The following version of this book was used to create the guide: Hannah, Kristin. Firefly Lane. St. Martin’s Paperbacks, 2021.

Tully Hart is 10 years old when the novel begins. She lives with her grandparents. One day, her mother, Cloud, comes to claim her. Cloud is a drug addict. She takes Tully to a protest and loses her in the crowd. Four years later, Cloud comes back again. She takes Tully to live in a small town called Snohomish. Their new house is on Firefly Lane, where the Mularkey family lives. Kate Mularkey is Tully’s exact age. Tully is popular and Kate is a nerd. The two become best friends after Tully tells her about how she was raped at a party.

From that moment on, the girls are inseparable. Cloud gets arrested and Tully goes back to live with her grandmother. The girls stay in touch and remain best friends. When Tully’s grandma dies, she moves in with the Mularkeys. The girls spend the rest of high school together and then go to the University of Washington. They join the same sorority and live together throughout college.

In college, Kate focuses on finding true love while Tully focuses on furthering her career in journalism. She becomes involved with her professor, Chad Wiley. Chad loves her genuinely and the two stay together after Tully graduates. Tully gets Kate a job at her broadcasting network, thinking that they share a dream of becoming reporters. Kate falls in love with their boss, Johnny, who is infatuated with Tully.

One day, Tully gets shot by a robber at a supermarket. She continues reporting, thanks to her earpiece and microphone. This gains her overnight success and a job at a bigger broadcasting company. Chad proposes to her while she is in the hospital. Tully says nothing and they break up soon after. Tully feels incapable of loving.

One night, Tully and Johnny have sex. Kate is heartbroken. Tully becomes bored of Johnny and stops returning his calls. Kate tells Johnny how she feels about him and they have sex. Then they become an official couple. Kate tells Johnny she is pregnant, and he proposes. Kate has a miscarriage. They buy a house and Kate gives birth again to a girl named Marah. Tully becomes a famous reporter.

Johnny leaves for Baghdad to report on the war going on there. He gets injured in a bombing and is sent to a hospital in Germany. Kate and Tully go there. Tully does a report on him for her network, infuriating Kate. The two make up once Johnny recovers.

Kate starts taking creative writing classes in the hopes of pursuing a career in it. Then, she finds out she is pregnant with twins. She abandons the idea to be a stay-at-home mom. A few years pass. Marah is 10 and Lucas and William are 2. Kate feels burnt out from taking care of them and being so involved at their school. As Marah enters puberty, their relationship grows strained.

Meanwhile, Tully goes on being famous, despite feeling empty inside. She searches for Cloud one day and finds her. They go to a hotel but Cloud leaves without saying goodbye. Tully gets her own TV show which she decides to call The Girlfriend Hour. Johnny is her producer. Tully grows close with her goddaughter, Marah, who prefers her to her own mother, Kate.

Tully has Kate and Marah come on The Girlfriend Hour to try and solve their problems. She introduces the segment as one about overprotective mothers and their daughters who hate them. Kate is furious and feels betrayed. The two go without speaking for a year.

Kate finds out she has breast cancer. On the day of her mastectomy, she calls Tully. Tully never calls back. Several months later, she is in the hospital again. None of her treatments worked and the cancer spread to her brain. She calls Tully again and this time Tully comes. Tully moves in with Kate and Johnny and they all spend the summer and part of the fall together. Tully gives Kate a journal in which she writes down the story of their friendship. Kate tells Tully she should help Marah pursue her dream of acting.

One fall day, Kate dies peacefully. At her funeral, Tully steps outside. The funeral director gives her a box that Kate prepared for her. Inside, is a letter telling Tully how much she loves her, a cigarette, and an iPod. Tully listens to the song Dancing Queen by ABBA, a song from their youth, and dances.