LAPD Detective Whiting calls in a favor when Deeks' former partner goes rogue.

The team investigates a ransomware attack that takes out the entire power grid for west L.A. and paralyzes the city. Also, as the first holiday season since the death of Sam’s wife approaches, he struggles to find the best way for his family to celebrate.

NCIS partners with the FBI after a Marine is murdered by a rare nerve gas. Also, Deeks shares his dream to quit law enforcement and open a bar.

The NCIS team investigates the home invasion of Navy Captain Dean Hadlow, who was entertaining his friend, General Omer Abidi of Pakistan, when robbers successfully stole money, jewelry and highly classified information. Also, Deeks and Kensi interview candidates to manage the bar.

After a rise in deaths caused by black market opioid use, the NCIS team links the street drug to funding for terrorist activities

The team helps a former NCIS tech operator search for her missing ex-partner, whom they fear might be working with the gun runners they failed to take down years ago; Deeks reels when his bar gets a negative review.

The NCIS team's murder investigation of a man who sold military information leads to the abduction of a doctor whose cutting edge neurotechnology could be developed into advanced weaponry. Team members are interviewed by FLETC to see if Deeks would make a good NCIS agent. Callen tries to have an important talk with Arkady.

Callen and the team discover that Anna is being held by a group with ties to Anna's upbring and must rescue her before she is forcibly returned to Russia. Also, Admiral Kilbride makes Nell a serious offer.

As Callen continues hunting Katya, Kilbride enlists NCIS to help find a truckload of stolen guns. The assignment becomes more challenging when their suspect, the son of a mob boss they believe was planning to sell them, is found dead.

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.