Merlin's epic quest continues as he journeys to Constantinople in search of his father. Myrddion Emrys of Segontium is the product of a brutal rape, but when King Vortigern hints at his father's identity, Myrddion embarks on a journey across France and Italy to Constantinople. It is a voyage that is to turn the young healer into a man of great renown.

Serving under General Flavius Aetius at the Battle of the Catalaunian Plains, Myrddion saves the lives of thousands of warriors and, on his arrival in Rome, he heals many more, including Cleoxenes, Envoy to Emperor Theodosius of the East, on his way to a delegation with Attila the Hun. But a deadlier conflict between Emperor Valentinian of the West and Senator Petronius Maximus is still to come and Myrddion must use all his strength to carry out his work in a world that is evil.