The Simpleton's Mother - NWN Side Quest (Chapter 2)
The Simpleton's Mother is a side quest that begins by speaking with Revat inside of the Archaeologist Barracks on the East Road map. To gain access to these barracks you'll want to accept East Road: What Lurks Below from Jax who is standing outside of them. You will find Revat roaming around one of the rooms on the first floor inside of the barracks.
For this quest you'll be tasked with finding Janis, Revat's Mother, who has been taken hostage by the trolls. You'll find Janis in the Troll Caves - Storage Area map which can be easily accessed by entering the cave in the northeast portion of the East Road map. Alternatively you can reach the Troll Caves - Storage Area by traveling through the Troll Caves Level 1 map.
When you first find Janis she will be imprisoned by her own spell (pictured below) and you'll have to give her the ring that Revat gave you to free herself. Once she is free tell her to get out of here and then you're pretty much done with the quest.
All that's left is to return to Revat in the Archaeologist Camp and speak with him for your reward.