The Girl on the Train, written by Paula Hawkins, is a gripping urban mystery fiction book that explores themes of obsession, memory, and deception. The story revolves around Rachel Watson, a troubled woman who becomes entangled in a missing person investigation. As Rachel tries to piece together the events surrounding the disappearance, she becomes increasingly unreliable due to her alcohol addiction and fractured memories. Set in the suburbs of London, this book keeps readers guessing as it delves into the dark secrets and hidden motives of its characters.