I could be way off, but when I read The Girl on the Train (no offense to the movie but, not the movie, the book specifically) I wondered if Rachel was an sx 9... I could just relate to her so much, I remember at one point in my 20's I was a lot like her, wanted to be with someone unavailable and had lost most everything else I wanted, and I would just ride the train aimlessly... I would just daydream about romantic stuff and wish things could be the way they used to be. I saw a 3 online (well I think he was a 3) who also enjoyed the book say he felt sympathy for her but that she was "sloppy" lol, I loved his comments.