Long story short, I beat the waterworks, tried to get the next quest from Herman, he just turns and stares at me, yes he does have the '!' above his head, I can haz help plz?
"After completing Waterworks, Herman appears to have a quest, but in actuality does not. He does not have a follow up quest, so please ignore his gold question mark."
If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.