Britannia, 45 AD: Vespasian's brother, Sabinus, is captured by druids. The druids want to offer a potent sacrifice to their gods - not just one Roman Legate, but two. They know that Vespasian will come after his brother and they plan to sacrifice the siblings on Midsummer's Day. But to whom will they be making this sacrifice? What were the gods of this land before the Celts came? Only the druids still hold the secret and it is one of pure malevolence.

Vespasian must strive to save his brother whilst completing the conquest of the south-west of the haunted isle, before he is drawn inexorably back to Rome and the heart of Imperial politics. Claudius' three freedmen remain at the focus of power. As Messalina's time as Empress comes to a bloody end, the three freedmen each back a different mistress. But who will be victorious? And at what price for Vespasian?