A cursed weapon carried by the Nazgul, designed to break off a fragment in the victim's body that works its way towards the heart. If the shard reaches the heart, the victim becomes a wraith under the dominion of Sauron. Frodo is stabbed by a Morgul blade on Weathertop, and only the skill of Elrond in Rivendell saves him from this fate, though the wound troubles him for the rest of his life.