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.
Sam and Kilbride clash when a case involving an arms dealer responsible for the slaughter of ATF agents leads them to a well-connected colonel and friend of Kilbride, accused of supplying militia groups with guns.
As Callen continues hunting Katya, Kilbride enlists NCIS help to find a truckload of stolen guns; the assignment becomes more challenging when their suspect is found dead.
When an NCIS mission to protect a compromised undercover agent goes completely sideways, the agents are individually interrogated to find out what really happened; Kilbride must make a difficult decision.
Sam negotiates and Rountree goes undercover, when a man takes a busload of hostages and threatens to blow it up unless his daughter's war crimes are posthumously cleared.
NCIS investigates the apparent suicide of a Navy intelligence officer who leapt to his death after taking LSD. Also, while Kensi is away, Deeks makes plans to redo the backyard without her input.
The NCIS team scrambles to find Kensi, when she is attacked and kidnapped by a mysterious militia group while helping a group of migrants cross the border.
The NCIS team helps a U.S. ambassador search for her missing daughter, Gia, a popular social media influencer. Also, Agent Aliyah De León returns to support the team with the case.
When a civilian scientist working with the marines is killed and her advanced radar technology stolen, the team must scramble to find the missing technology and the culprit.
When a newborn is found abandoned on a Navy ship, Kensi and Deeks search for the mother on board before she dies of complications; Nate meets with Adm. Kilbride and learns about the CIA project from the '70s and '80s involving children.
The NCIS team investigates an unidentified aircraft that flies into U.S. airspace and crashes into a Navy plane. Also, Deeks and Kensi begin to prepare for their foster inspection.
When DOJ Agent Lance Hamilton's partner is killed, Sam dons his previous undercover persona of "Switch" to find the culprit. Also Kensi, Deeks, Roundtree and Kilbride work to catch an aerospace engineer who stole classified Navy schematics.
NCIS investigates the robbery of a high-end arts storage by going undercover as potential buyers on the black market, to find who is behind the stolen items.
Rountree and his younger sister are pulled over by police and treated harshly in a clear case of racial profiling. Also, NCIS investigates the death of a Navy photographer who was assigned to document the building of a new weapons station.
NCIS investigates the kidnapping of Master Sergeant Boomer, a military working dog. Also, Sam looks to sell his boat so he can take care of his father who is suffering from Alzheimer's.
NCIS helps Naval intelligence officer Akhil Ali locate a fellow officer who went missing while recruiting foreign assets as sources of intelligence. Callen and Nate Getz track down a man Callen believes was present for his training.
NCIS investigates the murder of a woman employed in the Navy's missile defense program and its connection to stolen Navy missile technology. Also, a strict social worker stresses out Deeks, and Sam debates selling his boat.
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.
