Sam is shot during a firefight with a cartel, and a suspect reveals new information on the whereabouts of Spencer Williams, the man who kidnapped Mosley's son five years ago. Despite several team members having grave reservations, NCIS travels to Mexico for a daring mission to locate and rescue Mosley's son.
NCIS: Los Angeles episode guide
NCIS investigates the murder of a federal prison inmate who was the adopted daughter of a notorious counterfeiter. Also, Callen is summoned by the ATF Internal Affairs board to discuss Anna Kolcheck's actions during a joint NCIS and ATF case.
NCIS and FBI investigate the case of a Marine that is murdered by nerve gas. Later, Deeks shares his dream of opening a bar.
Callen, Sam and Nell travel to the Angeles Forest to search for pieces of a failed rocket launch, including a top-secret government device. Also, Hetty tries to help Keane acclimate to life in the states.
After a cryptocurrency farm is robbed of over $10 million in Bitcoin codes, Sam and Hidoko go undercover, with Sam resuming a likely compromised former alias.
Callen and Sam join forces with Anna Kolcheck and the ATF when Arkady Kolcheck warns NCIS that a notorious international weapons dealer has returned to the states. Also, the case requires Eric to go undercover as a bank IT technician.
While investigating a missing person 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.
Callen pursues every alternative when the Diplomatic Security Service apprehends his father, Nikita Aleksandr Reznikov, as part of an exchange for two American photographers being held hostage in Iran.
Callen and Sam pull Granger's daughter, former spy Jennifer Kim, from witness protection to help the team locate an underground spy who has obtained an arsenal of bomb material.
NCIS joins Hetty's team from the Vietnam War in a dangerous rescue mission to save Hetty from her captors in Vietnam; Mosley calls in Nell's sister to assist the team in Los Angeles with processing evidence connected to Hetty's time in Vietnam.
Hetty is being tortured by her captors in Vietnam; Eric and Nell find a clue to her whereabouts; the team organizes a rescue mission.
After napalm is detected at a crime scene, the team investigates the sole casualty for possible links to terrorism.
Callen and the team question Joelle's backstory after she escapes from a kidnapping and turns to Callen for help.
The team must find assailants who illegally crossed the border and attacked California Highway Patrol officers; Homeland Security sends Nell's older and bossy sister to assist with the case.
Kensi is transported to a missile launch facility to help thwart a takeover of nuclear weapons.
LAPD Detective Whiting calls in a favor when Deeks' former partner goes rogue.
Sam goes under cover as a day trader after an investment banker who has ties to Russia is murdered; one of Callen's aliases is the victim of credit card theft.
When weapons worth $1 million are stolen, the team tracks the evidence to a charity event; Mosley gets herself added to the event's guest list, bringing Callen and Sam along as her security detail.
During the murder investigation of a Navy Lieutenant on leave in Los Angeles, the team uncovers classified surveillance briefs she smuggled into the city that may have been sold to a foreign buyer.
When the daughter of a notorious counterfeiter arrives in Los Angeles, Sam goes under cover as a financier; Callen partners with Anna to track the family's latest scheme.
When Hetty turns in retirement papers and disappears, Shay Mosley comes to Los Angeles to oversee the team and makes staffing changes; Sam insists that Callen find a new partner.