Taking the protagonists on a journey outside their usual realm is always a good idea to keep a long-running series fresh, and this book is a good example of it working well.  The historical backdrop of warring tribes, uneasy churchmen and changing ideals makes for a compelling story; and although this is one of the longest books in the series, it carries its length admirably.  There is not only a murder to solve but also mysterious disappearances and suspicious local characters, making several cases in one that are intertwined a la Judge Dee.  Reminding the reader that this is part of a series as well as a complete story, several familiar characters also appear; and there is a chance to see the protagonists performing when hampered by foreign laws and rules. This is a period usually overlooked by historical novelists and it is hard to see why as there is just so much to write about.  Enjoyable as always.