Better Living Through Chemistry
An escaped patient of Dr. Cahill’s is murdered; Riggs’ anger gets the better of him; Avery considers whether he is fit to serve; family tension runs high between Murtaugh and Trish when they have to make big decisions about R.J.
Diggin’ Up Dirt
When Riggs visits his father-in-law in prison, an old secret about his deceased wife comes to light; Murtaugh tries to impress Capt. Avery; Trish and Leo Getz try to solve a murder on their own.
Riggs and Murtaugh are thrown into the world of counterfeit money. When a group of teenagers inadvertently gets involved, it strikes a chord with Murtaugh, who is dealing with his own issues regarding his son, RJ. Meanwhile, Riggs decides to pay a visit to someone from his past.
Wreck the Halls
The Murtaugh family heads to Hawaii for Christmas; the vacation is put on hold when Murtaugh and Riggs are called to investigate a homicide; Riggs gets a surprise phone call from a relative just in time for Christmas.
Fools Rush In
Riggs and Murtaugh are drawn into a world of conspiracy theories; Riggs’ relationship with Molly evolves; Murtaugh and Trish try to get Harper into a fancy preschool.
Riggs and Murtaugh are led into the mob world as they investigate a murder in a hospital; Murtaugh learns that Riana is secretly dating his neighbor; Riggs spends more time with his childhood friend; Scorsese’s real name is revealed.
Riggs and Murtaugh investigate a surfer’s death; Murtaugh grows suspicious of Trish’s new friend; Riggs has violent nightmares.
Riggs’ childhood friends may be involved in a robbery-homicide case; Murtaugh thinks one of his kids is using marijuana.
Let It Ride
Murtaugh and Riggs investigate a death that occurs moments before the person is going to win a horse racing bet; Leo Getz insists it’s a homicide; Murtaugh updates his will; Riggs struggles with his past.
Murtaugh and Riggs respond to a robbery that took place 20,000 feet in the air; Murtaugh’s attempts to connect with his daughter are met with hostility.