1 - Weldo Rubin Weldo knows where the magical city of Tulla is. If you're persuasive, then Weldo will mark the location of Tulla on your world map, and he'll even become available to join your group. If you're not persuasive, then you'll have a couple other options: you can either pay him or coerce him into giving you the location, or you can go on a quest for him.
If you choose the quest method, then Weldo will mark the Mysterious Ruins of the Wastes on your world map, and he'll ask you to bring him back a sprocket from the place. When you give him the sprocket you'll also receive 10,900 experience.
Weldo might also join you, but he's only level 25, so by the time you finally meet him he's probably too weak to pick up.