In the opera, Merlin's power in the supernatural comes from a magic harp, with which Merlin controls a demon who reluctantly does Merlin's bidding. While the demon bemoans his fate as Merlin's slave, the fairy Morgana offers to the demon this advice: "Only through the love of a woman can Merlin's powers be extinguished." After using his magic to win a victory over the Saxons for Arthur, Merlin identifies to Arthur a traitor, Bedwyr. File:Goldmark - Merlin Overture