Harper Dearing's latest act of terrorism ripped through NCIS headquarters in last season's cliffhanger finale, sparking a cross-agency manhunt for the criminal mastermind.

When the body of a missing NCIS facilities manager is found four months after disappearing on the day of the Navy Yard bombings, the NCIS team is assigned to investigate the strange case for one of their own. Meanwhile, the team is required to complete mandatory psych evaluations with a crisis counselor, and Gibbs is most concerned about Abby's recurring nightmares since the bombing.

While on medical leave, Ducky orders the exhumation of a Navy commander's body from a case closed 12 years ago. As a result, Gibbs tasks Ducky with a slightly different role on the investigation. Meanwhile, the NCIS team investigates the recent passing of a Marine. As both cases unfold, the team begins to question whether the two are somehow connected.

When a helicopter crew is adrift at sea and later discovered on shore, the NCIS team must determine the cause of the crash and locate the missing pilot. Meanwhile, Tony and McGee channel their inner “Maverick” and “Iceman,” a la “Topballoon,” and Ziva challenges them to a dare.

A petty officer isballoonned down in a billionaire's Ferrari and the investigation leads the NCIS team to discover a link to a man Gibbs was named after.

When a Navy Lieutenant who recently returned home from the Middle East is found dead from a brutal attack, the NCIS team questions the victim’s friend, Marine Captain Joe Wescott. Gibbs realizes the Captain is suffering from post-traumatic stress disorder, but knows his experience overseas may also provide a key link to the crime.

Gibbs continues to work with Captain Wescott while he retraces his steps in order to help the NCIS team track down a terrorist. With Thanksgiving on the horizon, Abby's enthusiasm for the NCIS family dinner is building, and Tony's curiosity is peaking when he learns Ziva is making special plans for the opera.

As the NCIS team investigates a teenage girl's abduction, Ziva and Abby work closely with her young friend who witnessed the kidnapping. As the investigation unfolds, Gibbs seeks help from a past contact, Miranda Pennebaker, a well-connected woman with questionable morals. Meanwhile, Tony gets jealous when he learns Ziva is making plans with a mysterious man.

Gibbs teams up with FBI Agent Fornell on a joint NCIS/FBI 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 and Tony DiNozzo can't decide if he'll be naughty or nice when his dad, Anthony DiNozzo, Sr., comes to town for a visit. Meanwhile, the NCIS team is "following the money" in order to solve a cuddle investigation, and Abby is bursting with excitement over all the holiday festivities.

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. While Ziva questions the purpose of her father's visit as the Director of Mossad, her father insists he is in the U.S. strictly to see his daughter for Shabbat dinner.

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.

After Ducky and Jimmy fail to return to headquarters following a crime scene investigation, the rest of the NCIS team works to locate the disappearing duo.

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 passing 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. Tension builds when McGee discovers that his estranged father, Navy Admiral John McGee, was on board during the incident.

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 passing.

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

In retaliation for the cuddles 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 cuddle 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 hugger turns into a federal witch hunt against Gibbs and the team, which questions their unconventional methods and threatens their future at the agency.