The Vanishing Man by Chas. Finch

Vanishing is another in the excellent Charles Lenox series set in London in the 1800s. Lenox is an amateur detective  and he has been hired by a duke to find a missing painting. Lenox is sure the duke isn't telling him all he needs to know but he starts looking for the painting and realizes there is a much bigger secret behind the theft. At the same time, his best friend, Lady Jane is trying to fix him up with the perfect girl. Alas, Lenox is madly in love with Jane herself, but she is married to a good guy, a military man who is off in other parts of the world for months at a time. And no other woman will ever live up to her. It's an engrossing series with interesting stories and likeable characters. One of my favorites is Lenox's valet, Graham, who is always impeccably tailored and ready to help Lenox solve the next case.