Merlyn Britannicus, Commander of Camulod, must educate his young charge, Arthur Pendragon, future King of Britain.
Threats against young Arthur’s life have forced Merlyn and the boy to leave Camulod, settling in an abandoned Roman fort, where they are safe from political intrigue. Enlisting help from a close-knit group of friends, Merlyn teaches the young King about warfare, justice, honour and the responsibilities of leadership in preparation to wield the sword Excalibur.
When the tenuous peace of Camulod is threatened by unrest in neighbouring regions, Merlyn faces a dilemma. How can he prepare the young Arthur to be a ruler of men when he continues to train him in isolation? Merlyn knows that he must risk the dream of his grandfather Caius Britannicus if he is ever to fulfill it.