Bruno is an Italian ex monk who has been excommunicated for heretical writings and for leaving holy orders, he finds himself in Elizabethan London engaged as a spy/detective by Francis Walsingham. In Conspiracy, Bruno has moved to Paris only to find himself embroiled in murder, rivalries between the supporters of King Henri, his mother Queen Catherine, the Duke of Guise, the Catholic League and the Huguenots.
This is a complex political murder mystery with several layers of deception, it feels as if it gives a good sense of the struggles of the time. If you enjoy the historical detective/spy genre (e.g. CJ Samson or SG MacLean) you should give Parris a try.