The LAPD releases G after an overnight stay in jail; Sam meets him; the two exchange words; G leaves in a taxicab with a tail. At the boatshed Kensi and Deeks talk with Atley, who describes certain matters, including an insurance policy nearby; while Sam watches, an Iranian briefly chats up G, who soon walks away; another Iranian approaches Hetty, but she brushes him off; later G sees the two Iranians together, and he makes a deal with them; the CIA demands an immediate arrest of G; Granger asks Nell for a warrant for both murder and treason; Deeks picks up an item from a bank, company pursues, and fireworks ensue; Deeks drops a briefcase, and an Iranian picks it up; Eric snoops and produces; the Iranians beat and question G; Sam, Kensi, and Deeks make a road trip and take a passenger; the team make another swap; Sam hands G's badge and piece back to him; Hetty returns to her office, and Granger returns her resignation; the two of them chat about their "audacious plan".

In Afghanistan a terrorist avoids a drone strike, but a discharged Marine dies; G and company investigate; Eric and Nell learn about more unaccounted former servicemen; the foursome go to Dubai and beyond, where they work out everything.

Four men die in an explosion of an otherwise empty diner in Pasadena; all four took part in a program of the Office of Naval Intelligence; the fifth participant, who's someone else, survives; two more die; G and team figure out all of it.

A man dies in a deliberate hit-and-run incident; the victim was a staffer of a candidate for the US Senate; G and company investigate; Kensi goes undercover as the replacement for the vic; the team solve the puzzle and nail the bad person.

Sam receives a call at home. A former colleague is in trouble that might have connections to a past case.

After the decryption of a list of names, NCIS agents continue the search for both Sidorov, a Russian illegal-arms dealer, and leftover Russian sleeper agents with access to surreptitious nuclear bombs; NCIS teams execute concurrent arrests in seven cities around the USA; however, all seven teams find their targets already dead. G and Sam confer with Arkady; afterward G and Sam meet a tail, which consists of three CIA agents, one of whom, Snyder, Sam knows and dislikes; Kensi, Deeks, and others uncover an empty but radioactive secret room; Eric and Nell find Sidorov; Granger gives an order, but Sam pursues another idea, and Granger catches the team, yet he goes their way; the team watch Sidorov; Sam goes undercover, then he and his wife meet with Sidorov; Snyder allows Sidorov to leave the country (without bombs), but he expects him to return; Sam and Snyder walk into the surf at Santa Monica Bay, where the two of them discuss a disagreement.

A man stops an ambulance, kills the EMTs, stabs the patient, and removes an object from his chest; the victim was a civilian scientist working for the US Navy; G and Callen put the puzzle together and find both the killer and the object.

A retired CIA agent dies when a lighter explodes; G and company investigate because Hetty requests the case; the fearless foursome check out high-priced call girls and more, and they defy orders, but they find the truth and the bad person.

Deeks is away to testify in court, so Granger teams with Kensi. A gang stop an armored truck, attack the crew, and steal the cargo, consisting of 100 gold bars, valued at $70M, en route to the People's Bank of China; footage abounds; Callen and company investigate. G and Sam find a dead clown, and Nell IDs him; G, Sam, and Kensi find three executed thieves; Kensi talks with the girlfriend of the sole surviving thief (Welch), then she, G, and Sam find Welch's body, and Kensi finds the gold; G and Sam check the gold, which is not gold. Hetty comments to G in private that this case involves more than just catching a thief; Eric finds a pair of anomalies; G, Sam, and Kensi check out a new firm, where they see clues and overcome three bad guys; Eric describes the facial-recognition hit on one of the guys, which lead the team to conclude that the case is not merely a heist but rather a state-sponsored economic terrorist attack on the financial infrastructure of the USA.

An NCIS agent dies aboard an aircraft carrier at sea; the fearless four, undercover, fly to the ship, where they meet even more problems, but they eventually solve the crimes; Hetty joins them for Christmas underway; Nell catches Eric.

At 03:06 Deeks receives a call from a woman, Jenny, in two of his past lives; she tells about a ring stealing luxury SUVs and shipping them to the Far East; Jenny disappears; the team solve the puzzle, grab the bad guys, and rescue Jenny.

Two weeks ago a Marine lieutenant, Edwin, died in Afghanistan; the local civilian coroner has done an autopsy by the request of the widow, Antonia; she also has hired a private investigator, Stuart, to look into the circumstances; last night someone killed Stuart by slitting his throat; Callen and company investigate. G and Sam meet Antonia, who describes her suspicions about a cover-up; Rose, a medical examiner, explains about the harvesting of tissue, but Antonia objects, saying that Edwin was not an organ donor; Edwin's file has disappeared from the coroner's office. Nate shows up at Hetty's request. Rose becomes a person of interest, and Hetty sends Nate to question her; he takes her to the chat room at the boathouse; a picture begins to appear; Hetty and Nate visit a funeral home, as do G, Sam, Kensi, and Deeks, and they grab the head man; the team finish figuring out the whole thing, and they attend a burial with military honors.

A passenger in a van shoots an LAPD cop, who shoots the driver, then the passenger speeds away; the driver was a Chechen-American with ties to a terrorist network; G goes undercover and into trouble; the team solve the case and rescue G.

In Mexico a US joint team makes a raid to capture the head of a drug cartel; due to a leak the team walks into an ambush; Granger tasks the gang to pinpoint the breach; they go undercover, find the leak, grab the head man, and rescue Nell.

Dean, a fugitive terrorist who disappeared in 1973, stumbles in from a woods, collapses, and dies of a stab wound; G and company investigate; the team find the pieces and fit them together; they find also explosives and one more bad guy.

A thief steals a used notebook computer from a store; a car hits the thief, and two occupants of the car stuff the victim into the back seat; the thief is Amir, the nephew of Yusef, whom Sam still owes on a debt incurred in Afghanistan some years ago; a third occupant of the car, Habib, is a known terrorist; Callen and company investigate (after several tense moments at the start). While Sam visits Yusef, bad guys drive by and open fire; Sam returns fire and drops one of them, Ali, a member of a radical jihadist group; Eric learns that Ali and Amir knew each other; Kensi and Deeks meet Nicole, Amir's girlfriend; Sam follows Ali's brother, then he and G find an arsenal; Kensi and Deeks go back to Nicole's pad, where they find her in trouble, and where they exchange fire with bad guys, rescue Nicole, and see a photograph; Deeks experiences enlightenment; Sam goes back to the boathouse, where he enters a mess; G, Kensi, and Deeks pitch in, then everything works out.

One Russian kills another in the LA area; G and Sam quiz Arkady; Sam and Michelle go back undercover for the CIA; Sam lands in jail, and Hetty leaves him there; Greshnev dies, and Sidorov disappears; Hetty says that this is far from over.

In Idaho someone executes a Marine gunnery sergeant with a pistol; two days before in Los Angeles someone used the same weapon in the same way to kill an Indonesian man; the LA bunch collaborate with an NCIS mobile team. [Continued.]

The G gang and the Red Team continue to pursue Spears and other bad guys; attention turns to a big player in illegal immigration and a man with a red scarf; Hetty sees that Spears is not the executioner, then the teams catch the right one.

During a birthday celebration, 2 sailors and a dancer are poisoned in a bikini bar. When a radical Muslim group appears to take credit for the attack, the team must determine whether there is any truth to the claim.

Nell reports the death of the kingpin of a Mexican drug cartel in a police shootout; the body of the victim disappears from the morgue as soon as it arrives; G and company investigate the possibility of a leak, and they discover the truth.

Gunmen stalk and attack a woman, who disappears; three others die; Hetty cryptically assigns G and company to investigate; Hetty finds the woman, an NCIS agent undercover; the team catch the bad guys; G and Hetty discuss backgrounds.

Monica becomes the target of an unknown shooter in Hollywood; Deeks, in an undercover role as Max (at the direction of Granger), rescues her; Monica is a hostess at a nightclub, which is a property of a South African who's now a legitimate businessman, but who previously worked as an international dealer in illegal arms. G and Sam visit the club, and Nell identifies the shooter as Pieter, an enforcer from South Africa; G and Sam take a different tack with Pieter, so they meet him and take him to the boathouse; Max has an unusual short-term relationship with Monica, who steals blood diamonds and shows them to Max, then both she and the stones disappear, but Kensi and Deeks find her and them. G and Sam chat with Pieter, who reluctantly talks; Kensi and Deeks chat with Monica, who agrees to cooperate; the team monitor an exchange, minimize the damage, and grab three bad guys; later Kensi and Deeks get something clear. Granger never shows up.

A nuclear bomb explodes in a desert in Mexico; G and company investigate; Sam and Michelle go underground; G and Kensi go to Iran and bring back the Chameleon, who takes part in a complex deal to gain the two missing bombs. [Continued.]