Content Warning: This section of the guide refers to alcohol misuse and infertility.

Thirty-eight-year-old Marnie Walsh realizes that she’s lonely. Since divorcing in her late twenties, she has had no significant romantic relationships. Meanwhile, her friends married, had children, and drifted away. Marnie is accustomed to being alone in her London apartment, often talking to inanimate objects or herself. However, scrolling through social media, she realizes that she hasn’t taken a photo of another person for six years and craves companionship.

Forty-two-year-old Geography teacher Michael Bradshaw is on a field trip with his students in Wales. Passionate about his subject, he tries to convey the scale of geological changes over millennia to his unenthusiastic teenage pupils. Michael was unable to have children. He recalls how some pupils laughed when they saw him crying in the car after his wife left.

Marnie is a self-employed copyeditor who works from home and rarely takes a holiday. Sometimes, her professional skills spill into her personal life. Her former husband became angry when she corrected his grammar.