Rachel, in the first person, describes her train journeys for about a week. There are entries dated July 5, a Friday, and July 8-11, Monday through Thursday, in 2013. The dates are broken into morning and evening sections, for the rides to and from London.

As she travels into the city from suburbia in the mornings, she notices clothes by the tracks and watches a particular house, number 15. Rachel wonders about the clothes, specifically if they belonged to someone who was hit by a train. She also fantasizes about the residents of number 15, calling them Jason and Jess (their real names are later revealed as Scott and Megan). They live a few doors down from her old house, number 23, which Rachel shared with her ex-husband Tom. She compares them to her and Tom when they were married. Eventually, Rachel admits she never met the couple that lives in number 15 because they moved in after she left.

In the evenings, Rachel drinks heavily, bringing gin and tonic fizzes, as well as wine, onto the train to Ashbury. She recalls her and Tom’s vacations and weekend activities. Rachel has been staying with her friend Cathy since the break-up and feels uncomfortable with her living situation.