The Hidden City by Charles FInch
This is the newest in the excellent Charles Lenox (Victorian London PI) series. When the story opens, Charles if recuperating from the serious injuries he sustained during a visit to America. He gets a letter from a servant who used to work for his family, asking for his help. She thinks someone has been trying to break into her house, but the police won't take her seriously. Charles decides to investigate and realizes that someone HAS been trying to break into her house--but he can't figure out what they're trying to steal. The investigation has him wandering all over London gathering clues and leads. At the same time, on the home front, Charles is dealing with the arrival of his cousin Jasper's daughter Angela and her best friend Sari, recently arrived from India, after Jasper's death. And Charles is dealing with his beloved wife's decision to become a suffragette, which is causing tension between them. As always, Finch tells a good story and it's always ...