The exploits of the Los Angeles–based Office of Special Projects (OSP), an elite division of the Naval Criminal Investigative Service that specializes in undercover assignments.
The NCIS team searches for a suspect and their motive following the bombing of a large facility where military combat drones are assembled. Also, Callen and Kilbride get troubling news about a body found in Syria.
After an architect duo who specializes in designing secure buildings is kidnapped, the NCIS team mounts a search to bring them home. Also, Deeks and Kensi realize they may need to get Rosa some help with her schoolwork, and Anna considers a career outside of law enforcement.
The NCIS team join forces with the FBI when a group of grisly murderers known as “The Body Stitchers” returns after evading capture by NCIS years ago. Also, Sam’s dad makes a new friend in Arkady.
When Aiden Hanna's plane crashes and he is accused of being at fault for the accident, the NCIS team must investigate to clear his name; Rountree considers how he wants to handle the aftermath of the incident with the LAPD.
NCIS is called to investigate when a woman is seen fleeing the scene of her husband's murder. Also, Roberta Deeks comes into town to meet Rosa, and Sam looks for another aide for his father.
NCIS is called to investigate after Rear Admiral Ted Gordon is abducted from his home. Also, Kensi struggles with being the fun parent while Deeks is apartment hunting with his mom.
When a Marine falls ill during a training mission due to an attack by a genetic weapon, the NCIS must track down the person responsible for unleashing it. Also, Deeks struggles with balancing work and home life when Rosa comes down with the flu.
NCIS investigates an arson attack at Global West Ventures Corp, a naval defense contractor. Also, Rountree connects with an ex and Kilbride gives Callen files on Pembrook.
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.
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).
When Sam's friend Tom Olsen finds himself being hunted down by enemies from his past, the NCIS team must find out who is after him.
The NCIS team must quickly find Kensi and Fatima after they are kidnapped and drugged while searching for a missing Navy lieutenant who they learn has ties to a dangerous Islamic militia.
When a mystery woman attacks the founder of an AI company, the NCIS team must identify the woman before the next major global conflict ensues. Also, Kilbride's ex-wife, Elizabeth, comes to visit and asks him to think about reconnecting with their son.
When a petty officer is found dead with an apparent suicide note, the NCIS team must investigate the mystery surrounding his death. Also, Callen and Anna begin wedding planning and Sam has a heart to heart with his daughter.
Sam Hanna must go undercover as a fighter to catch the leader of a gang dealing drugs on the streets
When the NCIS team receives a cryptic, urgent message, Fatima and Rountree must work together to solve the case. Also, Kilbride plans to visit his son, and Callen asks Sam to be his best man.
The NCIS team is tasked with assisting NCIS’ cold case homicide unit with a case from 2003 and a missing Navy petty officer. Also, Kilbride and his son, Alex, work to rebuild their relationship.
The NCIS team must investigate when a Navy reservist is stabbed and his lab full of pesticides and insects is ransacked. Kilbride offers Sam the interim operations manager position. Rountree thinks about his future.
When four people, including a CIA officer, are shot and killed in broad daylight, the NCIS team suspects the attacks have something to do with DRONA. Also, Pembrook meets with Callen and gives more insight into his past.
When an ATF agent goes missing, the agency seeks help from the NCIS team to investigate stolen military-grade weapons and locate the agent. Also, Callen and Anna continue to plan their wedding, Rountree’s sister interviews for medical school, and Sam encourages his father to take part in the drug trial.
The NCIS team continues the case with ATF and the stolen weapons. Also, Callen and Anna decide on an impromptu wedding.