Every year, for ten years, a young woman died in Edinburgh. His final kill was the fiance of Inspector Tony McLean. He discovered the murderer quite by accident, recognizing a piece of fabric taken from Kirsty's dress. Now someone else is murdering young women in the same manner, but the Christmas Killer is dead; Tony went to his burial. There is also a string of arson fires in warehouses being renovated. One of the warehouse caretakers tells Tony the fires are the buildings committing suicide; they were all built by a secretive guild decades ago. Tony meets a priest who tells Tony that the Christmas Killer was a former librarian for a small order of monks who were charged with keeping occult texts out of the hands of the world and the monk fears The Book of Souls has been found and has claimed the soul of another person who is driven to murder young women. Very good writing and an interesting premise.