What is with me and the "ladies in peril" books lately? I dunno, but I definitely recommend this one as well.
THE GIRL ON THE TRAIN by Paula Hawkins is a psychological mystery set just outside of London. Rachel, a recovering alcoholic and an unreliable narrator if there ever was one, rides the train to London every day. On the ride, she looks for a Victorian house that's not too far from the one she used to share with her ex-husband. Rachel loves the couple who lives there--she has never met them, but she has mentally dubbed them Jason and Jess and has filled in the imaginary details of their lives.
Then one day Rachel sees "Jess" kiss another man on her back porch. And a few days after that, missing posters start going up. And soon Rachel finds herself obsessed with figuring out what happened the night that Jess/Megan disappeared.
Rachel tells the bulk of the story, but there are also flashbacks from Megan's perspective--the woman who Rachel knows as Jess and who will go missing in roughly a year. Interspersed with these two narratives are chapters narrated by Anna, the woman who broke up Rachel's marriage and who now lives down the street from Megan and her suspected-of-murder husband.
I personally guessed the culprit fairly early on in the book, but there are enough twists and turns that I was never completely sure and definitely didn't know how everything had gone down. There were two or three big shockers that I didn't see coming at all. Definitely recommended for mystery lovers.