In the kingdom of Dyfed, Vortigern, Celtic High King of Cymru and the North, rules in relative peace. Yet his choice of wife - a Saxon queen - fuels tension between the Saxon and Celtic tribes. In the town of Segontium, a young boy is raised by his grandmother. The product of a brutal rape, he is spurned by his mother as a demon child. The boy is Myrddion - prince of the Deceangli and apprentice to a skilled healer.
Far away, Vortigern oversees the resurrection of ancient Dinas Emrys. According to prophecy, the king will perish if the fort does not rise again. But the foundations refuse to hold and Vortigern needs the blood of a demon seed - a human sacrifice - to make the towers stand firm. Myrddion's life is in danger. Yet the child has a prophecy of his own and a greater destiny to fulfil...
