This is a very good piece of detective fiction from 1920's Great Britain. Even if you weren't a fan of the genre, you would be after reading this. It is an excellent psychological mystery even though it has very little of the breath-taking action characteristic of most mysteries. It pulls you into the plot gradually until you finally can't put it down. It all starts with a mysterious photo of what appears to be a man attempting to shoot another man that is found by our detective, James Flint, in one of his library books. From here we are taken on a journey to exonorate an innocent man and to identify a killer.