The Witch-king of Angmar, leader of the Nazgûl, used a magical dagger called a Morgul-blade to wound Frodo Baggins at Weathertop. The dark magic of the knife gravely affects Frodo's well-being, threatening to turn him into a wraith, especially because its detachable point migrated in Frodo's body for more than two weeks before it could be extracted, thus causing great damage. Recurring ill effects from the wound contribute to Frodo's eventual departure to Valinor. According to the J.R.R. Tolkien Encyclopedia, the weapon may owe something to the tradition of the elf-shot found in Old English medical texts and charms, where it denotes illnesses of presumed supernatural origin.