A blackout in Seattle creates dangerous situations throughout the city and the members of Station 19 head out on calls, including locating a missing girl and helping a man on life support where every second counts.

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.

Vic and Travis’ friendship is put to the test as they respond to calls to help two best friends in need. Meanwhile, Jack realizes he has a greater impact on Marcus than he realizes, and new details about Travis’ late husband’s tragic death are revealed.

Relationships are challenged at Station 19 following Sullivan’s actions at Maya and Carina’s wedding, putting his marriage with Andy to the test. Dean comes to terms with his feelings for Vic, while Travis rekindles an old flame. The annual Phoenix Festival brings out some reckless behavior in some of Seattle’s citizens, challenging the teams at Station 19 and Grey Sloan Memorial.

The crossover continues on Grey's Anatomy S18E01 Here Comes the Sun (II).

The crew at Station 23 faces a difficult goodbye. Meanwhile, Andy meets a charming firefighter, and Emmett invites Travis to have dinner with his parents.

Andy tracks down a witness to testify at her trial. Meanwhile, Carina and Maya deal with a stressful situation, and the crew responds to a car wreck.

The Station 19 crew jumps into action as a violent tornado rips through Seattle. Amidst the chaos, the team makes a shocking discovery buried under a tree, and Travis' first responder instincts kick into high gear at a political event.

Emotions boil over at the station as the team chafes against Theo’s leadership style. Carina enlists Ben and Maya to help her with a patient in an uncomfortable position. Natasha and Sullivan’s relationship hits a roadblock.

The Station 19 crew trade in their turnouts for tuxes and gowns as they attend the Firefighters Ball, but when disaster strikes, they jump into action to save the day.