In a high, drafty tower in Scotland, four brothers huddle for warmth. The eldest, Gawaine, tells the story of their grandmother, Igraine, the countess of Cornwall, who spurned the sexual advances of Uther Pendragon. When Igraine and her husband fled Pendragon’s castle, the king laid siege to the Cornwall castle. With the aid of Merlyn, Pendragon gained access to Castle Cornwall, killed the earl, and forced Igraine to marry him.

In the chamber below, the children’s mother, Queen Morgause (sister of Morgan le Fay), experiments unsuccessfully with an invisibility spell. The children, meanwhile, swear to forever oppose King Arthur as Pendragon’s heir.

From the battlements atop Arthur’s castle at Camelot, he and Merlyn look down upon the field of battle (the Gaelic War). The sword Excalibur has given Arthur the victory, but Merlyn warns that the Gaelic armies will return. He chides Arthur for his hubris and his casual disregard of the many lives lost in the battle. He urges Arthur to think not of the glory of battle but of the welfare of England and its people. He will not be Arthur’s tutor forever, and the young king must learn to think for himself.