Just finished this last night and really did find it to be a page turner. No really likeable characters, except maybe Scott and Cathy, although her enabling of Rachel was really at epic proportions.  The book is about Rachel, who rides the trains, not to get anywhere in particular but more to maintain a sense of normality and to avoid questions from Cathy.  As you find out within just a few pages of beginning the book, Rachel is an alcoholic and not just an alcoholic but a blackout drinker.  She is obsessed with her ex-husband and with a young couple (Megan and Scott) that are his close neighbors.  Rachel is engaged in a horrific downward spiral, that gets only more complicated when Megan is murdered and Rachel wakes up with injuries and blood on her and no memory of what occured.  The story takes you on this frustrating spiraling search with Rachel as she tries to remember, sorting through false memories and lies.

I had guessed the ending somewhat before  (it seemed obvious to me) but I don’t want to give any spoilers.  Just to say this is really  one of those stories that shows that you never really know someone else.  As an aside, there is an old movie that this reminded me of somewhat The Morning After, fans of the book might like the movie.