Death Comes to Bath by Catherine Lloyd

In the last book, Major Robert Kurland was having some problems with the same leg that has been giving him trouble since Waterloo. His doctor (and family friend) recommends a trip to Bath to attend the healing waters. 

While there (along with Lucy's sister Anna and Penelope Fletcher who insists on coming along), they meet Sir William Benson. He is an irascible old man who seems to like no one in his family but really strikes up a connection with Robert. Of course, he will be the one to die. Robert is one of the first to find him and recognizes that, though he has appeared to have drowned in one of the baths, the man was really murdered.

Then comes a complex mystery including the man's own sons (really only two of the three are focused on), his two stepsons, the wife who looks so much younger than him, and their personal doctor. It's another mystery for Robert and Lucy to solve and they are going to have to solve some number puzzles in order to do it.

Three stars

Kurland St. Mary Mystery #6

This book came out January 28, 2020

Follows Death Comes to the School

Followed by Death Comes to the Nursery

Borrowed as audiobook from Audible Plus Catalog

Opinions are my own