It is spring in the year 118, and Hadrian has been emperor of Rome for less than a year. After his long and reluctant investigation of the murders of a handful of local prostitutes, Gaius Petreius Ruso needs to get out of town. With that in mind, he has volunteered for a posting with the army in the far reaches of Britannia -- a calmer place for a tired man. But the edge of the Roman Empire is a volatile place; the independent tribes of the North dwell near its borders. These hinterlands are the homelands of Ruso's slave, Tilla, who has scores of her own to settle there: Her tribespeople are formenting a rebellion against Roman control, and her former lover is implicated in the grisly murder of a soldier. Ruso is once again unwittingly pulled into the murder investigation, and he is honor-bound to try to prove the prime suspect innocent by finding another culprit.