The plot becomes rather predictable. Instead of finding myself sitting in the car wanting hear more, I found myself procrastinating. Finally I forced myself to listen to the last hour. I won't give away the end, but I will say that it did not change my overall disappointment.
I haven't seen the movie so I do not know if they changed anything significant. Unfortunately, this is the first PD James book I have read and I do not feel inclined to read more. If any of you have read more PD James, please leave a comment comparing this to her other work.