Riggs and Murtaugh are forced to work with DEA agent Karen Palmer—again— to protect Leo Getz, an ambulance-chasing attorney who was linked to the Cartel. As the three delve further into the case, they begin to realize that Leo may not be the only one with a target on his back. Riggs begins to view Agent Palmer in a new light. Murtaugh is left worried after Trish makes a spontaneous decision.

Murtaugh and Riggs investigate a death that occurs moments before the victim's bet wins a horse race. Leo Getz insists it's a homicide and aids in the investigation. Murtaugh updates his will. Riggs struggles to come to terms with his past.

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.