Gibbs and McGee travel to Russia to safely escort home an NCIS computer engineer with classified intel, but their mission is compromised and they are forced to go off the grid while hunted by a mercenary group.

When a Navy Lieutenant is killed on his way to a private meeting with the President, the NCIS team must determine if the murder was part of a recent stream of muggings in the area or a targeted hit to keep intel secret.

Flashbacks into his past help tell the tale for Dr. Mallard as he and Bishop travel to England in search of answers to find out why an Englishman murdered in the United States would have a list of deceased Navy men on his person.

The Secretary of the Navy assigns the NCIS team to a joint terrorism task force after a Naval research scientist is murdered and the lead suspect is wanted by the Russian government.

During a joint Coast Guard and NCIS training exercise at sea, Gibbs and CGIS Agent Borin spot a deceased man overboard, who is discovered to be a missing crew member from a ship 60 nautical miles away.

The NCIS team must determine if the murder of a Navy Commander's wife is linked to her profession as a therapist or an act of terrorism after finding the Commander's name on a Jihadist target list.

After investigating the murder of a retired Master Sergeant, the NCIS team uncovers a fraudulent charity that preys on those searching for missing military personnel.

Gibbs searches for a way to clear a Navy Hospital Corpsman after she's indicted for illegally providing medical aid to the victims of a hit and run accident.

The NCIS team consults with three cyber-terrorists they imprisoned after a city-wide Internet shutdown the week before Christmas.

The NCIS team investigates copy-cat crime scenes while Gibbs navigates two ex-wives relentlessly trying to get his attention.

The NCIS team searches for a home-grown terrorist after a rescue mission in Syria reveals an American was involved in the capture of a social worker.

Gibbs and the team investigate when a Navy Lieutenant who is set to be the first openly gay service member to receive the Medal of Honor is murdered.

DiNozzo returns to the military academy he attended as a teen after a murdered Marine, who was an alumnus of the school, is found clutching the photo of a current student.

The NCIS team suspects Gibbs' arch-nemesis is behind an explosion at a global terrorism summit.

A covert identity created for one of Gibbs’ undercover cases from 20 years ago resurfaces when a murder victim is found living under the alias.

Evidence in an NCIS murder case reveals a rare painting on loan had been swapped for a fake, prompting DiNozzo, Sr. to share his knowledge and contacts of the black market art world with the team.

After the body of a thief is found in a Marine’s house, NCIS discovers the calling card of a terror group Delilah and the Department of Defense have been tracking.

The murder of a Petty Officer sparks a lead in a 40-year-old airport bombing cold case that Gibbs and DiNozzo have been assigned to for the past two years.

DiNozzo is partnered with his girlfriend ATF Special Agent Zoe Keates after evidence reveals that the murder weapon in an NCIS case was originally purchased for the controversial ATF sting operation “Operation Fast and Furious.”

Gibbs and Bishop travel to Afghanistan after the murder of a Marine in D.C. is linked to a terror group holding another Marine hostage overseas.

Special Agent Ned Dorneget from NCIS cyber operations assists the team when a Navy ensign who worked in the Office of Naval Intelligence is murdered.

The NCIS cyber case turns into a united global effort after evidence confirms “The Calling,” an international terrorist group that recruits children through the internet, has been purchasing S-bombs off the black market.

NCIS feverishly investigates a global terrorist group that is recruiting teens via the Internet, following a deadly bombing overseas that results in an emotional and surprising loss for the team.