Actress Sarah Chalke, who is best known for her roles on Scrubs and Roseanne, has been confirmed as one of the other Firefly Lane stars— the shy awkward Kate. The television adaptation also previously announced co-star Katherine Heighl will be the other lead for the Netflix 10-episode produced drama.

Currently finishing up her two-season arc on USA Network’s Suits, Heigl is set to play Tully Hart, with her official character description reading, “dogged by inner loneliness, even as she goes on to fabulous fame and fortune as a journalist and talk show host. Her saving grace is her best friend and soulmate, Kate (not yet cast), with whom she shares an unshakable bond, over the course of four tumultuous decades.”

Kristin Hannah’s best-selling book focused on two inseparable best friends who grow with each other through several ups and downs. The original novel’s synopsis covers:

The turbulent summer of 1974, as Kate Mularkey has accepted her place at the bottom of the eighth-grade social food chain. Then, to her amazement, the “coolest girl in the world” moves in across the street and wants to be her friend. Tully Hart seems to have it all—beauty, brains, ambition. On the surface they are as opposite as two people can be: Kate, doomed to be forever uncool, with a loving family who mortifies her at every turn. Meanwhile Tully, is steeped in glamour and mystery, and carries a secret that is destroying her. Both make a pact to be best friends forever; by summer’s end they’ve become TullyandKate.

From the outset, Tully struggles to prove her worth to others in her life as she deals with deep seated issues  of abandonment from her mother at an early age— she longs to be loved unconditionally by those around her. Throughout the 80’s, Tully uses the men around to help fill the deepening void within her soul. But as she outgrows her old habits by the 90’s, the rise of television news proves to be of more interest. She begins a whirl wind career in TV after suddenly leaving to New York in the hopes of finding herself and what she really wants.

In contrast from an early age, Kate struggles to find much meaning in her young adult life. Throughout college, she puts on the facade that she is ambitious and driven by success, but deep down she longs to find the Mr. Right and settle down with children in a quiet home. However, although she is equally single-minded in pursuing her goals just as much as Kate, she struggles with the challenges motherhood brings on. Soon, her former single life begins to haunt her and she begins to struggle with her pangs of jealousy for Tully’s lifestyle.

Witches of East End‘s Maggie Friedman will serve as the series’ writer, showrunner and executive producer— Stephanie Germain, Lee Rose and Heigl will all also jointly execytive produce the adaptation. Peter O’Fallon of UnREAL fame, will direct the premiere episode.