The new Seattle fire chief is introduced to Station 19 and leaves the crew skeptical after his visit. Later, the firefighters are called to a department store fire caused by exploding fireworks, which triggers painful memories from Ben’s past and inspires him to pursue a new endeavor. Maya advocates for herself and her career, while Jack becomes more intertwined with an acquaintance; and Andy and Ryan have a heart-to-heart.

While Pruitt grieves a monumental loss, Andy refuses to do the same and, instead, throws herself into work. Meanwhile, the crew responds to a widespread carbon monoxide leak, and Sullivan makes a controversial choice for captain.

Ben and Jack mollify a group of homeless foster and biological siblings so they can help save a life, triggering memories from Jack’s past. Meanwhile, Maya pushes the team too hard and struggles to bring them together; and Pruitt threatens to take drastic action when refused a request.

In an effort to increase morale, Maya takes the crew on a team-building camping trip that doesn’t exactly go according to plan. Their bond is put to the test as they work to save first-time campers after a gruesome bear attack. Meanwhile, Pruitt takes steps to repair his relationship with Andy, and Sullivan goes to extreme lengths to find relief from the pain in his leg.

When a blizzard hits Seattle, Travis must take a difficult call and members of the crew are forced to face their truths. Meanwhile, Ben has rising suspicions about a colleague.

As Ben readies the new Physician Response Team truck for the field, his suspicions about Sullivan and the missing Fentanyl continue to grow. Meanwhile, Jack and Rigo try to look past their differences when they are forced to work together and fight a mysterious gas station fire; Dean and JJ try to work through their differing parenting styles; and Travis meets someone new.

After some tense and traumatic experiences, the firefighters get a visit from a psychologist .

Vic rallies the crew to pose for a calendar photo shoot that will support a good cause. Meanwhile, Emmett comes clean to Ben and Sullivan, and shows Andy a softer side.

Maya and Theo answer a call at a Halloween carnival; but when fire hits the corn maze, the dangers quickly escalate and Maya risks her own life to prove her worth to her increasingly hostile captain. Meanwhile, Station 19 hosts the neighborhood kids for trick-or-treating; a prank war breaks out in the house, and Jack is haunted by a ghost from his past.