It was created by Shilarn Silmaeril as a gift to her daughter Lhestyn. Lhestyn used the mask to infiltrate the Shadow Thieves with the goal of investigating the guild's activities. After successfully exposing the guild, the mask then became a symbol in Waterdeep. Waterdhavians look upon the mask as a symbol of justice. When Zelphar Arunsun, Lhestyn's husband, died in 1311 DR, the mask vanished. Many suspected he was murdered by the Shadow Thieves; however, the guild continued to search for the missing mask.