Rachel rides the train back and forth to the city every day, and particularly enjoys watching out the window at the world that passes her by. She becomes interested in a couple on their deck, giving them names, "Jess" and "Justin" and making up stories to herself about their lives. But then she sees something that upsets her and she is determined to figure out exactly what is happening with this couple that she thought was perfect. The Girl on the Train by Paula Hawkins is a psychological thriller that has been hyped up quite a lot lately. It lived up to the hype, for the most part, but it's still one of those novels that is hard to review since I don't want to give away too much. All I knew going into this book is what I wrote above, and that made the story much more exciting and engaging. Rachel is a complex character, and so is "Jess," who is really Megan. We get to hear from both of these women, as well as a third, throughout the novel.