Here is one big spoiler for you, and it's very, very sad.
Firefly Lane, a popular Netflix series based on the eponymous novel by Kristin Hannah, just officially reached its finale, as the second part of Season 2 hit the screens on April 27.
The novel and the show's story is centered around the life and friendship of Tully Hart (Katherine Heigl) and Kate Mularkey (Sarah Chalke). And just like the original novel, the series ends in a tragedy.
Netflix's drama series depicts Tully and Kate's enduring friendship through a long period of time — from the 1970s to mid-2000s. The characters have gone through many adventures and tribulations together. At times, events threatened to tear them apart, but the two always managed to reconcile in the end. There was only one thing that could sever their close bond.
In the second half of Season 2, Kate learns what the book readers already knew and what has been heavily foreshadowed by the trailer — she has a malignant form of breast cancer. The character does her best to fight the disease and then settle her affairs, as the chemo treatment proves futile. Kate even makes peace with her ex-husband Johnny and remarries him — that is the wedding that the half-season teases early on.
Tully abandons her trip to Antarctica and hurries back home as soon as she learns of her friend's situation. She tries to support Kate in her cancer battle and make the remainder of her life as joyful as it can be. Meanwhile, she also reignities her relationship with her ex, Danny, and it's implied (though not explicitly shown) that the two get married eventually.
Ultimately, Kate succumbs to cancer — the only solace is that she has Hollywood-style cancer that makes her slowly wither, so she can calmly prepare for her own funeral and finish the book on which she has been working.
As she finishes the book, Kate gives it to Tully — it's revealed to be a biographical book titled Firefly Lane. The friends spend one last day together, and Kate passes away peacefully in her sleep. Tully is crushed by her death but manages to muster the strength to go on with her life, thanks to her own fortitude and the final gift from Kate.
Johnny overcomes his grief and is shown attending the wedding of his daughter with Kate, Marah. Despite the tragedy, life goes on.