It was a slow book for me to get into. I don't know, for once I am speechless on what to comment about this book. I did yet didn't get the whole part of going back into his memories every second or so chapter. Yes, it does give insight on their past but it also seems like that's there because the original story was too short when in just present time, and franctly there was little story when in the present.
I don't know why you would put an ending like that in this book with the idea that it is a solo book. It does wreck the ending but if there was a second novel (to be honest, compared to this one there wouldn't be much to write about in present day and we would just get more stories on the past) then this would be somewhat reasonable cliffhanger but not for a solo novel. It just leaves too much in the open without us as the reader knowing answers or background knowledge - any knowledge at all - on what is going to happen from what has been left hanging.