Halfway through, I was ready to declare it the best book I've read all year--fiction, non-fiction, any genre, whatever. The writing is masterful. The characters are so thoroughly well-written that you almost feel like you've met them somewhere. Even the characters that only appear for a few pages come across as three-dimensional, and you can never tell whether someone is going to end up being a major character or not until it happens or doesn't. The story premise, when I finally figured out, kind of blew my mind. I suppose you could argue that it's not that original and unique, but to me it came across that way, and I'm sure that part of that has to do with the way that Mitchell strategically dropped one juicy morsel of information after another every ten or twenty pages for the first half of the book or so, making you work to figure it out, and never for a second doing that my-readers-are-probably-idiots-I-better-spell-it-all-out-for-them thing that has ruined so many otherwise good books for me.
I suppose since it involves paranormal stuff, it counts as fantasy, but one of the coolest things about it was that it didn't feel like fantasy until suddenly, without warning, something fantastical was happening. (Which makes total sense, given that most of the book is written from the perspectives of characters who are just normal people going about their normal lives at first.) A lot of times when I'm reading a fantasy/sci-fi/spec fiction book, I feel like a lot of the lead-up is just kind of laying the obligatory groundwork of introducing people/places/things & waiting for something cool to happen. Not so in Bone Clocks. It's a good while before you get to the paranormal stuff, and by the time it happened I'd gotten so engrossed in the incredible writing and engrossing characters and their stories that for a second I was like, "Holy shit, what is going on!" Which, again, I think is the whole point, since that's exactly what the main character is experiencing.
The story spans sixty-some-odd years and is divided up into sections told from the perspective of several different characters, which gives Mitchell plenty of room to show off his character-writing chops; each character has their own distinct voice and personality, which is even more impressive when you consider how disparate some of them & their situations are. The only reason I'd downgraded to 4 (maybe 4.5?) stars by the end was because there are a few sections I can think of that to me feel like they suffer from under-editing. Which is not to say that the writing and storytelling is not still excellent; just that, in retrospect, some of the sections that I'm sure were intended to paint as complete and thorough a picture as possible of the time and place and current narrator felt a little extraneous & ultimately like they somewhat detracted from the main story.
But still--one of the most impressive books of the year for me, to be sure--particularly in terms of the strength of writing/storytelling and unique/intriguing premise--and since it sounds like most people don't even regard Bone Clocks as Mitchell's best work, I'm sure I'll be seeking out some of his others.