
As Athena fights to save herself and an agoraphobic woman after her house collapses, Bobby, Hen and Eddie rush to save hikers endangered by the falling of the Hollywood sign.
In the aftermath of the dam break, massive mudslides wreak havoc throughout Los Angeles. Maddie must first locate, and then rescue, a trapped cyclist, and Athena helps an agoraphobic woman evacuate her home. When the Hollywood Reservoir dam breaks, Bobby and the 118 race into action to save passengers on a city bus that has crashed into a building several stories in the air.
More on Bobby and Athena's marriage and something that will lead him to questioning how much she needs him, leading to a strain in their relationship. A "new phase" for Buck, on moving on from Abby after the events of " What's Next?". A secret that Maddie has been keeping about her and Buck's childhood will lead into " Buck Begins". The storyline of Maddie and Chimney's relationship continuing, and the steps they go through during her pregnancy. After a devastating 7.1 earthquake and coastal tsunami wreaked havoc in the city, what could possibly be next? Meanwhile, among the chaos, Athena is determined to put her physical and emotional injuries behind her and jump back into the job, as Maddie and Chimney prepare for the birth of their baby, and Buck delves into his past to help deal with his present.