The Fiona Griffiths series

When the body of a young woman is found in an old 'dead house' - the annexe of a church where the dead were stored before burial in medieval times, it seems that past and present have come together in a bizarre and horrifying way. DC Fiona Griffith's investigations lead her to a secretive monastery in a remote valley, where she finds that the murder victim is far from the only victim of a dark and disturbing melding of modern crime and medieval religious practices.