When Wesley Cole returns home and assumes duty as a LAPD police officer, the former international CIA operative finds himself navigating a new partnership with Murtaugh as he adjusts to life in Los Angeles. Meanwhile, Avery continues his campaign for city council.
New partners Murtaugh and Cole attempt to find a steady rhythm as they work to solve the murder of a finance executive. Meanwhile, Cole navigates his role with his ex, Natalie, and his daughter, Maya, and Avery grapples with the outcome of his campaign for city council.
Cole juggles the realities of his job and his duty to be a good parent as he and Murtaugh work together to bust a gang running a lottery scam. Murtaugh prepares to celebrate his 30th year with the LAPD and receives a surprise visit from his competitive father-in-law.
Cole reflects upon his time working for the CIA, as a person from the past makes a startling reappearance. Murtaugh struggles with his own mistakes after a murder raises questions about a suspect he put away years prior; and Leo Getz returns as the attorney on the case.
Murtaugh and Cole investigate after a robbery of a truck filled with fine art. Cole deals with lingering feelings for Natalie after a development in her life. Meanwhile, Riana blackmails Murtaugh into letting her go to a concert after she catches him in a lie.
Cole confronts his past when his former mentor, Tom Barnes, delivers alarming news, as he and Murtaugh investigate a robbery of safe deposit boxes. Meanwhile, Murtaugh clashes with Trish's new client, Louie Gutierrez, and enlists Bailey's help to investigate her.
Murtaugh turns to Cole's former mentor, Tom Barnes, for help on a high-stakes cartel case. Meanwhile, Murtaugh and Trish meet Natalie and Maya for the first time, and tensions mount between Bailey and "The Gute" as the new partners begin to work together.
Cole wants to talk to Natalie about their relationship before it's too late, but a wrench is thrown in his plans after he bumps into a new ADA, Erica. Meanwhile, after being kicked out of the house for Trish's girl's night, Murtaugh finds himself an unlikely friend.
While Cole gets into the holiday spirit for his first Christmas with Maya, Murtaugh hopes he can convince RJ to come back home from Costa Rica for the holidays. At the precinct, Cole and Murtaugh are saddled with a complicated burglary and home invasion case.
Cole finds himself on the rebound, and his new romantic interest has an unexpected connection to the A.D.A., complicating things at work. Meanwhile, Murtaugh worries about the connection between a case he's working and an opportunity for Trish on a high-profile lawsuit.
Murtaugh takes a family vacation, but is pulled back into work when he witnesses an alleged abduction. Cole is left to investigate a murder himself, but the two cases begin to intersect.
Murtaugh and Cole investigate the murder of an underground MMA fighter when Murtaugh realises his fighting moves aren't as sharp as they once were. Meanwhile, Trish is unfulfilled by her practice and considers running for a public office.
When Cole and Murtaugh investigate a case involving a father and daughter crossing the Mexican border, they end up uncovering a major issue with California Boarder Patrol. Meanwhile, Trish prepares her campaign for D.A. and must face parts of her past.
Against Murtaugh's advice, Cole reaches out to Tom Barnes to help with a case that hits close to home, putting Murtaugh and Cole's partnership to the test. Meanwhile, Trish prepares to announce her campaign for District Attorney.
When Cole is investigated by the FBI, Murtaugh is forced to question his loyalty to his own partner. Meanwhile, Cole works a case that puts Natalie's fiance, Andrew, into the crosshairs right before their wedding day.