The Gates of Avalon (S01E07)

Morgana experiences a chilling nightmare where she witnesses Arthur's demise at the hands of a mysterious yet enchanting girl. Meanwhile, while hunting in the woods, Merlin and Arthur come to the rescue of this girl, Sophia, and her father, Aulfric, who are under attack by bandits. They take them back to Camelot for safety. Morgana soon realizes that Sophia is the one from her dream and attempts to caution Arthur, who is instantly captivated by her. As Morgana's ability to foresee the future reveals itself, the sinister plot of a father and daughter to destroy Camelot by sacrificing Arthur for eternal life begins to unravel.