A scandal is threatening to engulf the popular spa town of Aquae Sulis (modern-day Bath). The wife of Ruso's best friend, Valens, has been found dead in the sacred hot spring, stabbed through the heart. Fearing the wrath of the goddess and the ruin of the tourist trade, the temple officials are keen to cover up what's happened. But the dead woman's father is demanding justice, and he's accusing Valens of murder. If Valens turns up to face trial, he will risk execution. If he doesn't, he'll lose his children. Ruso and Tilla do their best to help, but it's difficult to get anyone --- even Valens himself --- to reveal what really happened. Could Ruso's friend really be guilty as charged?

Ruso and Tilla's excitement at arriving in Rome with their new baby daughter is soon dulled by their discovery that the grand facades of polished marble mask an underworld of corrupt landlords and vermin-infested tenements. Ruso thinks he has been offered a reputable medical practice only to find that his predecessor has fled, leaving a dead man in a barrel on the doorstep and the warning, “Be careful who you trust.” Distracted by the body and his efforts to help a friend win the hand of a rich young heiress, Ruso makes a grave mistake, causing him to question both his competence and his integrity.