I bought the Kindle edition of this book using the credits that Amazon gives Prime Members when they choose slower shipping on physical purchases; do enough of those, and it adds up! I also checked the audio CD edition out of the local library and threw it on my fitness watch and so made pretty fast progress on this flipping back and forth between the two media.
The story as it goes is an interesting enough idea, though time travel is almost hackneyed by this point, and it's all too easy to make illogical jumps (more on that later). But yeah, interesting story with interesting characters. I read it because Neal Stephenson cowrote it (who is Nicole Galland?). I found it to be mediocre by Stephenson standards, but that that's a lofty expectation to judge against. It's really fine.
It's well written, and although I am not an expert in any of the time periods that the characters visited, I liked the details that were added there; it seemed to me that the authors did their homework.
I can't think of any other time travel stories that relied on the concept this book calls "strands" - a tie in to the many-worlds interpretation of quantum mechanics. It was a cool way to explain some things, though it didn't come without its own hitches...
Why can only people travel through time - not even the fillings in their teeth could travel with them...
The other magic that witches can perform should have been developed more.
There were some rather large inconsistencies that you just had to ignore. Like, when the past changes, why do people that were merely involved in the greater scheme but not actually time traveling themselves not have their memories changed? But others did? I mean, it was sorta funny when the name for the Pentagon changed, but it just didn't add up.
Lastly, look, I realize now that this was meant to be the first book of several - but they didn't finish the story. I didn't know until I was done with it that there are other books to follow - and from what I can tell Stephenson isn't writing them.
I didn't hate it, but I had to just grin my way past some holes and inconsistencies and otherwise unexplainable things when they happened. Not Stephenson's best work, but it was still alright. I give it 3 stars out of 5. If you're thinking of reading this only because you like Stephenson, maybe stay clear - but if you just want something to read, you could do much worse.