I love reading period mysteries. If they are really well-written and the author has done his/her homework and research well, they can be almost as educational and enlightening as they are fun.
And ~ I also love reading Old mysteries. Mysteries that are “period” because of when they were written: Agatha Christie, Margery Allingham, Dorothy Sayers to name a few. When these women wrote, there were no cell phones, computers and other conveniences of modern detection. Of course there was also racial and sexual exploitation. Sometimes language offends today’s ears more than murder because the murder is story, the language was real and the way society spoke then. They wrote “modern” stories, ones that fit their time. They don’t fit ours and so in their own way, they have become period pieces, reflective of a very different way of living and thinking. Most interesting.