第 4 季 共 24 集
播出时间：2012年9月26日
第 1 集 Endgame
播出时间：2012年9月26日
Following Callen’s public shooting of the Chameleon, all is not well with the NCIS: LA team, as Callen is placed on suspension and Hetty adjusts to retired life.
第 2 集 The Recruit
播出时间：2012年10月3日
A drone strike on a bomb-making compound in Afghanistan reveals the body of a recently retired Marine, leaving the NCIS: LA team to investigate why the Marine returned to Afghanistan and whether or not he betrayed the country he fought for.
第 3 集 The Fifth Man
播出时间：2012年10月10日
The NCIS: LA team investigate a compromised intel operation after four people connected to the classified project are killed at a diner explosion. As Deeks and Kensi are on the trail of those involved, they learn that a wayward teenage girl might be related and Kensi can’t help but be empathetic to her situation.
第 4 集 Dead Body Politic
播出时间：2012年10月24日
The NCIS: LA team investigates the tragic death of a U.S. senatorial candidate’s staffer who is run over crossing the street. The high-profile case becomes a matter of national security as the agents must determine whether it is an isolated tragic incident or a politically connected plot that might put others in danger.
第 5 集 Out of the Past (1)
播出时间：2012年10月31日
When a CIA agent who worked with Sam Hanna over eight years ago seeks his help and is soon found dead of an apparent suicide, Hanna and Callen suspect foul play and a bigger conspiracy. Meanwhile, Deeks finds his inner “dog whisperer” with Kensi as the two go undercover and enter a dog show with a prized poodle.
第 6 集 Rude Awakenings (2)
播出时间：2012年11月14日
The NCIS: LA team continues their investigation behind the death of a CIA agent that leads to a dangerous ring of Russian super agents. In a race against time, Hanna risks having a secret exposed.
第 7 集 Skin Deep
播出时间：2012年11月21日
The NCIS: LA team heads to the beach to question the possible link between a surfer, an Internet video and a dead Naval tech scientist. Meanwhile, as Callen and Hanna investigate the victim’s intelligence connections, Deeks and Kensi go undercover to catch their suspects and some waves.
第 8 集 Collateral Damage
播出时间：2012年11月28日
The NCIS: LA team questions the motive behind the murder of a retired CIA agent turned millionaire and in the process also questions what Hetty knows about the case.
第 9 集 The Gold Standard
播出时间：2012年12月12日
The NCIS: Los Angeles team investigates the strange and brazen heist executed by gunmen in costumes that could directly impact the U.S. economy. Meanwhile, as Deeks testifies on a case, Granger insists on partnering up with a very reluctant Kensi.
第 10 集 Free Ride
播出时间：2012年12月19日
Callen, Sam, Kensi and Deeks spend Christmas aboard an aircraft carrier investigating the death of a fellow NCIS special agent. Meanwhile, Nell and Eric make the most of the holidays back at headquarters and Hetty takes a trip.
第 11 集 Drive
播出时间：2013年1月9日
A former defendant of Deeks is targeted for discovering information that could dismantle a lucrative car shipping operation with links to a global terrorist ring. Meanwhile, the NCIS: LA team tackles the large-scale stolen car operation from the inside when Kensi goes undercover in an auto body shop.
第 12 集 Paper Soldiers
播出时间：2013年1月16日
A distraught widow is suspicious of the circumstances surrounding her Marine husband’s last battle and Sam and Callen help to determine if there has been a cover-up. Meanwhile, Hetty summons Operational Psychologist Nate Getz to be her “pawn” and the rest of the NCIS: LA sense another evaluation on the horizon.
第 13 集 The Chosen One
播出时间：2013年1月30日
Callen goes undercover to infiltrate a network of Chechen terrorists who are recruiting foreign fighters to join their cause and planning their next attack in the U.S.
第 14 集 Kill House
播出时间：2013年2月6日
Callen, Sam, Kensi and Deeks go undercover as an elite tactical force in order to investigate an ambush tied to a cartel kingpin with terrorist connections.
第 15 集 History
播出时间：2013年2月20日
An NCIS: LA investigation leads the team to question a lone survivor of a former terrorist organization, while Kensi and Deeks follow the trail into the woods
第 16 集 Lohkay
播出时间：2013年2月27日
Callen is concerned that Sam might be too invested after he takes on a missing persons case for an Afghani elder who helped him years ago when he was wounded on a mission.
第 17 集 Wanted
播出时间：2013年3月6日
Sam fears for his family’s safety when his wife is called to resume a former CIA cover after a case suggests ties to the infamous Sidorov and his stolen nuke.
第 18 集 Red (1)
播出时间：2013年3月20日
Callen and Sam fly to Idaho and join forces with NCIS: Red, a mobile team of agents who live together and investigate crimes in various locations, when a murder weapon found there matches one used in a national security case in Los Angeles.
第 19 集 Red (2)
播出时间：2013年3月27日
While the LA team chases leads digitally and locally, the NCIS: Red team travels in their mobile trucks, nicknamed "Laverne and Shirley", in a race to track down a cunning terrorist before he disappears.
第 20 集 Purity
播出时间：2013年4月10日
When cyanide in a communal water jug lethally poisons a lieutenant and leaves a Navy pilot in serious condition, the NCIS: LA team investigates whether this is an isolated incident or an early test for large-scale water contamination.
第 21 集 Resurrection
播出时间：2013年4月24日
A body is stolen after a special task force successfully takes down an infamous cartel boss, leaving the NCIS: LA team to investigate the leak and track down the missing body.
第 22 集 Raven & the Swans
播出时间：2013年5月1日
Callen questions Hetty’s motivations when a bizarre case involving a mysterious woman is revealed to be an undercover agent from her past.
第 23 集 Parley
播出时间：2013年5月8日
Deeks goes undercover to obtain information about an infamous arms dealer looking to get back in the business, but the woman he befriends leads the operation in a dangerous directon. Meanwhile, Kensi confronts new emotions as she runs surveillance on Deeks and his female source.
第 24 集 Descent
播出时间：2013年5月15日
A nuclear explosion in the Pacific reignites the search for stolen nuclear weapons and prompts Hetty to shuffle the NCIS: LA partnerships, sending Callen and Kensi overseas and leaving Sam and Deeks teamed up state side.
