This was exactly what I was looking for -- an engrossing science fiction story with enough smarts in it to make you think a little bit. It's a diversion with a kick to it.
The story is told in two interwoven narratives, one of a mission to a mysterious and very large object, the "Matryoshka", that appears in Earth's solar system without warning and without communication. That story is told as a recollection by the main character, Dimitri Ivanov, who also tells his own story, in present tense, now that he has returned to Earth from that mission.
As in other of his writings, the author, Alastair Reynolds, brings a darker, pessimistic feel to the story. The Matryoshka isn't just an unannounced visitor -- it has a message for us, and that message is unsettling to the powers that be. I'm not giving away anything here -- that much is apparent from the beginning. But Reynolds has some surprises in the plot twists that make the story more than just another dystopian science fiction story.
All in all, I was swept along. This is a short book -- in fact, it is labeled a "novella", although published on its own and at the cost of a "novel". I have no complaints. If the story is good, that's what I paid for. And that's what I got.