"The Girl on the Train" is based on the psychological thriller novel written by Paula Hawkins, published in 2015. The story revolves around Rachel Watson, an alcoholic woman who is devastated by her recent divorce from Tom. She takes the train every day, passing by her old house, where her husband now lives with his new wife, Anna, and their daughter. During her daily train journey, Rachel becomes obsessed with a seemingly perfect couple, Megan and Scott Hipwell, who live a few houses down from her old home. She creates an imaginary life for them and becomes emotionally attached to their relationship. One day, Rachel witnesses something shocking involving Megan and Scott, which leads her to become entangled in their lives. The play explores themes of deception, betrayal, and the consequences of our actions. It is a complex and gripping story with unreliable narrators and unexpected twists.