As I read this book--which is totally excellent--I had an experience that I have had occasionally. A little less than half-way through, I said to myself "I know who did it." Not "I think I know." But "I know." Usually, when I have that reaction, I'm wrong. This time, I was right. And *knowing* that I knew whodunit made no difference to me in terms of wanting--needing--to get to the end of the book.