If you've read his wonderful Dalziel and Pascoe series, you know Reginald Hill. He's a fabulous writer of nuanced mysteries. This is one of his early efforts and while it softly touches on the "spy" genre, it's worth reading because of his amazing rendering of the wife character. This same ability to write women comes out in the series referred to above, though the main characters are men. It's a quick, fun read and interesting especially if you like to see how writers develop their craft.