The 118 responds to a skydiving trip gone wrong, a bank rep injured in a home repossession and a lovestruck assistant whose lunch run ends in disaster. Meanwhile, Athena and the family come to terms with Michael’s difficult health decision and Chimney’s half-brother from Korea unexpectedly shows up at his doorstep.

The 118 races to rescue a little girl in a runaway hot air balloon and help with a city power outage caused by a hijacked tree-trimmer truck; Athena's investigation into a serial rapist case puts her life in jeopardy.

In the aftermath of the dam break, massive mudslides wreak havoc throughout Los Angeles.

The 118 responds to a series of calls dealing with parents and their children, including a disastrous birthday party thrown by a mommy blogger. Meanwhile, Athena and Michael talk to May about her past suicide attempt, Chimney and Maddie adjust to life with their newborn, and Hen and Karen are emotionally shattered as their foster daughter, Nia, is reunited with her birth mother.

While in Florida caring for her ailing father, Athena and Bobby investigate the disappearance of her childhood friend from 45 years ago.

As Buck's life hangs in the balance, he dreams of a world where he never became a firefighter, for better and worse.

The 118 race to rescue two roommates desperately trying to find a needle in a haystack at a landfill, and help a woman whose nightmare dream suddenly becomes a painful reality. Athena and Maddie team-up to find a missing boy in a crowded mall; Chimney debates if the time is right to propose to Maddie.

The disastrous cruise continues when Bobby and Athena respond to the ship's explosion, racing to aid injured passengers. Meanwhile, Hen questions her instincts in a life-taking call and grows concerned about Athena and Bobby's whereabouts.

With each moment becoming critical as the ship is flipped upside down, Athena and Bobby take charge, seeking methods for rescue while navigating efforts to guide survivors to safety. Meanwhile, Hen defies protocols in her search for Bobby and Athena.

Hen and Karen welcome a new addition to their family, while a call unfolds involving a person’s limb that’s taken on a mind of its own. Meanwhile, Eddie and Marisol take a closer look at their relationship, and Buck navigates his new feelings.

Following the devastating fire at the Nash home, Bobby's fate remains uncertain, while Athena embarks on a mission to uncover the truth. Meanwhile, Hen and Karen engage in a heated custody battle, while Christopher grapples with forgiving Eddie.

When it finally looks like Hen and Karen may get their foster license back, they are hit with another obstacle. Meanwhile, the 118 races to the aid of a Cheerleader involved in an infield collision.

When Athena is assigned a rookie to mentor, she begins to question her own abilities. Meanwhile, Bobby and the 118 return to the set of "HOT SHOTS" following a 911 call.

After the 118 responds to several calls from the same person, Hen steps in to offer them advice. Meanwhile, Eddie confronts his parents and takes a big step in his relationship with his son.

In part one of a two-part episode, the 118 is called to a research lab that has been set on fire and becomes a biohazard.