Lord John and the Private Matter by Diana Gabaldon
This is Book 1 in Gabaldon's Lord John series. This started out as a off-shoot novella alongside the Outlander series. The novella became a novel and then it became a series in it's own right.
It isn't quite as engaging as the Outlander series but I wish that I had read this book in it's proper place with the Outlander series. It's weird to go back in time, so to speak, and try to remember what was going on in the Outlander books at the time of this book.
I enjoyed the historical information about the LGTB community at the time and I will keep reading these books and see where they take me.