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 mid-summer'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.