Set at the time of the Roman invasion (AD40-3) the story is about the last British king. It opens in Rome with a mad parade of Caligula as a living god. To escape the insanity, Togidubnus, a son of King Verica who has been living in Rome as a hostage since the age of ten, accepts a mission to Greece in service of Vespasian. The Oracle at Delphi tells him to ‘go home and marry your mother to your father.’ He assumes this means legitimize a union founded on rape, but he does not want to go home to barbaric Britain. Togidubnus, who prefers his cradle name of Delfos, is a keen student of Seneca. But fate cannot be stalled: his father Verica, dispossessed by a rival chieftain, Caratacus, comes to Rome to appeal to Emperor Claudius for help. Claudius agrees and sends Verica and his son home in advance of the army to negotiate with the tribes, promising them peace and prosperity in return for submission to the Romans.
Once home in Britain, Delfos begins to find his own barbarian roots. His visionary powers bloom into full life and he sees and communes with the spirits of the land. The Roman plan for him to go on a straight road to the great midsummer assembly at Venonis is queered at every step and, having begun his journey north, Delfos is soon being led south. This takes him to Avebury and Bath and into the company of druids.
Britain is divided between those who welcome the Romans and what they offer in increased trade and prosperity, and those who will fight to the death to remain free. Delfos soon finds he is of both persuasions and relies partly on his stoicism, partly on the guidance of spirits, to grope his way forward through uncertain territory to the climax of the book at Venonis.
A sequel will take the story to AD46 and the genocide of the druids.