New TV: Netflix’s Firefly Lane Will Make You Miss Your BFF (Even More) Based on the bestselling novel, the new series follows wallflower Kate Mularkey and firecracker Tully Hart through 30 years of love, loss, sex, marriage, divorce and kids. Here’s how the duo echo some classic TV BFFs. Deidre Olsen Updated February 2, 2021 Based on Kristin Hannah’s bestselling novel, Firefly Lane follows the platonic love story of wallflower Kate Mularkey (Sarah Chalke) and firecracker Tully Hart (Katherine Heigl). The series sees them through 30 years of love, loss, sex, marriage, divorce and kids. Here’s how Kate and Tully echo some classic TV BFFs.