The 118 race to save the lives of workers trapped in a five-alarm factory fire. Meanwhile, Maddie reveals a painful family secret that causes Buck to confront his childhood and answer why he is the daredevil he is today.

The members of the 118 make calls to save a bridezilla at a disastrous wedding and to a mother trapped on her balcony. Meanwhile, Hen plays medical detective when her mother, Toni, falls ill. Also, Eddie and Christopher receive a visit from Carla, Athena uncovers a secret Bobby has been hiding that puts their marriage on the rocks and Maddie struggles with adjusting to motherhood.

In the aftermath of the shooting, Athena and the 118 are on high alert when a sniper is targeting members of the LAFD. Meanwhile, Maddie makes a life decision. Season finale

The 118 race to the rescues with emergencies at a spin class; in a hair salon and to a husband and wife in a compromising position; Buck discovers new cognitive abilities post lightning strike; Hen and Karen are concerned when they find out Denny has been seeing his biological father behind their backs; Maddie and Chimney enlist Athena and Bobby's help with a suspicious neighbor.