May, AD 41. The emperor Claudius has acceded to the throne, and the citizens of Rome look forward to an era of peace and stability. Not so Marcus Corvinus however, who finds himself embroiled in not one but two investigations. A friend of his wife has asked him to look into the murder of her brother, found stabbed to death at the Shrine of Melobosis. A wily businessman and notorious womaniser, no one seems to have a good word to say about Gaius Tullius, not even his less-than-grieving widow. But who would have a good enough reason to want him dead?

At the same time, Corvinus's daughter comes across a dead body in the Pollio Gardens, and urges her father to investigate. At first Marcus refuses to get involved - but when his enquiries lead him to Ostia, Rome's busy trading port, he uncovers a disturbing connection between the two deaths.