During the December festival of Saturnalia, Flavia Albia is twiddling her thumbs with no clients. But in this 9th adventure (after In the Grove of the Caesars), her husband Tiberius and the Fourth Cohort are battling organized crime interests that are going to war over the festival, resulting in accidental poisonings, the bloody murders of rival vendors, and finally a gruesome warning to Tiberius to back off. Albia has had just about enough and combines forces with Tiberius to uncover the hidden criminal gangs trying to worm their way into the establishment at a banquet for the emperor Domitian.