This drama is adapted from the story of King Arthur and the magician Merlin, and is jointly produced by BBC Wales and Shine Films. King Uther's adopted daughter Morgana gradually discovered the powerful power she possessed. In order to escape Uther's atrocities of slaughtering magicians, she privately sought help from the ancient religion. Due to the appearance of her half-sister Morgause, the two joined hands to fight against the Kingdom of Camelot. Merlin (Colin Morgan) discovered Morgana's changes and tried to stop her actions. In order to save the kingdom, Merlin had to poison Morgana to death. At the critical moment, Morgause took the dying Morgana away. The dragon that helped Merlin many times couldn't wait to ask Merlin to let it regain its freedom. After all, Merlin cut off the chain that locked the dragon. The dragon finally counterattacked the Kingdom of Camelot, and finally Merlin conquered the dragon and became the dragon slayer.