Episode #1: "El Gringo Loco" - Sept. 26, 2017
Murtaugh intercepts Riggs just as he is preparing to shoot and kill Tito, the drug lord responsible for Miranda's death. He convinces Riggs to bring Tito back to the U.S. alive, in the trunk of Murtaugh's car. When they prepare to turn Tito over to U.S. authorities, however, they open the trunk and discover Tito has been shot in the head and killed.
#2 "Dancing in September" - October 3, 2017
With Deputy Chief Gina Santos (Michelle Hurd) looking into their past cases for evaluation purposes, Murtaugh and Riggs take on a Russian drug ring. The case has Riggs reconnecting with Agent Palmer, who has been given desk work at the DEA ever since she leaked the Tito Flores file to Riggs. Elsewhere, RJ is packing for college and seems reluctant to live on campus, until he learns that his dorm building is co-ed, which then has dad and mom concerned.
#3 "Born to Run" - October 10, 2017
Riggs and Murtaugh, along with young detective Zach Bowman (Andrew Creer), investigate when the bodyguard of famous pop singer Shaye (Joanna Levesque) is murdered. The detectives uncover a secret relationship between Shaye and the bodyguard, along with an even bigger secret in Shaye's past. Meanwhile, Riggs and Palmer struggle to find normalcy in their relationship.
#4 "Flight Risk" - October 17, 2017
A lifelong con man robs the passengers on a private plane at gunpoint while it is airborne, then leaps out with a parachute, taking a victim with him. Riggs and Murtaugh learn that the con man is dying and wanted one last haul to help his daughter after he's gone, but one stolen item (a briefcase full of uncut diamonds) has attracted a group of violent criminals. Meanwhile, Santos questions Avery's ability to lead, given his top detectives' penchant for danger.
#5 "Let it Ride" - October 31, 2017
Riggs and Murtaugh investigate a death that occurs moments before the victim's bet wins a horse race. The victim is Howard, a friend of Leo Getz. While it appears that Howard had a stroke, Getz is convinced it's murder, which Scorcese later proves to be true. Meanwhile, the city tows Riggs' trailer off the beach, bringing back painful childhood memories of being evicted.
#6 "Gold Rush" - November 7, 2017
Riggs helps his childhood friend Jake (Linds Edwards) get paroled from prison, but it soon becomes apparent that Jake is up to no good again. Seeing how Riggs gives Jake a lot of leeway, Murtaugh asks his partner if he owes his old pal a favor. Elsewhere, Murtaugh tries to find out which of his family members left a marijuana joint in a package of cookies, while Bailey deals with the aftermath of accidentally sending a sext to Bowman.
#7 "Birdwatching" - November 21, 2017
Riggs and Murtaugh work on the case of a dead surfer who just came into town from San Diego the day before. Bailey and Bowman help, and Bailey wonders why Bowman is treated like a hero in the beach town. Meanwhile, Murtaugh becomes suspicious of Trish's relationship with her charity ball co-chair "Scott", until he learns it is ex-NBA star Scottie Pippen. Also, Riggs deals with recurring nightmares.
#8 "Fork-Getta-Bout-It" - November 28, 2017
Riggs and Murtaugh investigate a murder involving a couple and a New York mobster, Frank Truno. Scorsese reveals a movie script he has been writing, after he found out that the case revolves around the mafia. However, Murtaugh dislikes the way Scorsese accurately portrays him as one of the characters. Meanwhile, Riggs is taken aback when his childhood friend Molly (Kristen Gutoskie) suggests that they could have been romantically involved.
#9 "Fools Rush In" - December 5, 2017
A man with schizophrenia who believes that Elvis Presley is controlling the hollywood's traffics is running away from Riggs and Murtaugh when he was suspected to kill a man. However, when he proves his theory, Riggs and Murtaugh must stop an organized heist conducted by men dressing as Elvis Presley. At the same time, Murtaugh tries to get his daughter into at an esteemed pre-school and Riggs contemplates the possibility of a romantic relationship with his childhood friend Molly.
#10 "Wreck the Halls" - December 12, 2017
Murtaugh is ready for his family holiday in Hawaii until Diego, a young man he once helped, is murdered. Riggs and Murtaugh confront Grant Davenport (Martin Donovan), the president of an American upper class club where Diego is employed, who has ties to the Aryan fraternity. However, their confrontation causes the fraternity to ambush both of them. Murtaugh manages to subdue his attackers, but Riggs is only able to escape because of his father's assistance.
#11 "Funny Money" - January 2, 2018
Riggs and Murtaugh take on a counterfeiting ring and are joined on the case by veteran Secret Service Agent Peterson (Ernie Hudson). A group of three teenagers inadvertently get involved when they witness a shooting and run off with the phony cash and plates. One of the teenagers named Ty (Nathan Davis Jr.) strikes a chord with Riggs after revealing he's homeless. Meanwhile, Riggs brings home a dog for Ben and Molly. Molly later finds the dog dead with its neck snapped. Sensing it's a message from his father, Riggs goes to confront him in prison. Also, Roger and Trish learn that RJ has been cutting classes at college.
#12 "Diggin' Up Dirt" - January 9, 2018
Shortly after Gene Nakahara (C.S. Lee) meets with Trish and an uninvited Leo Getz to announce he is running against Councilman Sean O'Brien (Michael Reilly Burke) for Mayor of Los Angeles, Gene is killed when his car blows up. Riggs and Murtaugh learn of a private investigator named Serrano (Tim Kang) who works as a "fixer" for high-profile people and investigate that angle, while Trish and Leo work behind the scenes to reveal skeletons in O'Brien's closet. Riggs also learns that his late wife Miranda once visited Serrano to get info on Riggs' father.
#13 "Better Living Through Chemistry"
January 16, 2018
Dr. Cahill begins to question her abilities when two patients of hers die in separate incidents, until it is learned that they were briefly roommates in the same psych facility. Riggs and Murtaugh uncover corruption in the facility related to the meds both patients were taking. At the same time, Santos learns that Riggs had an anger incident caught on tape in which he destroyed the deputy mayor's car, and requests that Cahill sign an affidavit confirming that Riggs is still fit for duty. Elsewhere, Trish and Roger see that RJ has become depressed and withdrawn after dropping out of college, and decide to take their son to a therapist.
#14 "Double Shot of Baileys" - January 23, 2018
Detective Bailey's younger sister Jess (Alisha Wainwright) inadvertently gets caught up with a drug mob when she and her boyfriend use her waitress position at a high-end night club to steal a man's wallet. After the boyfriend is killed over the wallet's contents, Bailey walks a thin line between her obligation to the law and protecting her sister. Elsewhere, Murtaugh helps Riana spy on her boyfriend, whom she accuses of cheating, while Riggs loses his truck after a night of heavy drinking.
#15 "An Inconvenient Ruth" - February 6, 2018
A elderly drifter named Ruthie (Swoosie Kurtz) is present at a jewelry store robbery, and becomes a key witness in the case. In the process, she and Riggs, who has recently vowed to stay sober, bond over their alcoholism. Meanwhile Murtaugh, fresh off being called "grandpa" at the playground while with his toddler, starts acting like Riggs and takes dangerous risks to prove he's not getting old. This gets him on Trish's bad side.
#16 "Ruthless" - February 27, 2018
Riggs and Murtaugh track a group of criminals who stole numerous guns during a shoot-up at a police buy-back event. They locate and capture the group's leader, Booker (Sheaun McKinney), only to learn that he's working undercover for ATF. Avery learns from Booker's boss that Booker is a bit of a loose cannon, much like Riggs. Meanwhile, Riggs learns a little more about Ruthie's past and family situation, as Roger and Trish continue to fight at home.
#17 "The Odd Couple" - March 6, 2018
With Riggs trying to get Murtaugh to make up with Trish and get out of his trailer, the two only make things worse when they ruin a public building implosion for Trish's latest project by tailing a murder suspect and tackling him on the stage. An angry Trish tells the two that her client, grocery store magnate Henry Butler (Michael McGrady), now wants to bail on the project. Riggs convinces Butler to stay in town to enjoy Molly's barbecue. Riggs and Murtaugh discover that Butler, not the man they have in custody, is behind the murder, and Trish eventually also learns that her client is dirty. This leads to a wild adventure when Riggs and Murtagh board Butler's private jet as he's trying to flee. While thanking Molly for her help, Riggs says he wants more out of their relationship than just friendship, but Molly insists that Riggs resolve the issues with his father first.
#18 "Frankie Comes to Hollywood"
April 10, 2018
In a flashback to more than 16 years ago, Frankie Kelso (Jude Ciccolella), a contract killer who frequently worked with mobsters, is shown having mercy on Murtaugh after Roger tried to arrest him at the scene of a hit. He lets Murtaugh go when the latter tells him that his wife is delivering their baby daughter (Riana) at that very moment. In the present, Murtaugh notices Kelso's signature at the scene of another killing. He captures Kelso, but Kelso is again able to get the upper hand and take Murtaugh hostage. Kelso insists that he left his old life behind and that someone framed him for the recent crime. Riggs recognizes the name of one of Kelso's mob connections as someone who spent time in prison with his father, Nathan, and he reluctantly contacts Nathan to get the information he needs to save Roger. Nathan is soon stabbed by the mobster's colleagues in prison, and is hospitalized. A nurse tells Riggs that Nathan will probably recover and live this time, but that the gang has declared war on him for snitching to Martin. She suggests he use his pull as a police detective to get his father moved to another facility. Riggs is left pondering what to do, considering the self-sacrificing act his father just did as compared to his life of selfishness and abuse when Martin was young.
#19 "Leo Getz Hitched" - April 17, 2018
Leo is getting married to Nina, an ex-con, but she is a no-show on the day of the wedding. Riggs and Murtaugh find her with a group of criminals trying to unload a bag of cocaine that "fell into" her purse at a high-stakes poker game run by a known mobster. At the same time, Riggs learns that Molly met with her ex-husband Jake, who is still a fugitive, and that Jake was at the same poker game. When Riggs catches up with Jake and asks why he's in town, Jake says it's for "work". It turns out that Jake is planning to rob the safe at the poker game with two other conspirators. Elsewhere, Murtaugh is distraught over finding a positive pregnancy test in the trash can outside his home.
#20 "Jesse's Girl" - April 24, 2018
A break-in at a mansion turns deadly, and Roger and Trish are surprised to learn that Riana may be involved. It turns out that Phoebe, the sister of Riana's new boyfriend Jesse, is in possession of stolen diamonds from the heist and has become a target. Meanwhile, Riggs tries to be a good father figure for Ben, as he recalls the things he and Molly discussed in their teen years.
#21 "Family Ties" - May 1, 2018
With Avery away at a conference, Murtaugh is appointed interim captain. His first case involves the kidnapping of Lisa Conlon, wife of a pharmaceutical magnate. Riggs is forced to get his father involved when it's revealed that the Aryan Fraternity of Texas (AFT) is behind the crime. In the process, Riggs learns that he has a 19-year-old half-brother, Garrett, who is assisting the AFT. In exchange for his help, Riggs' father is let out of prison early. His comments to Riggs suggest that he plotted the whole kidnapping to get an early release. Meanwhile, Commissioner Debra tells Murtaugh that he is being promoted to full-time captain, as Avery will not be returning.
#22 "One Day More" - May 8, 2018
While Murtaugh visits Riggs, Riggs' trailer is shot up by two men on motorcycles. A neighbor gets a plate number from one of the bikes, which is registered to Grant Davenport's business. When Riggs and Murtaugh confront Davenport, he says the bike belongs to his security team, which Martin finds out includes Nathan. Nathan is shown confronting Davenport to get bail money for his son, Garrett. Later, Martin is tailing a suspect on a motorcycle and captures him. The man says that Murtaugh was the target in the trailer shootout, not Martin. Martin then learns that the senior partner Trish works for has been laundering money for the AFT drug trade. Nathan shoots Trish's boss, then takes Trish hostage. Martin and Roger determine the only way to save Trish is to get Garrett out of jail and exchange his life for hers. At the exchange, Martin and Nathan fight, which leads to Martin killing his father as Garrett runs away. With everyone now safe, Martin reveals the news that he's moving back to Texas with Molly and Ben. Before meeting up with Molly, Martin stops at Miranda's grave to say goodbye. As Martin turns to leave, Garrett walks up and shoots him once in the chest.