Well, it's simple, i cant find the damn child that one of those gnomes has lost. Is it in the underdark, or in one of the semi-quests (mind flayers, drow or beholders crypts?)
thanks for the help

It's in the Underdark cave itself. There's a big device that has a few windows on it near where you have to battle several Drow. It's kinda dome shaped. Click on a window and someone comes out. Most of the time it's someone bad that you have to fight, but there's one that has the kid in it.

I've never found the point of that dome. Only that souls or something has been trapped in side it. Anyone know?

It's a sort of prison... IIRC either one of the gnomes or Drow can tell you something about it.