It's Christmas time and the Murtaugh family is headed to Hawaii. However, Murtaugh's vacation is put on hold when he and Riggs are called to a homicide and the victim is an old friend.
Riggs and Murtaugh are drawn into a fatal world of conspiracy theories. Meanwhile, Riggs' relationship with Molly evolves and Murtaugh and Trish attempt to get Harper into a fancy pre-school .
Riggs and Murtaugh are led into the underground mob world as they investigate a murder in a hospital. Meanwhile, Murtaugh learns that Riana is secretly dating his neighbor and nemesis' son.
Riggs and Murtaugh investigate the death of a surfer. Meanwhile, Murtaugh grows suspicious of Trish's new friend, with whom she's been working on a charity event - and then learns it's NBA champion Scottie Pippen.