Sonja forces Seth to get clean in order for him to pay her back for the damage he heist cost her. Even though she straps him to a chair, Sonja takes decent care of Seth, and even forgives him for pulling a gun on her.
We've heard a lot about Uncle Eddie on From Dusk Till Dawn, but now we are finally getting a chance to meet him in From Dusk Till Dawn Season 2 Episode 3.