I agree with the reviewers who noted that the book was well-researched, but still unsatisfying. I gave it an extra star precisely for that research, but that shouldn't imply it's worth reading. Because unfortunately, it isn't.
Matteson needs to go back to some basics and learn how to write characters. Charlotte Graham is entirely unbelievable and the plots are incredible, even by cozy standards. As much as I wanted to give her extra points for the clear research efforts, I just couldn't. My credulity as a reader was constantly being strained to the breaking point.
Skip this one, unless you're really bored.