...And end up accidentally doing the other quest you were trying not to do. You say OK you can help this guy out real quick but you've got stuff to do after that.
The mapmaker explains they were trying to map odd corners of the land, but ended up in a corner that was a bit too odd. They say if the Dreamer is back they'd like to go back to the surface and see if there's a place to settle down. They can even show you a return node if you're not sure how to get back up.