I picked up this book because I've always loved mysteries, this one promised to be a mystery and also qualify as decent lit., and because I loved the cover.
Unsworth is obviously a very talented writer, and the amount of research that must have gone into this novel in phenominal. Even more impressively, it doesn't feel like research when you read it. I learned all sorts of interesting details about Medieval life and culture in general and Medieval theatre in particular, and I got to learn all these things while being primarily engaged by a fascinating story, and a group of well-drawn characters. They were all good. Stephen, Tobias, Straw, Springer, our narrator, the marvelously real Nicholas, and particularly Martin, the leader of the Players, and Margaret, the marginalized member.
The mystery itself wasn't particularly difficult to discover; however, the tension of the book was steadily built, and the threat that the Players constantly felt seemed very real.
Unsworth also excels at description, and passages describing the bitter winter weather, and the arrival of the knight, are excellent.