"A Play of Heresy" is a historical mystery set in 1438 in England. This is the seventh book in this series, but you can understand it without needing to read the previous books, and it doesn't spoil the mysteries in the previous novels.
While the mystery was enjoyable, I found the historical information extremely interesting. The author clearly did her research, but I never felt like I was being lectured to or given information not relevant to the story. The rich historical detail brought the story alive in my imagination and included how plays were run, how official murder investigations were done, and information about the Lollard's beliefs.
The "whodunit" element was guessable, though there weren't many clues. It's more like how a real murder would be solved than a clever puzzle-mystery. The characters were varied and had just enough of a human element to make them interesting even though we didn't get to deeply know them. The suspense was created by the mystery of whodunit and wondering if they'd be able to pull off a play that was poorly written and had few good or experienced players in it.
Though Lollards were viewed as suspect, Joliffe was not highly critical of their beliefs. (As in, people who share some of the Lollard's views aren't going to feel alienated by the storyline though it stays true to the beliefs of the time.) There was no sex. There was a very minor amount of explicit bad language. Overall, I'd highly recommend this interesting and enjoyable novel.
I received this book as a review copy from the publisher.