S2, E1: On one of the hottest days of the year, the first responders are pressured as harrowing incidents keep happening, including a road rage accident involving a van full of tourists, an emergency at an auto-repair shop and a vet with a live grenade embedded in his leg. Meanwhile, Buck is visited by his sister. Also, Athena questions her relationship with Bobby. Then, at the fire station, new hire Eddie jeopardizes Buck's chances of being chosen for a fireman calendar.