It was good until Ep 12.
Every thriller drama has this one stupid character who opens the door when you are not supposed to if you have common sense.
when you hear a door bell and you see no one through door hole, no one responds to your question, and you see no one through the video security system that is inside your house and yet the female lead have the itch to see who is outside while she is actively being stalked.
What a disappointing Twist the writers seek here.