An unident young woman dies while making a video recording; the LAPD contacts the NCIS; while investigating, Callen and company find connections and coincidences going back 10 years to Moscow; after hide-and-seek the team cuff the bad guy.

Inside his pad by night G grabs a prowler, who works for Arkady, who gives G a tip; Kensi and her buds run a scam on a foreign businessman; G gets into a firestorm, but the rest of the gang show up and lend a hand.

Kensi and Deeks go undercover as a married couple housesitting in a gated community to identify a Russian sleeper agent believed to live in the neighborhood; a Russian businessman, who's also a link to the unknown agent, dies at a local hotel. G and Sam visit an old Russian friend of G, and Kensi tries to visit an aged neighbor; they all get reactions; Eric finds a lie, so Kensi sniffs around and finds herself in a chick fight; the other girl agrees to tell all, but she too dies; still, though, she gives a Russian name, and she says that he is nearby. G and Sam return to Arkady to find out why he lied; they find the dead body of Arkady's bodyguard plus two men trying to kill Arkady; Kensi and Deeks go to an interesting dinner, and Sam shows G a disturbing image; on the way home Kensi and Deeks run into trouble with a gay couple; however, they discover the Russian long-time sleeper agent, who recently became active. The team finish putting the pieces together.

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.

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.

Someone abducts a German immigrant man; Hetty sends G to Camp Pendleton; everyone else on the team starts working on the abduction; G tails them and joins them; Arkady lends a hand; the gang figure out some of it, and Hetty tells the rest.

The team goes beyond boundaries to make sure Hetty is safe but what they don't know is that Hetty has her own plan as always. Meanwhile Nell is having a hard time after having killed for the first time and is visited by a know face who might be able to help her.

Callen and Sam are surprised when a murder victim turns up alive and wants their help. The NCIS OSP team investigates and finds that someone has broken the rules of sanctions against Russia. Arkady's in trouble again.

Dead Crew members turn up from the missing tanker involved in Arkady's deal with Russia. Arkady's connection to the ship is revealed.

An ongoing case leads Callen, Sam, Deeks, and Kensi to Moscow, where the team must assume multiple undercover identities to locate their suspects. Also, Callen uncovers new information regarding his father.

In order to locate Arkady in Russia, the NCIS team goes undercover with his daughter, Anna, at a gala in Los Angeles to gain access to the Russian Consul General's computer. Part one of two.

In Russia, Callen, Sam and Anna hatch a plan to break Anna's father and his CIA companion out of prison.

The team is shocked to learn that Anna helped a convicted Cuban spy escape U.S. custody before he was to return to his country in a prisoner exchange.

Callen is forced to interrogate his father when he's found in an NCIS patient's hospital during a radiation poisoning case. In the meantime, the team discusses their plans for Thanksgiving.

Sam goes undercover as a day trader after an investment banker who has ties to Russia is murdered.

Callen and Sam join forces with the ATF when a notorious international weapons dealer returns to the States.

The team partners with the State Department after the murder of an arms dealer is connected to a series of crimes that appear to be done by someone with elite forces training.

The team searches for a Marine reservist with a history of PTSD who disappears after a drunk and disorderly altercation.

After Anna Kolchak escapes from prison with her cellmate, Callen and the NCIS team assist with the investigation and try to locate her.

While NCIS investigates the disappearance of a department of defense officer who was looking into a recent UFO sighting, Anna (guest star Bar Paly) makes a bold decision about her future.

When a Russian bomber goes missing while flying over U. S. soil, Callen and Sam must track it down in the desert and secure its weapons and intel before the Russians on board destroy the plane. Also, Hetty gives Nell a cryptic assignment.

The NCIS team's murder investigation of a man who sold military information leads to the abduction of a doctor whose cutting edge neurotechnology could be developed into advanced weaponry.

To rescue Joelle from further torture by the Russians, Callen and NCIS must offer up Anna as bait to Katya. Callen finally discovers who accused him of being Russian spy.

The team discovers that Anna is being held by a group with ties to Anna's upbringing and must rescue her before she is forcibly returned to Russia. Also, Admiral Kilbride makes Nell a serious offer.

NCIS investigates after two men are blown up by their own explosives while attempting to break into a military base. Also, Callen wants to take the next step with Anna, and Sam moves in with his father, Raymond.

The NCIS team hunts for a crew that robs a Los Angeles casino with military-grade power. Also, Kensi and Deeks hear exciting news regarding the adoption, and Callen takes a big step in his relationship with Anna.

When NCIS investigates a shootout on a boat in which a rare cultural artifact is stolen, they're shocked to learn who owns the boat.

When an ATF agent goes missing, the bureau seeks help from the NCIS team to investigate stolen military-grade weapons and locate the agent; Callen and Anna continue to plan their wedding; Rountree's sister interviews for medical school.

Sam and Callen find a way to end the shootout with ATF Adams. Deeks and Bly continue Overwatch and make some decisions that are either exciting or simply dangerous. Nina Barnes goes on an undercover assignment with Sam so Callen can get to an air gaped computer. Undercover ATF comes to an end. Roundtree's sister gets an answer about medical school and they get a response to their lawsuit against LAPD that could change everything for them. Bly and Deeks gets some surprising news. Callen and Anna finally make it to the alter. Then the team prepares for one last mega mission.

When NCIS investigates a shootout on a boat in which a rare cultural artifact is stolen, they're shocked to learn who owns the boat.

After Anna Kolchak escapes from prison with her cellmate, Callen and the NCIS team assist with the investigation and try to locate her.

Callen and Sam are surprised when a murder victim turns up alive and wants their help. The NCIS OSP team investigates and finds that someone has broken the rules of sanctions against Russia. Arkady's in trouble again.

Dead Crew members turn up from the missing tanker involved in Arkady's deal with Russia. Arkady's connection to the ship is revealed.

The team discovers that Anna is being held by a group with ties to Anna's upbringing and must rescue her before she is forcibly returned to Russia. Also, Admiral Kilbride makes Nell a serious offer.

Someone abducts a German immigrant man; Hetty sends G to Camp Pendleton; everyone else on the team starts working on the abduction; G tails them and joins them; Arkady lends a hand; the gang figure out some of it, and Hetty tells the rest.

While NCIS investigates the disappearance of a department of defense officer who was looking into a recent UFO sighting, Anna (guest star Bar Paly) makes a bold decision about her future.

Sam goes undercover as a day trader after an investment banker who has ties to Russia is murdered.

NCIS investigates after two men are blown up by their own explosives while attempting to break into a military base. Also, Callen wants to take the next step with Anna, and Sam moves in with his father, Raymond.

An ongoing case leads Callen, Sam, Deeks, and Kensi to Moscow, where the team must assume multiple undercover identities to locate their suspects. Also, Callen uncovers new information regarding his father.