Year of the Osprey is the fourth volume in the continuing saga of Justin and Sophie Cataphlates, a very unlikely husband-and-wife crime-fighting team. Set in the year 1000, here we learn how the newlywed couple began their careers. When the novel begins, Justin is a very junior-level bureaucrat while his wife is a junior lady-in-waiting to Princess Zoe, the oldest daughter of Emperor Constantine, one of two reigning emperors of the Roman Empire.

While carrying out their duties, the couple is called upon to solve the murder of an empire official and the suspicious reasons behind it, the theft of Princess Zoe's jewels, the disappearance of a precious icon, and multiple murders of disabled veterans. They accomplish all of this with their usual aplomb, not knowing that their real enemy is the Fatimid caliph of Egypt, who anticipates the coming struggle!