After you go to your old place and evict the squatters in the main quest “An out-of-the-way place”, a person named Frugality will show up on your map. It is not possible to pass him without triggering a scene. Agree to help him get rid of the junkies at his workshop.

Go past Frugality down the tunnel and to your left. Stop in front of the door and listen to a conversation between Providence, Chance, and a junkie. Your goal here is to help Providence find a solution. 

Chance and the Junkie turns out to be her sons. Do not instigate a fight and offer to find the dealer. Once he is taken care of, you have to talk with Providence again to complete this side quest.