Girl on a Train

Okay, I'm going to read, Girl on the Train, by Paula Hawkins. It's been on the New York Best Sellers list for many weeks. I've read the reviews and it sounds like an exciting book.
Paula says that she enjoys the "odd sense of connection you get as a commuter' with the people and place you pass each day. And then idly wondering what it would be like if you saw something shocking or sinister.
She says, "It's the stories that lead you to the violence that are interesting."