If you see the whole show, you will like the ending. BUT..during the show, we see that the woman gave her former lover a set of keys to her apartment when they were happy together.
Of course, things fall apart, she breaks off the affair, and then she finds that he is stalking her and ruining her life.
Does she change the locks to her apartment? Nope. You can guess what happens.
Lame on the writer's part.