I always enjoy the historical mysteries featuring Sister Fidelma and Eadulf, her Saxon husband. In this story, the couple are traveling to Autun in France where an historic church council is about to take place. one of the topics under consideration is whether or not the Irish custom of mixed houses for religiouse and marriages between them may continue. France at that time is a turbulent country caught between the Burgunds and their rivals, and Fidelma and Eadulf manage to arrive just after the murder of an Irish delegate has taken place. Their investigation solves not only that murder, but also unearths a slavery ring as well as a plot to overthrow France's king. One of the better ones of the series and a recommended read.