In 1491 DR, Teresiel was chosen among many others to be part of a diplomatic delegation to Mirabar. However, at Beliard in the Dessarin Valley, they were ambushed by the Cult of the Black Earth. Teresiel was captured and transported beyond the River Dessarin. There, in the Sumber Hills, they were attacked by the Cult of the Howling Hatred, but Teresiel remained in Black Earth's custody.
Some time after being transported to the Fane, however, she was ceded to the Cult of the Eternal Flame, who put her in a jail in their section of the Fane until some adventurers infiltrated the temple and freed her.