The Sorcerer : metamorphosis

Threats against the life of young Arthur Pendragon have forced Caius Merlyn Brittanicus to take him away from Camulod. They make their home in a long-abandoned Roman fort called Mediobogdum. As Arthur grows, Merlyn can see the day when he will wield the sword Excalibur and become the legendary King Arthur of Britain. With Arthur now in his teens, Merlyn realizes that time will be soon and they must return to Camulod so Arthur can complete his training. There is great unrest in the land and Merlyn knows that soon Camulod must be defended against its enemies.