Gibbs goes on the hunt to find Harper Dearing and bring him down following the NCIS headquarters bombing.

The NCIS team investigates the cause of a mysterious death involving a NCIS armory employee that was found four months after the Navy Yard bombings. Meanwhile, the team has to undergo mandatory psych evaluations, causing Gibbs to worry about Abby.

While on medical leave, Ducky decides to reopen a 12-year-old case by ordering the exhumation of a Navy commander's body. Meanwhile, the team also investigates a recent death of a Marine that may be tied to Ducky's old case.

When a petty officer is murdered in a billionare's Ferrari, the NCIS team stumbles upon Gibbs' namesake.

The NCIS team has to find out the cause of the helicopter crash that was found on shore and locate the missing pilot. Meawhile, Ziva issues a dare to Tony and McGee.

The NCIS team investigates the brutal murder of a Navy Lieutenant who just returned home from the Middle East.

Gibbs continues to work with a Marine Captain sufferingfrom PTSD in an investigation to track down a terrorist.

The NCIS team investigates a teenage girl's abduction while Ziva and Abby team up to protect her friend who witnessed the kidnapping while Gibbs seeks information from a past connection.

Gibbs teams up with Fornell on a joint investigation after Fornell becomes the target of a shooting, but they face an unexpected twist in the case when their mutual ex-wife, Diane Sterling, gets involved. Meanwhile, rumors run wild among the group after Diane stays overnight at McGee's.

It's Christmas time for the DiNozzos when Tony's dad comes to visit. Meanwhile, the NCIS team is "following the money" in order to solve a murder investigation.

While the NCIS team investigates the link to a dead journalist and a Navy petty officer, Ziva is taken aback by the sudden emotional visit by her father, who she hasn't seen in more than two years.

In the aftermath of an event that strikes close to home, the NCIS team unites to seek answers and demand justice in order to protect their most vulnerable colleagues.

The NCIS team investigates a Marine’s car accident and ignites some upsetting past memories for Abby as a young girl on the trail of her first “case.”

The NCIS team takes on a renowned hacker who could hold the key to tracking down the most-wanted cyber-terrorist in the world.

On leave from NCIS while still grieving the loss of his wife and his kids' mother, Director Vance discovers unexpected personal information that causes him to question everything.

The NCIS team races to track down Ducky and Jimmy after the two disappear while transporting a body from a crime scene.

A media frenzy surrounding an unidentified criminal prompts Gibbs’ barber to question his son’s involvement and ask for Gibbs’ help in ruling out his son as a prime suspect.

The wife of a Marine who specialized in K-9 bomb detection urges the NCIS team to investigate the recent death of her husband in Afghanistan. Meanwhile, Director Vance asks for the team's assistance as he interviews nannies.

A massive storm brings the NCIS team aboard the USS Borealis, where everyone becomes a suspect once the crime scene proves that Mother Nature wasn't the only culprit.

When a Navy reservist returns home to find her husband missing and her living room covered in blood, she turns to the NCIS team to bring him home. Meanwhile, Tony suspects that Ziva is planning a risky move to avenge her father's death.

While the NCIS team investigates the murder of a Mossad officer in Virginia, Tony and Ziva depart for Berlin as they track her father's killer.

In retaliation for the murders of Eli David and Jackie Vance, the NCIS team feverishly searches for Bodnar despite orders from Homeland Security to relinquish the case.

A Department of Defense investigator scrutinizes the NCIS team's response to the Bodnar case involving the murder of Ziva's father and Vance's wife. Meanwhile, the team examines whether a Petty Officer is suffering from paranoia or if his claims of being followed are tied to a matter of national security.

The international manhunt for Eli David and Jackie Vance's killer turns into a federal witch hunt against Gibbs and the team, which questions their unconventional methods and threatens their future at the agency, on the 10th season finale.