The story of Merlin and King Arthur continues in the second of Mary Stewart's beloved Arthurian Saga.... the story of Excalibur, the sword of kings.

Born on Christmas Eve, Arthur Pendragon is the illegitimate son of the married duchess Ygraine and Uther Pendragon, brother of a great king: a union Merlin arranged. But Arthur's birth is not welcomed by everyone: his father demands he be hidden until a legitimate son can be born, and Merlin is forced to give the babe to his own childhood nurse for safekeeping and go into hiding.

In a dream, Merlin learns of a sword of unparalleled beauty and extraordinary craftsmanship, hidden in a long-deserted Roman temple. Merlin retrieves the sword and hides it in a cave on an island in the centre of a lake, where it remains for years.

But what is hidden must be revealed. For it is foretold that the irrepressible young man named Arthur will find a sword and claim his birthright: as heir to Uther Pendragon and king of the Britons.