After being taken on an arduous journey from Rome, a young slave called Marcus finds himself in the furthest reaches of the Empire, Britannia. Saved from working in an iron-ore mine by his unusual ability to read and write, he gains the trust and protection of one who has the power to help his situation. As he rises from a slave in the mine, to messenger, to manager of a mine and beyond, Marcus's quick thinking and reliability may gain him powerful friends, but they also bring enemies who are jealous of his newly found status. When his mentor takes a trip back to Rome, Marcus finds himself a prisoner on trumped up charges. His mentor returns, but this is a time of change, and, with the power of Rome ebbing, life is precarious for everyone, including Marcus and his new family.