This drama is adapted from the story of King Arthur and the magician Merlin, and is jointly produced by BBC Wales and Shine Films. After Morganna's plan to seize power failed, she led the dying Morgause to flee Camelot. On the night of Samhain, Morganna sacrificed her blood at Morgause's request in order to break the barrier between the world and the spirit world and create a new world; the gatekeeper of the spirit world, the Winter Spirit, told her that a man named Emerys would become her doom. From then on, Morganna hid in a dark room deep in the forest, and used Arthur's uncle Aguwin to plan to attack Camelot and find the whereabouts of Emerys. Arthur and his knights, as well as the manservant Merlin (Colin Morgan) continued on the road to find the island of God's blessing. On the way, Merlin was haunted by the vengeful spirit to protect Arthur. Merlin, who woke up, summoned the dragon and found a way to repair the enchantment. Morgana's betrayal made Uther extremely depressed and he ignored state affairs. Eventually, he died under Morgana's scheme and Arthur inherited the throne...