In order to break free from the clutches of evil warriors and witch Mogana, Merlin brought the young King Arthur to modern America. Ten years later, when Merlin came back to find him, he found a fashionable 15-year-old Arthur who didn't believe in Merlin and didn't want to go back to the past. Merlin must convince Arthur of her true identity before Mogana can retrieve the Divine Sword and allow the dark Ones to take over the world.