The Defiler is a quest given to the player as soon as he or she enters the Festering Nest. This quest involves finding The Defiler on the fourth floor of the Festering Nest and killing her. The monster will then drop the Cathedral Map, which is needed in the Grave Matters quest and to gain access to the Demon Crypts. "We have long lain dormant, and the time to awaken has come. After our long sleep, we are filled with great hunger. Soon, now, we shall feed..."