When their tribe in Britain is conquered by the Romans, Bran and his young sister, Hilda, are taken to Rome and sold as slaves to a wealthy Roman household. Filled with anger, Bran grows to hate everyone except Hilda, even rejecting the kindness shown to him by an elderly slave named Anicetus. Meanwhile, Hilda hears stories of the Roman god, Saturn, and longs for the day when he will rule the world in a Golden Age where everyone, including slaves, will be happy and free. One day, Anicetus takes Hilda to hear a prisoner named Paul and she learns of another God, a God who made the heavens and the earth and who loves slaves. Soon Hilda and Bran must decide if they are willing to follow this new God and to live in obedience to His commands.