As this is Alys Clare, you can expect 50% histmyst and 50% woo woo, which is a good description of this book.  On the one hand you have the mystery of knights up to no good and murders in Chartres Cathedral, and on the other you have the mysterious Joanna and her offspring, a man turning into a bear and a magical statue of a pagan deity.  Clare shows her talent for description when Josse and his companion explore the castle where the deviltry is purported to be going on; she gives a truly eerie description of a place with a terrible atmosphere that is almost tangible.  I don’t confess to know much about witchcraft in the 12th century but am sure that it wouldn’t have been quite as New Age as the practices described here.  Clare describes an England where, although most people are Christians, pockets of pagans lurk here and there, which seems more akin to how it must have been over a hundred years earlier.  But this does not spoil a good story and this is a good story with plenty going on and all sorts of surprises, many of which I did not see coming.  If you like a bit of woo woo with your whodunits then this series certainly delivers both.