Former international CIA operative Wesley Cole returns home and becomes Murtaugh's partner on the force; Avery continues his campaign for city council.

Murtaugh and Cole try to find their stride as they work to solve the murder of a finance executive; Cole navigates his role with his ex, Natalie, and his daughter, Maya; Avery grapples with the outcome of his campaign for city council.

Cole and Murtaugh try to balance their family lives with their efforts to bust a gang running a lottery scam.

Cole and Murtaugh look back on past mistakes as Leo Getz returns as the attorney on their latest case.

Cole needs to talk to Natalie about their relationship. Murtaugh makes an unlikely friend.

Cole finds himself on the rebound after Natalie's engagement; Murtaugh worries about the connection between the murder he's investigating and an opportunity for Trish to serve as co-counsel on a high profile lawsuit with Leo Getz.

Murtaugh's witnessing of an alleged abduction and Cole's investigation of a murder begin to collide; Erica's mother comes to town and stirs things up between her, Cole and the case at hand.

Murtaugh realizes his fighting moves aren't as sharp as they used to be when he and Cole investigate the murder of an underground MMA fighter; Trish considers running for public office; Cole and Erica try to keep things casual.

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.

Cole is investigated by the FBI, forcing Murtaugh to question his loyalty to his own partner; Cole works a case that puts Natalie's fiance into the cross-hairs right before their wedding day.