What goes around comes around for an unremorseful widower, an arrogant fitness club owner and an unsuspecting thief. Meanwhile, Bobby gets a surprising phone call from his doctor after donating at Chimney's blood drive, and Athena confronts Michael after having a heart-to-heart with their kids.

Maddie goes for a ride-along with Athena in the hopes of being on the other end of a 9-1-1 call; Hen attempts to learn how to prevent her family from falling apart at the seams; disaster strikes at a military funeral and movie theater.

Bobby meets Athena's parents for the first time and Maddie attempts to end her marriage for good, causing Doug to insinuate himself even deeper into Chimney's life. Meanwhile, a tanker carrying a tiger shark crashes on the freeway and a gas leak in a plastic surgeon's office happens mid-surgery.

The First Responders rally together to search for a missing Maddie.

Athena enlists the 118’s help when a teenager speeds out of control on the freeway. Meanwhile, a routine traffic stop uncovers a shocking kidnapping and Buck struggles with his recovery.

When a murder weapon from a case close to Athena in the early '90s resurfaces, flashbacks to 1989 show how Athena joined the LAPD and became the police officer she is today.

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.

The 118 rush to save lives in the aftermath of a massive train derailment.

Another day in the life of the 118, as its members race to rescue a cliffside wellness retreat guru after his followers turn on him. Then, they respond to an emergency call at an upscale hair salon. Meanwhile, Maddie contemplates returning to work, Eddie and May make decisions on their future, as do Buck and Taylor, and the 118 gathers for a surprise wedding.

After a victim of the apartment fire that changed Bobby’s life resurfaces, he searches to make amends. Driven by his need to right past wrongs, Bobby delves deep into memories of his childhood, unearthing moments from his fractured past.

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.

Athena and Buck are in a race against time to rescue the rest of the 118 following the fire in the bio lab.

Following the tragic events at the lab, the 118 must come together to lay their fallen hero to rest. Meanwhile, despite her own grief, Athena re-investigates the death of a child to help a grieving mother.

The 118, still reeling from their recent loss, is dispatched to a mass casualty event after a high-rise apartment building collapses. Then, Athena and Chimney have to work together to save a familiar face.