As Buck's life hangs in the balance, he dreams of a world where he never became a firefighter, for better and worse.

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.