I am just a tad bit obsessed with Ruth Rendell right now, so you will see quite a few posts with her books. I think there are almost 80 of them, maybe more if I count short story collections, uh oh...... I will get around to the other books I planned to read at some point I hope.
Anyway, this book was one of her earlier ones, published in 1968, and is the story of Susan Townsend, living with her son Paul, recently divorced from her husband. Susan has the misfortune of finding the bodies of her neighbor Louise and her alleged lover, in Louise's house. Louise's husband Bob, begins spending a lot of time with Susan, who start to realize that all is not quite right with Bob. Very good book, although the early style is much different from some of the later books that I have read.