Warning: Spoilers for the ending of Firefly Lane. So you've binged the whole of Netflix's Firefly Lane, and you're equal parts heartbroken (what did Tully do?) and irate (how could they end the series like that?). Now, you're wondering how Kristin Hannah's book Firefly Lane, which provides the source material for the series, ends—and whether the book ending will provide clues for season two of the series, should it happen. At the very least, you're hoping to get answers about how the friendship between Tully and Kate, played by Sarah Chalke and Katherine Heigl, imploded.
Well, my friend, look no further—because the book version of Firefly Lane does answer some of your questions (emphasis on some). Fair warning: It also has an unbearably sad ending—yes, even sadder than that funeral scene between Tully and Kate—which Netflix left out of season one. Prepare to bawl when you find out what happened to your favorite Firefly Lane girls.
Tully betrayed Kate on live television.
Season one of the series ends with Kate telling Tully that she can never forgive her for what she did. We never find out what Tully did, exactly—but the book might provide an answer.
In Hannah's book, Tully brings Kate and Marah onto The Girlfriend Hour until the pretense of fixing their relationship. To Kate's horror, however, the segment is actually about overprotective mothers and the damage they do to their kids. In other words, Tully is decrying Kate's parenting—on national TV, no less.
Furious, Kate storms off the show. Johnny, who also serves as Tully's producer and Kate's husband in the book, just as in the series, quits in solidarity. Smarting from the humiliation, Kate believes that her friendship with Tully is over for good.
So, is that what caused the rift between them in the show? Well, it's very possible that that scene from the book will be written into season two. Showrunner Maggie Friedman noted to Entertainment Weekly: "One of the things I think that's been fun is that we have kept some big moments from the book and been very true to those, and then there are other things that we've done that are different."
It's worth noting that Marah and Kate seem to be on good terms at Bud's funeral (RIP, Bud!)—so if that is what happened between Kate and Tully, it didn't seem to hurt Kate's relationship with her daughter. Another note: Tully does quit The Girlfriend Hour at the end of season one, before any betrayal takes place, though of course she and Kate plan to start their own show in season two (and maybe it's there that the segment takes place?).
And it's possible we may not even find out in season two. Heigl told Collider: "I always assumed that [the reason for Kate and Tully's rift] would be revealed in Season 2. But maybe not. Maybe it is something that you could really draw out."
Tully and Kate reconcile...before Kate dies.
I know, I know. In the series, we're led to believe that Tully was sick, and perhaps even dead, thanks to the ominous funeral flash-forwards. But it turns out Tully was pregnant, and Bud, Kate's dad, was the person who died.
In Hannah's book, it's Kate who begins exhibiting frightening symptoms, not Tully. Kate is diagnosed with terminal breast cancer, and Tully rushes back home from a reporting trip to make amends with her. They reconcile, and Kate asks Tully to please take care of Johnny—who she remains married to; they never get divorced in the book—and Marah when she's gone. Then, Kate passes away. I know: It's even bleaker than the somewhat bleak end of the series. (Said Roan Curtis, who plays young Kate, to Oprah Mag: "I don't think I've ever cried so hard reading a book... It feels so unfair, the way that Kate's story ends.")
Can't get enough? There is a sequel to Hannah's Firefly Lane book. In that book, Tully and Kate "reunite" when Tully is in a coma after a serious car accident.