This novel jumps between two separate settings, Seattle, in the modern day, the city of Kalpa, the last bastion of civilization (and apparently of normal matter) in the universe, trillions of years in the future, when some vague, poorly understood chaotic force has consumed the rest of reality.
These two settings are linked by a pair of time-travel-esque magical plot devices. The first is that some humans in this final city of Kalpa have apparently been bred to be reincarnations of humans living in the distant past (i.e. modern day seattle), and will go into a dream-like stupor where their previous iteration's consciousness will briefly take over their body, and vice-versa with the protagonists in seattle.
The second is some sort of method of communication from some unexplained menacing force, probably from the future, which can extend human lives far beyond their normal range, and give them magical powers, in exchange for assistance in tracking down the protagonists and people like them.
The protagonists in Seattle have the ability to jump between parallel selves in parallel timelines, and to sense which timelines will be better or worse in their near future. They also each have a mysterious magic rock called a sum-runner, and although despite it being mentioned nearly constantly, the significance of these rocks is not made clear in the first half of the book.
This book draws heavily from the Dying Earth subgenre, which I am a fan of. Wikipedia describes it as hard sci-fi, which it most certainly is not. Wikipedia, again: "Hard science fiction is a category of science fiction characterized by concern for scientific accuracy and logic." Most of the extraordinary things that happen in the Seattle segments of the book are not explained scientifically, and I don't really think they could be. Trying to explain away magic powers as being the result of science of technology would, in this case I think, just sound like trying to convince the reader that these powers are not magic.
I persevered through about half of this book to figure out what I didn't like about it, and I think the answer is the air of hollow mystery, which pervades at least the first half. I've had this experience in some books in the past, where the most interesting thing about the story is the things that are kept from the reader. And when done well this does for a great story, but the problem with writing a mystery is that the answer to the mystery needs to be at least as good as the possible answers you've allowed to form in the reader's head. There's an art to handing out breadcrumbs of detail to the reader, giving just enough to keep the reader interested, all the while allowing the reader to slowly gain understanding of the underlying plot. If the underlying plot isn't all that interesting or well-thought-out, there isn't a payoff equivalent to the set-up, and it comes off as disappointing or anticlimactic.
Halfway through the text of this novel, I still have basic questions about the characters unanswered. For example: "what is this character's motivation," or "what is the importance of this MacGuffin that each of the main characters have," or "how does this character's action's work towards their overall goal." Many characters have some sort of unspecified plan which supposedly guides their actions, but they refuse to answer any questions about it. Having a character with mysterious motivations can be interesting, since the plot can revolve around uncovering why they're doing what they're doing. Having a whole cast full of characters with mysterious motivations is overwhelming. It starts to feel like the deliberate evasiveness of every non-protagonist character is contrived and silly. It almost comes off like they really don't know what they're doing, and desperately want people to think that they do. There's too many characters to focus on, with the result that any individual character's strange silence on their motivations can't leave much of an impression.
This isn't helped by the book's structure, which jumps between viewpoints and timelines in incredibly short chapters. You barely feel like you have time to get into the groove of a particular character's story before you are whisked away to experience the next one's confusion at the events which surround them. The reviews on the back of the book describe the novel as a thriller, which is I guess why chapters attempt to keep the action moving, but not enough time has been spent with the characters to make me empathize with them and care about what happens to them. It just jumps right into the action, with each main character either already being in a desperate situation, or being placed in one almost immediately. This also prevents the characters from stopping to think about what is going on, or ask for clarification on any points from people who supposedly know what is going on, or wonder someone who is supposedly trying to help them expects them to trust that person without any information about who they are or what they want.
If I'm about to do something, and a mysterious character says not to, I'm gonna ask "why not?" And if they give some garbage like "It will be made clear to you when you're ready" I'll tell them "It better be made clear to me right now, because otherwise I'm gonna do it just to spite you."
I think maybe this works into a life lesson as well. People who are working in your best interests and trying to help you won't keep secrets about your situation from you. If someone says they're trying to help you, and that you should trust them, but won't tell you whats going on or why they want to help you, then they probably aren't actually trying to help you.
The present-day segments and the end-of-time segments feel pretty disjointed. I don't know if they tie together in the second half, but at least in the first they're pretty tangential to each other. Present-day people do their thing, and end-of-time people do their thing, but neither group really has much of an effect on the other. Some characters in each are aware of their counterparts, but don't have involvement in each other's plots. This ends up functioning as two separate plots, both of which could stand on its own without any difficulty. I bet if you read just the present-day segments or just the end-of-time segments, you'd have a pretty coherent story until probably near the end.
It just kind of begs the question of why these two concepts didn't become two separate books instead of this one Frankenbook. It feels like I'm reading each of those hypothetical books, but switching from one book to the other every couple of chapters.
I don't want to be a total negative Nancy though, so I'll balance it out with some things I liked about the book.
I liked that the book was copyright 2008, but the symbol on the cover is copyrighted 1984. Both by the author Greg Bear. I'm sure there's a story here, I don't know what it is, but I like the questions it conjures up. Why did he devise the symbol so long before writing the book? Why did he need to separately specify that the symbol is his as well as the text of the book? Why was it important for people to know that the symbol has been his intellectual property for the last 30 years? I'm imagining Greg Bear scrawling the symbol on a napkin in the 80s, thinking it was genius, and then sitting on it for 24 years, waiting to write a book worthy of it. Its a weird and very evocative detail for them to mention on the edition notice, and I like that kind of thing.
I liked the Dying Earth setting, and the idea of most of humanity in the far future having converted themselves to some exotic form of matter, baryons, mesons, etc.
I liked the brief bits of history Ghentun brings up to explain how the Kalpa got into the state its in.
I liked the idea of world lines and people jumping between them and being hunted. I liked the idea of the hunters serving some higher power and being allowed to live forever as long as they served. It gave me a very RiceBoy-esque vibe, which I'm fond of.
In general I like a lot of the ideas of this book. It was just the form of presentation that got on my nerves, the "need to keep moving, no time to ask questions" form of storytelling. In my opinion its not very fitting for a book with big ideas like this one, because the strength of this kind of story is exploring those ideas, not rushing past them.
Overall I give the first half of it 3/5 stars. It didn't hold my interest, as much as I wanted it to.