When a Russian bomber goes missing while flying over U. S. soil, Callen and Sam must track it down in the desert and secure its weapons and intel before the Russians on board destroy the plane. Also, Hetty gives Nell a cryptic assignment.

As the trial begins of a Chief Petty Officer who Callen and Sam arrested for war crimes last year, the NCIS team is called to help find the missing star witness.

When Nell sends Sam to meet an informant who plans to blow the whistle on a military secret, Hanna's life is in danger when the man tries to run him down and kill him. Also, Kensi and Deeks debate whether or not to buy their first house.

The body of a murdered Navy reservist is found by thieves in the midst of a robbery, and NCIS must work with the burglars to find the killer; Kensi and Deeks struggle to decide if they are ready to make the leap to buys a house.

To get intel on a matter of national security, Kensi must come face-to-face with a sociopath who has been obsessed with her since she put him in jail years ago; Deeks is desperate to keep Kensi safe, but he is forced to leave NCIS.

Before Christmas, Hetty assigns Callen the case of his former foster brother and his wife, who, upon reentry into the U.S., are framed for smuggling drugs across the border; Deeks is struggling with losing his job at NCIS.

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.

When NCIS investigates the murder of a man about to reveal the source of a massive counterfeiting operation, an old acquaintance becomes their prime suspect and reveals the true reason for her return.

While NCIS must track down an organized crime leader who is trying to buy stolen defense technology, Callen goes to Anna to ask the ultimate question, and Deeks is kicked out of NCIS training, Hetty has a life-changing surprise for him.

When Sam's daughter, Kam, is kidnapped after leading citywide protests, he will stop at nothing to find her. Also, Deeks rejoins NCIS and Callen searches for answers about Anna.

After Callen receives a cryptic message from Hetty, he tracks down the person tailing him, bringing him to a remote location teeming with Russians - and face to face with Anna.

To rescue Joelle from further torture by the Russians, Callen and NCIS must offer up Anna as bait to Katya. Callen finally discovers who accused him of being Russian spy.

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

Deeks is kidnapped by an associate of Kirkin's in need of his help and NCIS investigates the shooting of a militarized dolphin equipped with a Russian microchip. Also, Beale makes Nell an interesting offer and Hetty returns.