5 main ways the Netflix show deviates from the novel
The 2008 novel Avenue of fireflies was a huge bestseller for Kristin Hannah. It wasn’t until 13 years later that the book was finally made into a series for Netflix.
In 2021, we finally saw Kate Mularkey and Tully Hart on screen, played by Sarah Chalke and Katherine Heigl. The story revolves around these two women and their lifelong friendship. Season 1 deviated slightly from the novel, but Season 2 had even more changes.

Kate and Tully’s friendship spans three decades. They meet as young teenagers in the 70s when Tully and her mother Cloud (Beau Garrett), move away Avenue of firefliesand we follow them into adulthood in the early 2000s.
The road they travel is complicated and sometimes messy. These complications became somewhat different when the book was made into a series.
[Spoiler Alert: This article contains spoilers for Firefly Lane.]
The “Firefly Lane” timeline plays differently
The timeline in the book takes a linear approach. The story is told chronologically, starting when the girls are teenagers in the 1970s, and read until the women are in their 40s in the early 2000s.
On the other hand, the series jumps around the decades. The timeline goes back and forth and we see the girls in different stages of life throughout the series. We also witness the pop culture, hair and fashion of the decades.
Where were Kate and Johnny’s twins?
In Hannah’s novel, Kate and her husband, Johnny Ryan (Ben Lawson), have a daughter, Marah (Yael Yurman). But they also have twins, Lucas and William. Not only did the series leave out the twins, but it also added a struggle with fertility.
During a 1993 visit to Tully in New York, Kate shares her sadness with her best friend. Tully helps about her by telling her that having a child doesn’t make her any less of a woman and that she’s a great mom to her daughter. Marah is always an only child in the series.
Kate and Johnny’s divorce
A big change in the series is that Kate and Johnny get divorced, whereas in the book they don’t. It’s not even clear what caused the breakup. Johnny mentions that his wife has been having an emotional affair, but not much is shown about it.
The novel portrays Kate as a stay-at-home mom to her three children, but we see her return to work in the Netflix adaptation.
The relationship between Tully and Cloud
The early years of Tully’s relationship with her mother are similar in the book and series. Cloud is an irresponsible mother struggling with addiction that really ruins her daughter.
Cloud, in the novel, never really redeems himself. Tully tries over and over again to track her down and get her to rehab, but all Cloud wants is her money and she even steals her daughter.
By Netflix Avenue of fireflies it shows Cloud getting sober and forming a relationship with Tully. He’s with his daughter as she recovers from a miscarriage and even spends Christmas with Kate’s family. Cloud TV Series is redeemable.
What caused Tully and Kate to break up?
The cause of the rift totally depends on whether you are reading the book or watching the series. It’s probably the biggest difference between the two. The great battle in the novel is due to Tully’s show, Girl’s time. When Kate and Marah appear on the show in hopes of repairing their relationship, Tully turns things around and changes the episode to focus on overprotective moms.
He practically calls Kate a bad mother on national television. As a result, her best friend stops talking to her. The story is completely different in the series. In it, Tully gets into a car accident with Marah in her passenger seat after he saves her from a party she wasn’t supposed to go to.
Unfortunately, she got into the car after having a couple of drinks. Kate wouldn’t forgive her friend. Part 2 of Avenue of fireflies season 2 will premiere on Netflix on June 8, 2023. It remains to be seen whether the ending of the TV version will be the same as Hannah’s novel.