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.

The 118 race to the rescue at a renaissance faire, then an office building when an overbearing boss is poisoned. Athena fears for May's life when she encounters a disturbed young man. Buck babysits Jee-Yun as Maddie and Chimney begin house-hunting. Eddie and Carla prepare Christopher for his first school dance.