William Le Queux 
Seven Secrets 

A timeless whodunit about the unusual murder of one of London’s elite and the twisting and treacherous investigation to find the true killer. Despite wealthy old Mr. Henry Courtenay’s steadily declining health, his death comes as a shock to those around him. It was murder, Courtenay’s prim manservant exclaims, and he implores Dr. Ralph Boyd to find the culprit. The list of suspects appears to be short: Only someone who lives in Courtenay’s suburban London home could have gone into his room unnoticed. Could the murderer be one of the servants? Or perhaps Courtenay’s young wife-or her beautiful sister, with whom Boyd has fallen in love? Boyd is beginning to realize that in the Courtenay home, secrets abound at every turn and, as with all great mysteries, nothing is as simple as it seems. (Goodreads)