this book. The characterizations fell flat for me, and I struggled to stay interested. Stross has called this book his homage to Heinlein's "Friday", and sadly, it falls short of Heinlein's work. (Though Stross' technology is far more interesting.)
3 of 5 stars.