Home by Nightfall by Chas. Finch

 This is part of the excellent "Charles Lenox" series set in Victorian London.  Lenox and his investigation agency--along with everyone else in London--is looking for a missing German pianist who vanished mid-concert. Lenox takes a break to spend time with his brother Edmund on the family estate because Edmund's beloved wife has suddenly died and Lenox is worried about his brother. While out in the country, Lenox gets another case involving a missing bottle of sherry and a strange drawing on the doorstep of a local insurance man. Then the mayor gets attacked. And there is a series of thefts. Lenox begins to wonder if all these events might not be related, so he and Edmund begin their investigation. eventually, he ends up back in London, again on the trail of the missing German.

If you like this series, you will like this book. The main characters are amiable and the mysteries are engaging.