This drama started off very well, but I dropped when it got to the backstory with the mistresses. I also just couldn't get past that creepy incestious relationship the doctor had with his stepmother.
Her performance in season 2 of penthouse kinda reminded me of a young Lee Yu Ri when she was Jang Bori is here. She went to sounded sweet to sounded totally insane.
BTW your comment has bit of a spoiler, so I think putting that in a spoiler would be a good idea