The two stories progress in the way you'd expect any murder mystery to progress, with, in one case, an explosion of suspects that are whittled down to one and clever police work in the other.
The thing is that this book doesn't grab you. You don't sit up and think "Phroar, this is getting good" at any stage. Don't get me wrong, it's not a "writing by numbers" book, but it's just not very exciting either.
I think that part of the problem is that Robinson wants to stick with Banks, when Cabbot (who is developing a drinking problem in this book) has the potential (I think at least) to be the more interesting character. Whenever you get to a point where Robinson has a choice between making her more interesting or wimping out and making her needy, he opts for needy every time. I personally think this bout would've been much better had Cabbot made some more interesting decisions when she had the chance.