Triel was a city guard but she went insane very suddenly and killed several other guards. She ran off and was assumed dead from serious injuries. She has curly red hair, has a good number of tattoos and seems to have become a cleric of Hextor. She recently stole the water wands from Sarcem at the Lucky Monkey and may be working with the Last Laugh. She had a lair accessed via a lava tube outside of town. The lair was cleared out by Tarik's Company and Triel was killed in the process.
New information suggests that Triel may have been working with the Alleybashers as well.