"The Girl on the Train" is a psychological thriller novel by Paula Hawkins, first published in 2015. The story is narrated from the perspectives of three women: Rachel Watson, Anna Boyd, and Megan Hipwell, whose lives become entangled through a series of events surrounding a missing persons case.The novel explores themes such as addiction, memory, infidelity, and the complexity of human relationships. It delves into the unreliable nature of memory and perception, as Rachel's narrative is often unreliable due to her alcoholism. The suspenseful and twist-filled plot keeps readers guessing until the very end. "The Girl on the Train" received widespread acclaim for its gripping storyline and complex characters. It was a commercial success and was adapted into a film in 2016, starring Emily Blunt as Rachel.