I found this book unsettling for a number of reasons.
First, it is out of date as far as the world scene goes; we now have detente with Red China. You have to remember how things were in 1970 when the book was written. The Cold War was raging. The war in Vietnam was at its peak. Nixon had not yet been to China. Watergate was just an apartment complex in Washington D.C. You have to remind yourself as you read that this book was written 45 years ago and everything has changed. It was hard to let go of what has gone between and think about the story in terms of the 1970 mindset/(paranoia?).
Second, I'm so used to his Dortmunder books--the gang that couldn't shoot straight-- that I'm not sure if Westlake was being tongue in cheek here or trying to write a hard-boiled spy thriller (is that the right genre?). Maybe it is a little bit of both.
So, maybe 'unsettling' is the wrong word, but I don't have a better word for it.
The hardest part was actually reading it as opposed to listening to it. It took me almost two weeks to get through it while I can get through an audio title in a couple of days. My reading skills are not what they used to be. I can't remember from one day to the next what I read or what is going on in the story. (But, I got this Kindle and I am damn well going to use it).
But, I do like Westlake. He writes with a bit of a twinkle in his eye. It is easy reading but well written.
So, I'll give 3 and half stars.