Cannot Locate Quest: Wrothgar - Tinker Trouble

Ignotus

I use the addon "Destinations" which puts quest markers on the map, among other things, so I won't miss a quest. There is a map marker around 22x75 (according to addon "Map Coordinates") for a quest called "Tinker Trouble". I can only find vague information about this quest using Google. I've also found mention of it in patch notes through Google searches, so I have to assume the quest existed at some point. I viewed some of the UESP addon's log data at their site which also seems to confirm the existence of the quest and the coordinates. Ingame, there is a small NPC camp with some dwemmer items at those coordinates, which again seems to point to the existence of the quest since it supposedly involves the Vanos siblings, who seem to be interested in dwemmer tech. The only NPCs that I found there are an NPC that you can steal from, and an orc that you trade Nord wine to for some Orc wine for a different quest (Cultural Affections). There is no quest pin on my compass in this area, and I cannot locate either of the Vanos siblings. I can only assume that there is some prerequisite to the quest, but Google isn't helpful. I have finished the King Kurog quest line and I remember seeing the Vanos' in the castle afterward I believe.

Ignotus

It appears that the quest An Unexpected Fall is the prerequisite for Tinker Trouble, which is why I could not find the quest. Thanks to the author of the Destinations addon for pointing this out.