So.....(Spoilers)

Okay, so it seems that people in the first story are connected to the third story. The sister and the brother's old wife are actually the "mother" and "grandmother." And the girl in the third story is the little girl in the first one.

But what I don't understand is why the sister and the old wife became crazy? And why there seems to be something wrong with the girl.

I don't know. This movie was just plein weird. Seems like something my local art channel would show.