Aoife and her brother Madoc are Roman slaves with a single dream: to get back to Britannia. So, when their master is murdered, they seize the chance to escape. But it isn't long before they are picked up by the slave catcher and dragged before the Emperor himself. Discovering that Aoife and Madoc are the children of the counsellor to Caratacus, the self-appointed king of Britannia, the Emperor orders them aboard his fleet. He is about to sail to Britannia to put down Caratacus's anti-Roman rebellion, and he realises what valuable hostages the children will be. But Aoife has a secret: she is a healer, with a special bond with animals. Onboard ship are the elephants that the Emperor will use when he rides in victory against Caratacus. Can Aoife forge a bond with the magnificent creatures and then, somehow, use them against the might of the Imperial army?