NCIS investigates the murder of a Navy officer entangled in the world of Hollywood glitz and glamour as the team is joined at Hetty's request by LAPD liaison Marty Deeks.

Callen's ex-partner (Marisol Nichols) takes a Navy recruitment center hostage.

After a rocket engine expert is killed, NCIS tech operator Eric Beale goes undercover for the first time to ensure that the classified technology used to build satellites is safe.

The NCIS team joins forces with the NSA to find the creator and controller of a software program linked to a cyber attack against the Department of Defense. Meanwhile, Callen continues searching for more information about his past.

When a vehicle transporting Jada Khaled is ambushed, NCIS must track down the culprit to save her and their case. Meanwhile, Sam is forced to confront Jada for the first time since returning from Sudan.

When a former Marine is suspected of creating a chemical bomb, the NCIS: LA team joins the FBI’s domestic terrorist task force including Operational Psychologist Nate Getz.

When a gang identifies and executes an undercover agent, the team must locate a mole before other agents are put in danger.

The Department of Justice target a member of the team. Leon delivers unsettling news to Hetty.

The mole has once again compromised the NCIS team as planted evidence results in the arrests of Callen, Sam, Granger and Deeks, on the day Under Secretary Duggan (Jackson Hurst) returns for Hetty’s resignation.

The NCIS team investigates a defense contractor, Rebecca Larmont, designing a nuclear attack weapon after her estranged husband, Victor Larmont, says he has proof she is selling Navy secrets to a foreign government. Also, Kensi goes undercover as a professional dancer at the Cuban club where the husband works, while Deeks is undercover as the bathroom attendant.

After weapons with a $1 million street value are stolen, the team tracks the evidence to a wealthy charity event, prompting Mosley to be added to the guest list with Callen and Sam as her security detail.

While investigating a missing person’s case, the team uncovers a killer who puts on shows for high-paying voyeurs. Also, Mosley assigns Callen as her partner on a joint ATF mission to apprehend someone from her past.

The NCIS team partners with the State Department after the murder of an arms dealer is connected to a series of crimes seemingly executed by someone with elite special forces training. Also, Callen visits ATF Agent Anna Kolcheck in prison as she awaits her sentencing.

The NCIS team partners with the FBI to locate a terrorist cell in Los Angeles believed to be preparing for an imminent attack.

Callen and Sam work with Navy Captain Harmon "Harm" Rabb, Jr. (David James Elliott) to locate a group of ISIS sympathizers aboard the USS Allegiance. Also, Hetty enlists her friend, Lieutenant Colonel Sarah "Mac". Mackenzie (Catherine Bell), to help obtain information from a Russian diplomat.

Faced with multiple cases worldwide, the NCIS team splits up, with Callen and Sam working with Mossad Agent Eliana Sapir in Tel Aviv, and Kensi partnering with DOJ Agent Lance Hamilton in Los Angeles.

Akhos Laos , a former black ops agent originally recruited and trained by Hetty Lange, returns to seek revenge on Hetty for the life she introduced him to, on the 250th episode

When Fatima is captured while on a mission and held for ransom, Callen and Sam enlist a deep undercover CIA agent, Kadri, to help get her back.

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. Meanwhile, Hetty gives Nell a cryptic assignment.

When Nell sends Sam to meet an informant who plans to blow the whistle on a military secret, Hanna's life is in danger when the man tries to run him down and kill him. Also, Kensi and Deeks debate whether or not to buy their first house.

When military grade technology is stolen, a deaf engineer, Sienna Marchione, who always wanted to serve her country, and the only member of her team to survive the theft, helps Kensi and NCIS track down the tech before it’s taken out of the country.

While Callen suspects Hetty of keeping secrets about his past and Joelle surfaces in her quest to capture Katya, NCIS must track down an informant whose life is in danger. Also, Kensi and Deeks work to expand their family.

NCIS takes the case personally when an LAPD officer’s father, a beloved elderly Japanese American veteran, is the victim of a vicious hate crime.

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.

While Agent Rountree and Fatima are searching for Kilbride, who has been MIA, they are ambushed and learn that every member of the team has a $200,000 bounty on their head via the dark web. The NCIS team must save Agent Rountree and find Kilbride while every cartel, hit man, gang and psychopath hunts them down.

The crossover starts on NCIS S20E10 Too Many Cooks (I) and NCIS: Hawai'i S02E10 Deep Fake (II).