During the reign of the young Louis the XVI, Nicolas Le Floch must struggle through terrible events, political and personal alike. Back from a mission in Vienna, he finds Paris in an uproar: the bakers' blood. With the support of the king and the help of his faithful friends, he investigates the suspicious murder of a baker that soon leads him to suspect a plot.

Nicolas Le Floch is going through a rough period: Louis XV is dead and Sartine has resigned from his post as Lieutenant General of Police to become Secretary of the Navy. Nicolas now works under the orders of a certain Le Noir and must investigate a murder committed at Monsieur de Saint Florentin's Mansion, minister to the new king.