The story of King Arth-yr Ddantgwyn comes to an end in the 520AD, in the battle of Camlann. In the heat of battle, Arth-yr, with the legendary Excalibur, lands a fatal blow to his son Mordred, before receiving a deadly wound himself. Before succumbing to his wounds, he tasks his loyal knight Sir Bedivere with returning Excalibur, the source of Arth-yr's powers, to the Lady in the Lake.