Officer Nolan and Officer Chen search for a missing person who may have international ties that puts everyone's lives in danger. Meanwhile, Harper continues the search for a serial arsonist after responding to a report of an injured cyclist, and Wesley must overcome an impossible task.
s04e01 - Life and Death
s04e02 - Five Minutes
s04e03 - In the Line of Fire
s04e04 - Red Hot
s04e05 - A.C.H.
s04e06 - Poetic Justice
s04e07 - Fire Fight
s04e08 - Hit and Run
s04e09 - Breakdown
s04e10 - Heart Beat
s04e11 - End Game
s04e12 - The Knock
s04e13 - Fight or Flight
s04e14 - Long Shot
s04e15 - Hit List
s04e16 - Real Crime
s04e17 - Coding
s04e18 - Backstabbers
s04e19 - Simone
s04e20 - Enervo
s04e21 - Mother's Day
s04e22 - Day in the Hole
Starting over isn't easy, especially for small-town guy John Nolan who, after a life-altering incident, is pursuing his dream of being a Los Angeles police officer. As the force's oldest rookie, he's met with skepticism from some higher-ups who see him as just a walking midlife crisis. If he can't keep up with the young cops and the criminals, he'll be risking lives including his own. But if he can use his life experience, determination and sense of humor to give him an edge, he may just become a success in this new chapter of his life.