The whole precinct’s holiday celebrations are cut short when they’re called to examine a ruthless homicide.

Riggs and Murtaugh team up again with Palmer, and together they gain inside knowledge of dangerous new cartel operations. As Riggs’ attachment to Palmer deepens, so do his impulsive actions, further worrying Avery and Delgado. Trish explores the potential of an amazing new career opportunity.

Riggs makes a shocking discovery about Miranda’s death that leads him back to the cartel in a frantic search for answers. His wild desperation leaves Murtaugh torn between his commitment to his partner and his commitment to his family.

Riggs and Murtaugh are led into the underground mob world as they investigate a murder in a hospital. Murtaugh learns that Riana is secretly dating his neighbor and nemesis' son. Riggs spends more time with his childhood friend. Scorsese's real name is revealed.

It's Christmas time and the Murtaugh family is headed to Hawaii. Murtaugh's vacation is put on hold when he and Riggs are called to a homicide and the victim is an old friend. Riggs gets a surprise phone call from a relative just in time for Christmas.

When Riggs and Murtaugh attend Leo Getz's surprise wedding, they end up investigating a missing person. Riggs comes face to face with someone from his past. Murtaugh receives news that might change his life forever.

Former international CIA operative, Wesley Cole returns home and assumes duty as a police officer with the LAPD. Cole will find himself navigating a new partnership with Murtaugh, as he adjusts to life in Los Angeles. Avery continues his campaign for city council.