A massive tsunami hits the Santa Monica Pier, placing Buck and Christopher's lives in danger .

Athena, Maddie, Bobby and the 118 races to save lives after a massive tsunami hits the Santa Monica Pier and Buck fears the worst when Christopher goes missing.

Maddie fears for herself and her co-workers when the call center is taken hostage.

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.

Emergencies include a skating mishap at an ice show, an accident involving a self-driving car and a fulfillment warehouse robot going rogue. Meanwhile, Eddie's after-hours fight club gets out-of-control and Hen struggles in her relationship with Karen.

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

Eddie's journey to rescue a boy from a well turns into a mission to save himself from his past.

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 fights an apartment building blaze; Athena's response to an accident call leads to a more sinister crime; Hen performs a risky medical procedure during a televised cooking show; Buck is inspired to reunite with his lost love.

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.

Holiday-themed incidents include a shopper pushed over the edge, a woman who is literally having a "Blue Christmas" and a luggage handler accident on a tarmac; Maddie revisits her past to embrace her future; Bobby receives shocking news.

Accidents happen at a bowling alley and a home renovation; Athena pursues a car thief.

Athena and the 118 respond to bizarre emergency calls on Halloween, including a flock of crows terrorizing a field trip, an office employee having a close encounter with an eight-limbed creature and a ghost-like girl wandering a neighborhood.

The 118 responds to debris from a meteor shower crashing into an apartment building and a deadly fire caused by a hazardous waste truck crash inside a tunnel. Meanwhile, Hen struggles with guilt over her ambulance accident, Bobby introduces Eddie to an old friend to help with his anger and Maddie receives an urgent call for help.

The 118 responds to a viral stunt gone haywire, a disaster at a couple’s fishing trip and an epic first date fail. Meanwhile, Athena investigates a woman who doesn’t remember being shot in the head and Eddie is forced to have a difficult conversation with Christopher.

The 118 races to help protesters at a slaughterhouse and a wife who finds herself trapped in a “rage room” with her husband’s mistress. Athena takes action after Michael, May and Harry experience a traumatic traffic stop.

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 team races to save workers in a high-rise during a fire drill, car accident victims, and siblings fighting over a family heirloom. Buck gives Bobby surprising news. Eddie helps Christopher deal with the trauma caused by the tsunami.