This is a disturbing episode that makes you really uncomfortable listening to it.  The father is just an absolutely horrible, viscous brute. I don't know if there was an incestous relationship or not;but, there is a feeling you get that makes does you wonder. I was surprised that the sister that ran off didn't take her youger sister with her when she first ran away. She knew she would be leaving her with their father and he would probably subject the younger sister to even more abuse that the older sister couldn't protect her from. It brought back to me what my mother and I witnessed years ago at a Dept. store-we were looking over some clothes and a mother with a young daughter just absolutely went berserk and starting yelling abuse at the girl for no reason. The little girl wasn't running around or screaming or knocking things over like you see alot nowadays The store went silent and everybody froze. The woman keep berating the poor girl and dragged her by the arm out of the store.  I dread to think what happened to that little girl that day and at home with a mother like that.