The team take a look at a burglary at a cyber-security company, and Callen has to steer clear after Hetty reveals that his girlfriend, Joelle, is one of the main witnesses.

When a suspected North Korean spy is poisoned and hit by a truck carrying Christmas trees, the team must search for who is responsible for smuggling spies into the country. Also, Deeks and Kensi try to find a way to include their mothers in their Christmas plans, and Hetty notices that Granger isn’t feeling the holiday cheer.

Sam receives a distress code from Aiden saying that his school is being taken over by an extremist group.

When an FBI agent is killed while trying to track the location of an undercover agent, NCIS must find the missing agent before the criminals he was investigating do

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.