This is the fourth book in the Hawk and Fisher series. This one begins to show more of Hawk and Fisher's pre-Haven history. The story opens with Hawk and Fisher trailing a spy. But the spy gets away and holes up in a tower belonging to the Quality (the Aristocracy). The two guard captains must go undercover and pose as distant relatives in order to locate the spy. Unfortunately posing as a member of the Quality is punishable by death and headquarters will not back them up if they are found out. While trying not to blow their cover, the two infiltrate the tower where a new lord is taking command. Unfortunately a dead body turns up and everyone learns that there is an undying Freak locked up somewhere in the tower. Tensions rise and Hawk and Fisher have three tasks; try not to be discovered, find the spy, and try to stop the Freak before it kills everyone.