I just read a historical mystery series by Rennie Airth. There are only two, so far, in the series, but I hope there will be more. The first, River of Darkness, is set in the early 1920s and the second, The Blood-Dimmed Tide, is set in 1932. Both follow Scotland Yard as they track serial murderers in rural England. I like the fact that both books are written from multiple points of view, although I think this is more seamless in the second book. I have read a great deal of World WarI fiction recently, and this is a great addition to my list. They are dark books, especially the second, in which the Nazis are coming to people's attention and mothers fear for 10-year old boys.