On one of the hottest days of the year, the first responders feel the pressure as harrowing incidents keep happening around the city, including a road rage accident involving a van full of tourists, an emergency at an auto-repair shop and a grenade. Meanwhile, Buck gets a surprise visit from his sister, and a handsome new hire Eddie jeopardizes Buck's chances of being chosen for a fireman calendar.

The 118 deals with a situation where a stunt driver is placed in a precarious position, two mail bombs are detonated and a teenaged social influencer loses their mind; Eddie's family decides to visit; Buck confronts a deadly series of events.

The 118 responds to a viral stunt gone haywire, a disaster at a couple’s fishing trip and an epic first date fail. Meanwhile, Athena investigates a woman who doesn’t remember being shot in the head and Eddie is forced to have a difficult conversation with Christopher.

Athena investigates a mysterious murder during a neighborhood block party and the 118 rush to save lives endangered by a bomb threat. Meanwhile, Chimney has a hard time keeping secrets when Maddie and Buck's parents come to town.

Athena, Bobby and the 118 "speed" to the rescue to save a family whose pick-up truck has been rigged with a pipe bomb which will detonate if the vehicle slows under 55 miles an hour. Meanwhile, Eddie has a rough transition into his new job, Buck makes an impulsive relationship decision and Hen is reluctant to accept her new partner in Chimney's absence.